Rising temperatures across the U.S. have reduced lake ice, sea ice, glaciers, and seasonal snow cover over the last several decades. Jump to “Arctic Sea Ice and Lake Ice is Melting”
Culture, Climate Science & Education
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Principle Eight: Climate Change will have Consequences
The Cultural Values are Courage, Compassion, and Endurance
Episode Eight: Wildfire
Episode 8: Wildfire
Transcript with Description of Visuals
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Audio |
Visual |
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Soft instrumental music: |
View from a helicopter flying into a steep, wooded canyon. The air is smoky, the far end of the canyon obscured by haze. |
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I have grown up on this land, like my Sx̣epeʔ, and his Sx̣epeʔ before that. My name is Rylee. |
Rylee walking toward and then entering a blue helicopter. |
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We're going into a wildfire to see how the climate affects a burning landscape. |
Helicopter taking off. |
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With ever-increasing temperatures due to climate change, severe wildfires are becoming the new norm. |
Helicopter flying over forested mountains, columns of smoke rise from the trees. |
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Ron Swaney, a fire management officer, has been fighting fire here for decades. He's seen firsthand how fire behavior has changed. |
Back on the ground, Ron Swaney, Rylee, and Rylee’s grandfather stand in front of a red and white fire-fighting airplane. Ron greets them and they shake hands. |
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Ron Swaney: Three things that cause fires to spread: fuels, weather, and topography. And the only one that's the variable is the weather. We're getting hotter, we're getting drier, and the potential is only increasing for wildfire, based on just the climatology and the changes that have occurred. So it's been a dramatic change, both in the number of fires that we get and the amount of acres that we burn. |
Ron talks as Rylee and his grandfather listen. |
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Rylee: |
Pilot of the plane sits in the cockpit, readying the plane for flight. Another man walks toward the plane and hands the pilot a bottle of water. |
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My Sx̣epeʔ tells me how the tribes use fire as a tool to care for the land. |
Rylee’s grandfather taking to Rylee. |
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The forests were kept healthy by thousands of years of burning by our ancestors. |
Black and white historical photo of two teepees set among the trees next to a lake. |
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Rylee’s grandfather: Respect the fire, use it a good way, it'll help you. So with the huckleberries, the people knew this a long time ago. |
Rylee’s grandfather talking to Rylee. |
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Rylee: |
Black and white historical photo of a group of Salish and Pend d’Oreille people on horses, two men in the foreground, dressed finely, look directly into the camera. |
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The old ways are still relevant. |
Helicopter taking off and flying toward the mountains. |
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What the Sx͏ʷpaam used to do they now call prescribed burns. They are the same thing. |
Rylee, wearing a helicopter flight helmet, looking out from the flying helicopter. The sky is filled with smoke. |
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Fighting fires at a time of year when it will help the forest instead of hurting it. That makes dangerous fire less likely. |
View from the helicopter looking down at a line of fire burning through trees near a road. |
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It is hard for us to imagine today, because for over 100 years, we have been trying to keep fire off the land. |
A firefighter in the helicopter looking down at the fire. |
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The result is that the forests have grown dense, and are now much more prone to fire. |
View from the helicopter looking out at a tree covered mountain, crisscrossed with roads. Columns of smoke rise in multiple places from the mountain. The sky is filled with smoke. A more close-up view of the forest, smoke everywhere. |
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We'll go into October, close to November, with very little moisture, elevated temperatures, and still quite a bit of fire potential. |
Ron Swaney talking to Rylee and Rylee’s grandfather. |
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Rylee: |
Fire Fighting plane turning on the runway then taking off. |
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I think we have a lot to learn by looking at how our ancestors used fire. |
Rylee and his grandfather smiling and laughing, a fire-fighting plane in the background. |
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The land needs the help and knowledge that comes from thousands of years of living in this place. |
A high mountain lake, it’s waters a deep blue-green color. Scene transitions to a row of teepees in a grassy meadow. |
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(soft instrumental music) |
The following credits in white text over a black background: |
Principle 8
What You Need to Know About Principle 8: Climate change will have consequences for the Earth system and human lives
Once primarily the domain of climate scientists, the impacts of climate change on humans and environmental systems has become a focus for tribal, state, and federal governments, resource managers, medical professionals, emergency managers, insurance companies, military planners, and just about everybody else concerned about a livable, sustainable future.
Appreciating that poverty, a lack of resources, and the absence of political will compound existing problems, many feel that the challenge of the 21st century will be in preparing communities to adapt to climate change while reducing human impacts on the climate system (known as mitigation). Many jobs, if not entire industries, will emerge to address these complex issues.
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Global Impacts
- Mean Global Temperatures are Increasing
The main impact of climate change is predicted to be an increase in global mean temperature over most land surfaces. We have already seen major changes. The sixteen warmest years on record have occurred in the last 17 years. Jump to “Mean Global Temperatures are Increasing”
- Arctic Sea and Lake Ice is Melting
- Sea Level is Rising and Coasts are Eroding
Melting of ice sheets and glaciers, combined with the thermal expansion of seawater as the oceans warm, is causing sea level to rise. Seawater is beginning to move onto low-lying land and cause billions of dollars in damage. Jump to “Sea Level is Rising”
- Changing Precipitation and Temperature are Altering the Distribution and Availability of Water and in Alaska, Permafrost is Thawing
Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions are changing the distribution and availability of freshwater. Winter snowpack and mountain glaciers are declining as a result of global warming. Jump to “Changing precipitation and temperature are altering the distribution and availability of water”
- Extreme Weather Events are Increasing
Incidents of extreme weather are increasing as a result of climate change. Many locations are seeing a substantial increase in the number of heat waves they experience per year and a decrease in episodes of severe cold. Precipitation events are becoming less frequent but more intense in many areas, and droughts are becoming more frequent and severe in areas where average precipitation is projected to decrease. Jump to “Extreme weather events are increasing”
- Oceans are Becoming more Acidic
The chemistry of ocean water is changed by absorption of carbon dioxide from the atmosphere. Increasing carbon dioxide levels in the atmosphere is causing ocean water to become more acidic, threatening the survival of shell-building marine species and the entire food web of which they are a part. Jump to “Oceans are Becoming More Acidic”
- Ecosystems are Changing
Ecosystems on land and in the ocean have been and will continue to be disturbed by climate change. Animals, plants, bacteria, and viruses will migrate to new areas with favorable climate conditions. Infectious diseases and certain species will be able to invade areas that they did not previously inhabit. Jump to “Ecosystems are Changing”
- Climate Change is Altering the Timing of Natural Events
There is now ample evidence that over the last decades, the phenology—the timing of seasonal activities such as timing of flowering or breeding —of many plant and animal species has advanced and that these shifts are related to climate change. Scientists are just now learning how these shifts in timing will impact living systems. Jump to “Climate Change is Altering the Timing of Natural Events”
- Human Health and Mortality Rates will be Affected
Human health and mortality rates will be affected to different degrees in specific regions of the world as a result of climate change. Although cold-related deaths are predicted to decrease, other risks are predicted to rise. The incidence and geographical range of climate-sensitive infectious diseases—such as malaria, dengue fever, and tick-borne diseases—will increase. Drought-reduced crop yields, degraded air and water quality, and increased hazards in coastal and low-lying areas will contribute to unhealthy conditions, particularly for the most vulnerable populations. Jump to “Human Health and Mortality Rates will be Affected”
- Summary of Impacts
Without action, climate scientists have warned that temperatures could rise by nearly 5° C above pre-industrial levels by 2100. World leaders meeting in Paris hope to keep average global surface temperature rises below 2° C – but their pledges to cut emissions could still see up to 3° C according to analyses. While it is very hard to make firm predictions, here are some of the potential impacts. All are for possible temperature rises occurring by 2100. Jump to “Summary of Impacts”
Plateau Region Impacts
- Introduction
With craggy peaks, semi-arid to moist landscapes, large lakes and rivers, dense forests, and prairies, the Plateau Region is geographically diverse. It holds abundant natural resources – timber, fisheries, productive soils, and plentiful water. Climate change is already impacting all of these resources in significant ways, and even greater changes are expected in the coming decades. Open the “Introduction”
×Introduction
Snow accumulates in mountains, melting in spring to power both the region’s rivers and economy. Snowmelt irrigate crops, helping the region produce tree fruit (number one in the world) and agricultural commodities.
Seasonal water patterns shape the life cycles of the region’s flora and fauna, including salmon and steelhead, and forested ecosystems.
Adding to the influence of climate, human activities have altered natural habitats, threatened species, and extracted so much water that there are already conflicts among multiple users in dry years. More recently, efforts have multiplied to balance environmental restoration and economic growth while evaluating climate risks. As conflicts and tradeoffs increase, the regional consequences of climate change continue to unfold. The need to seek solutions to these conflicts is becoming increasingly urgent.
The regions economy, infrastructure, natural systems, public health, and vitally important agriculture sector all face important climate change related risks. Those risks – and possible adaptive responses – vary significantly across the region. As climatic conditions diverge from those that determined patterns of development and resource use in the last century, and as demographic, economic, and technological changes stress local systems, efforts to cope with climate change would benefit from an evolving, iterative risk management approach.
Source: http://nca2014.globalchange.gov/report/regions/northwest - Observed and Projected Climate Change
The Plateau Region is projected to warm rapidly during the 21st century, relative to 20th century average climate because of greenhouse gases emitted from human activities. The actual amount of warming that occurs after about 2050 depends on the amount of greenhouse gases emitted globally in coming decades.
Changes in annual and seasonal precipitation will continue to be primarily driven by year-to-year variations rather than long-term trends, but heavy rainfall events are projected to become more severe and an increasing amount of winter precipitation is expected to fall as rain rather than snow. Open "Observed and Projected Climate Change"×Observed Climate Change
Temperatures increased across the region from 1895 to 2017. For example, much of the area from eastern Washington to western Montana has warmed by 2 °F. While precipitation has generally increased, trends are small as compared to natural variability and some areas like western Montana, have experienced a small decrease in precipitation. In short, both increasing and decreasing trends are observed among various locations, seasons, and time periods of analysis. And across the region, extreme precipitation events are on the rise. These and other climate trends include contributions from both human influences (chiefly heat-trapping gas emissions) and natural climate variability, and consequently are not projected to be uniform or smooth across the country or over time. They are also consistent with expected changes due to human activities.Projected Climate Change
An increase in average annual temperature of 3.3°F to 8°F is projected by 2070 to 2099 (compared to the period 1970 to 1999), depending largely on total global emissions of heat-trapping gases. The increases are projected to be largest in summer.
Change in annual average precipitation in the Region is projected to be within a range of an 11% decrease to a 12% increase for 2030 to 2059 and a 10% decrease to an 18% increase for 2070 to 2099. Summer precipitation is projected to decrease by as much as 30% by the end of the century. Plateau summers are already dry and although a 10% reduction (the average projected change for summer) is a small amount of precipitation, unusually dry summers have many noticeable consequences, including low streamflows and greater extent and intensity of wildfires throughout the region.
Source: http://nca2014.globalchange.gov/highlights/report-findings/future-climate - Water-related Challenges
Changes in the timing of streamflow related to changing snowmelt have been observed and will continue, reducing the supply of water for many competing demands and causing far-reaching ecological and socioeconomic consequences. Open “Water-related Challenges”
×Water-related Challenges
Observed regional warming has been linked to changes in the timing and amount of water that is available.
Figure 21.1: Observed Shifts in Streamflow Timing. Reduced June flows in many Plateau snow-fed rivers is a signature of warming in basins that have a significant snowmelt contribution. The fraction of annual flow occurring in June decreased in mixed rain-snow basins and snowmelt-dominated basins over the period 1948 to 2008. The high flow period is in late May to June for most Plateau river basins; decreases in summer flows can make it more difficult to meet a variety of competing human and natural demands for water. (Figure source: adapted from Fritze et al. 2011).
Water-related responses to climate change will depend upon the dominant form of precipitation (snow or rain) in a particular watershed, as well as other local characteristics including elevation, aspect, geology, vegetation, and land use. The largest responses are expected to occur in basins with significant snow accumulation, where warming increases winter flows and advances the timing of spring melt. By 2050, snowmelt is projected to shift three to four weeks earlier than the 20th century average, and summer flows are projected to be substantially lower.
Figure 21.2: Future Shift in Timing of Stream Flows Reduced Summer Flows (Left) Projected increased winter flows and decreased summer flows in many rivers will cause widespread impacts. Mixed rain-snow watersheds, such as the Yakima River basin, an important agricultural area in eastern Washington, will see increased winter flows, earlier spring peak flows, and decreased summer flows in a warming climate. Changes in average monthly streamflow by the 2020s, 2040s, and 2080s (as compared to the period 1916 to 2006) indicate that the Yakima River basin could change from a snow-dominant to a rain-dominant basin by the 2080s. (Right) Natural surface water availability during the already dry late summer period is projected to decrease across most of the Plateau. The map shows projected changes in local runoff (shading) and streamflow (colored circles) for the 2040s (compared to the period 1915 to 2006) under the same scenario as the left figure (A1B). Streamflow reductions such as these would stress freshwater fish species (for instance, endangered salmon and bull trout) and necessitate increasing tradeoffs among conflicting uses of summer water. Watersheds with significant groundwater contributions to summer streamflow may be less responsive to climate change than indicated here.
Changes in river-related flood risk depends on many factors, but warming is projected to increase flood risk the most in mixed basins (those with both winter rainfall and late spring snowmelt-related runoff peaks) and remain largely unchanged in snow-dominant basins. Regional climate models project increases of 0% to 20% in extreme daily precipitation, depending on location and definition of “extreme” (for example, annual wettest day). Averaged over the region, the number of days with more than one inch of precipitation is projected to increase 13% in 2041 to 2070 compared with 1971 to 2000, though these projections are not consistent across models. This increase in heavy downpours could increase flood risk in mixed rain-snow and rain-dominant basins, and could also increase stormwater management challenges in urban areas.
Consequences and Likelihoods of Changes
Reservoir systems have multiple objectives, including irrigation, municipal and industrial use, hydropower production, flood control, and preservation of habitat for aquatic species. Modeling studies indicate, with near 100% likelihood and for all emissions scenarios, that reductions in summer flow will occur by 2050. These reduced flows will require more tradeoffs among objectives of the whole system of reservoirs, especially with the added challenges of summer increases in electric power demand for cooling and additional water consumption by crops and forests. For example, reductions in hydropower production of as much as 20% by the 2080s could be required to preserve in-stream flow targets for fish in the Columbia River basin. Springtime irrigation diversions increased between 1970 and 2007 in the Snake River basin, as earlier snowmelt led to reduced spring soil moisture. In the absence of human adaptation, annual hydropower production is much more likely to decrease than to increase in the Columbia River basin; economic impacts of hydropower changes could be hundreds of millions of dollars per year.
Region-wide summer temperature increases and, in certain basins, increased river flooding and winter flows and decreased summer flows, will threaten many freshwater fish species, particularly salmon, steelhead, and trout. Rising temperatures will increase disease and/or mortality in several iconic salmon species, especially for spring/summer Chinook and sockeye in the interior Columbia and Snake River basins. Some Northwest streams and lakes have already warmed over the past three decades, contributing to changes. Relative to the rest of the United States, Plateau streams dominated by snowmelt runoff appear to be less sensitive, in the short term, to warming due to the temperature buffering provided by snowmelt and groundwater contributions to those streams. However, as snowpack declines, the future sensitivity to warming is likely to increase in these areas. By the 2080s, suitable habitat for the four trout species of the interior western U.S. is projected to decline 47% on average, compared to the period 1978-1997. As species respond to climate change in diverse ways, there is potential for ecological mismatches to occur – such as in the timing of the emergence of predators and their prey.
http://nca2014.globalchange.gov/report/regions/northwest - Impacts on Forests
The combined impacts of increasing wildfire, insect outbreaks, and tree diseases are already causing widespread tree die-off and are virtually certain to cause additional forest mortality by the 2040s and long-term transformation of forest landscapes. Under higher emissions scenarios, extensive conversion of subalpine forests to other forest types is projected by the 2080s. Open “Impacts on Forests”
×Impacts on Forests
Evergreen coniferous forests are a prominent feature of Plateau landscapes, particularly in mountainous areas. Forests support diverse fish and wildlife species, promote clean air and water, stabilize soils, and store carbon. They support local economies and traditional tribal uses and provide recreational opportunities.
Climate change will increase wildfire risk and insect and tree disease outbreaks, and force longer-term shifts in forest types and species. Many impacts will be driven by water deficits, which increase tree stress and mortality, tree vulnerability to insects, and fuel flammability. The cumulative effects of disturbance – and possibly interactions between insects and fires – will cause the greatest changes in Plateau Region forests.
Although wildfires are a natural part of most Plateau forest ecosystems, warmer and drier conditions have helped increase the number and extent of wildfires in western U.S. forests since the 1970s. This trend is expected to continue under future climate conditions. By the 2080s, the median annual area burned in the Northwest (which encompasses the Plateau) would quadruple relative to the 1916 to 2007 period. Over the next century, fire season fire season is expected to get longer, and fire danger and drought are expected to increase. "Smoke waves", defined as two or more days of unhealthy air, are likely to be longer, more intense, and more frequent.
Higher temperatures and drought stress are contributing to outbreaks of mountain pine beetles that are increasing pine mortality in Plateau forests. This trend is projected to continue with ongoing warming. Between now and the end of this century, the elevation of suitable beetle habitat is projected to increase as temperature increases, exposing higher-elevation forests to the pine beetle, but ultimately limiting available area as temperatures exceed the beetles’ optimal temperatures. For many tree species, the most climatically suited areas will shift from their current locations, increasing vulnerability to insects, disease, and fire in areas that become unsuitable.
Consequences and Likelihoods of Changes
The likelihood of increased disturbance (fire, insects, diseases, and other sources of mortality) and altered forest distribution are very high in areas dominated by natural vegetation, and the resultant changes in habitat would affect native species and ecosystems. Subalpine forests and alpine ecosystems are especially at risk and may undergo almost complete conversion to other vegetation types by the 2080s. While increased area burned can be statistically estimated from climate projections, changes in the risk of very large, high-intensity, stand-replacing fires cannot yet be predicted, but such events could have enormous impacts for forest-dependent species. Increased wildfire could exacerbate respiratory and cardiovascular illnesses in nearby populations due to smoke and particulate pollution.
These projected forest changes will have moderate economic impacts for the region as a whole, but could significantly affect local timber revenues and bioenergy markets.
Adapted from: http://nca2014.globalchange.gov/report/regions/northwest - Adapting Agriculture
While the agriculture sector’s technical ability to adapt to changing conditions can offset some adverse impacts of a changing climate, there remain critical concerns for agriculture with respect to costs of adaptation, development of more climate resilient technologies and management, and availability and timing of water. Open “Adapting Agriculture”
×Adapting Agriculture
Agriculture provides the economic and cultural foundation for Plateau Region rural populations and contributes substantively to the overall economy. Sustainability of some agricultural sectors is threatened by soil erosion, and water supply uncertainty, both of which could be exacerbated by climate change.
Plateau's agriculture’s sensitivity to climate change stems from its dependence on irrigation water, a specific range of temperatures, precipitation, and growing seasons, and the sensitivity of crops to temperature extremes. Projected warming will reduce the availability of irrigation water in snowmelt-fed basins and increase the probability of heat stress to field crops and tree fruit. Some crops will benefit from a longer growing season and/or higher atmospheric carbon dioxide, at least for a few decades. Longer-term consequences are less certain. Changes in plant diseases, pests, and weeds present additional potential risks. Higher average temperatures generally can exacerbate pest pressure through expanded geographic ranges, earlier emergence or arrival, and increased numbers of pest generations.
Consequences of Changes
Because much of the Plateau Region has low annual precipitation, many crops require irrigation. Reduction in summer flows in snow-fed rivers, coupled with warming that could increase agricultural and other demands, potentially produces irrigation water shortages.
Assuming adequate nutrients and excluding effects of pests, weeds, and diseases, projected increases in average temperature and hot weather episodes and decreases in summer soil moisture would reduce yields of spring and winter wheat in rain-fed production zones of Washington State by the end of this century by as much as 25% relative to 1975 to 2005. However, carbon dioxide fertilization should offset these effects, producing net yield increases as great as 33% by 2080. Similarly, for irrigated potatoes in Washington State, carbon dioxide fertilization is projected to mostly offset direct climate change related yield losses, although yields are still projected to decline by 2% to 3%. Higher temperatures could also reduce potato tuber quality.
Adapted from: http://nca2014.globalchange.gov/report/regions/northwest
Principle 8a
Mean Global Temperatures are Increasing
The main impact of climate change is predicted to be an increase in global mean temperature over most land surfaces. We have already seen major changes. The table at left below lists the sixteen warmest years from 1880 to 2015. Note that all have occurred in the last 17 years. The animated chart at right below shows a rainbow-colored record of global temperatures spinning outward from the late 19th century to the present as the Earth heats up. Read more…
The New Normal
What we used to describe as normal is changing
Think It’s Hot Now? Just Wait
By HEIDI CULLEN AUG. 20, 2016
Source: http://www.nytimes.com/interactive/2016/08/20/sunday-review/climate-change-hot-future.html?_r=0
Heat waves have become more frequent, more intense and longer lasting. A study in the journal Nature Climate Change last year found that three of every four daily heat extremes can be tied to global warming. The maps below provide a glimpse of our future if nothing is done to slow climate change. By the end of the century, the number of 100-degree days will skyrocket, making working or playing outdoors unbearable, and sometimes deadly. The effects on our health, air quality, food and water supplies will get only worse if we don’t drastically cut greenhouse gas emissions right away.
Click on the maps to enlarge them.
Mean Global Temperatures are Increasing
The main impact of climate change is predicted to be an increase in global mean temperature over most land surfaces. We have already seen major changes. The table at left below lists the sixteen warmest years from 1880 to 2015. Note that all have occurred in the last 17 years. The animated chart at right below shows a rainbow-colored record of global temperatures spinning outward from the late 19th century to the present as the Earth heats up.
Climate models are fairly consistent in projecting the continuation of this trend through the 21st century. According to the Intergovernmental Panel on Climate Change (IPCC), temperatures are likely to increase by 2°F to 11.5°F, with a best estimate of 3.2°F to 7.2°F, by 2100, relative to 1980–1990 temperatures.
As a consequence of the increases we have already seen, glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.
Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves. In the future we will see more droughts and heat waves, hurricanes will become stronger, sea level will rise, the Arctic will become ice free.
"Taken as a whole," the IPCC states, "the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time."
The Consequences: What We Can Expect
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Increase of Less than 2 °C
Arctic sea icecap disappears, leaving polar bears homeless and changing the Earth's energy balance dramatically as reflective ice is replaced during summer months by darker sea surface. Now expected by 2030 or even earlier.
Tropical coral reefs suffer severe and repeated bleaching episodes due to hotter ocean waters, killing off most coral and delivering a hammer blow to marine biodiversity.
Droughts spread through the sub-tropics, accompanied by heatwaves and intense wildfires. Worst-hit are the Mediterranean, the south-west United States, southern Africa and Australia. -
2 °C to 3 °C
Summer heatwaves such as that in Europe in 2003, which killed 30,000 people, become annual events. Extreme heat sees temperatures reaching the low 40s Celsius in southern England.
Amazon rainforest crosses a "tipping point" where extreme heat and lower rainfall makes the forest unviable - much of it burns and is replaced by desert and savannah.
Dissolved CO2 turns the oceans increasingly acidic, destroying remaining coral reefs and wiping out many species of plankton which are the basis of the marine food chain. Several metres of sea level rise is now inevitable as the Greenland ice sheet disappears. -
3 °C to 4 °C
Glacier and snow-melt in the world's mountain chains depletes freshwater flows to downstream cities and agricultural land. Most affected are California, Peru, Pakistan and China. Global food production is under threat as key breadbaskets in Europe, Asia and the United States suffer drought, and heatwaves outstrip the tolerance of crops.
The Gulf Stream current declines significantly. Cooling in Europe is unlikely due to global warming, but oceanic changes alter weather patterns and lead to higher than average sea level rise in the eastern US and UK. -
4 °C to 5 °C
Another tipping point sees massive amounts of methane - a potent greenhouse gas - released by melting Siberian permafrost, further boosting global warming. Much human habitation in southern Europe, north Africa, the Middle East and other sub-tropical areas is rendered unviable due to excessive heat and drought. The focus of civilisation moves towards the poles, where temperatures remain cool enough for crops, and rainfall - albeit with severe floods - persists. All sea ice is gone from both poles; mountain glaciers are gone from the Andes, Alps and Rockies.
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5 °C to 6 °C
Global average temperatures are now hotter than for 50m years. The Arctic region sees temperatures rise much higher than average - up to 20C - meaning the entire Arctic is now ice-free all year round. Most of the topics, sub-tropics and even lower mid-latitudes are too hot to be inhabitable. Sea level rise is now sufficiently rapid that coastal cities across the world are largely abandoned.
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6 °C and Above
Danger of "runaway warming", perhaps spurred by release of oceanic methane hydrates. Could the surface of the Earth become like Venus, entirely uninhabitable? Most sea life is dead. Human refuges now confined entirely to highland areas and the polar regions. Human population is drastically reduced. Perhaps 90% of species become extinct, rivalling the worst mass extinctions in the Earth's 4.5 billion-year history.
Source: http://www.theguardian.com/environment/2009/apr/14/climate-change-environment-temperature
Heating Up: A Dangerous Spiral
This graphic, drawn up by Ed Hawkins, a climate scientist at the University of Reading in the United Kingdom, features a record of global temperatures spinning outward from the late 19th century to the present as the Earth heats up. The graphic displays monthly global temperature data, specifically how each month compares to the average for the same period from 1850-1900. At first, the years vacillate inward and outward, showing that a clear warming signal had yet to emerge from the natural fluctuations that happen from year to year. But clear warming trends are present in the early and late 20th century.
Can you determine about what year temperatures really started to rise?
So, the Earth's average temperature has increased about 1 degree Fahrenheit during the 20th century. What's the big deal?
One degree may sound like a small amount, but it's an unusual event in our planet's recent history. Small changes in temperature correspond to enormous changes in the environment. For example, at the end of the last ice age, when the Northeast United States was covered by more than 3,000 feet of ice, average temperatures were only 5 to 9 degrees cooler than today.
Now look at the spiral below, which shows simulated global temperature change from 1850 up to 2100 relative to the 1850 - 1900 average (how old will you be in the year 2100?). The temperature data are from Community Climate System (CCSM4) global climate model maintained by the National Center for Atmospheric Research. The simulation is for the IPCC Representative Concentration Pathway 8.5 (RCP8.5) emission scenario. RCP8.5 is the most aggressive scenario in which green house gases continue to rise unchecked through the end of the century, leading to an equivalent of about 1370 ppm CO2, which is roughly four times the concentration at present.
The Sixteen Hottest Years on Record
The chart above shows the global combined land and ocean temperature rank and how much the average temperature for that year departed from the average temperature for the period from 1880 to 2015. Note that of the 16 hottest years on record for that period have occurred in the last 17 years. The prediction of NASA and international climate scientists is for the trend to continue and even accelerate. For example, eighty years from now, the mean global temperature is expected to be 7 to 11 °F warmer than it is today.
Principle 8b
Arctic Sea and Lake Ice is Melting
Melting Ice
Rising temperatures across the U.S. have reduced lake ice, sea ice, glaciers, and seasonal snow cover over the last few decades. Mount Rainier’s glaciers are an example. The mountain's glaciers are the largest single-mountain glacier system in the contiguous 48 states. They represent 25% of the total ice area in the contiguous 48 states and contain as much ice (by volume) as all the other Cascade volcanoes combined. However, these glaciers shrank 22% by area and 25% by volume between 1913 and 1994 due to global warming. In the Great Lakes, total winter ice coverage has decreased by 63% since the early 1970s. This includes the entire period since satellite data became available. When the record is extended back to 1963 using pre-satellite data, the overall trend is less negative because the Great Lakes region experienced several extremely cold winters in the 1970s. Read more…
Source: National Climate Assessment
And watch this video
Melting Ice
Sea ice in the Arctic has also decreased dramatically since the late 1970s, particularly in summer and autumn. Since the satellite record began in 1978, minimum Arctic sea ice extent (which occurs in early to mid-September) has decreased by more than 40%. This decline is unprecedented in the historical record, and the reduction of ice volume and thickness is even greater. Ice thickness decreased by more than 50% from 1958-1976 to 2003-2008, and the percentage of the March ice cover made up of thicker ice (ice that has survived a summer melt season) decreased from 75% in the mid-1980s to 45% in 2011. Recent analyses indicate a decrease of 36% in autumn sea ice volume over the past decade. The 2012 sea ice minimum broke the preceding record (set in 2007) by more than 200,000 square miles.
Ice loss increases Arctic warming by replacing white, reflective ice with dark water that absorbs more energy from the sun. More open water can also increase snowfall over northern land areas and increase the north-south meanders of the jet stream, consistent with the occurrence of unusually cold and snowy winters at mid-latitudes in several recent years.
The loss of sea ice has been greater in summer than in winter. The Bering Sea, for example, has sea ice only in the winter-spring portion of the year, and shows no trend in surface area covered by ice over the past 30 years. However, seasonal ice in the Bering Sea and elsewhere in the Arctic is thin and susceptible to rapid melt during the following summer.
The seasonal pattern of observed loss of Arctic sea ice is generally consistent with simulations by global climate models, in which the extent of sea ice decreases more rapidly in summer than in winter. However, the models tend to underestimate the amount of decrease since 2007. Projections by these models indicate that the Arctic Ocean is expected to become essentially ice-free in summer before mid-century under scenarios that assume continued growth in global emissions, although sea ice would still form in winter. Models that best match historical trends project a nearly sea ice-free Arctic in summer by the 2030s, and extrapolation of the present observed trend suggests an even earlier ice-free Arctic in summer. However, even during a long-term decrease, occasional temporary increases in Arctic summer sea ice can be expected over timescales of a decade or so because of natural variability. The projected reduction of winter sea ice is only about 10% by 2030, indicating that the Arctic will shift to a more seasonal sea ice pattern. While this ice will be thinner, it will cover much of the same area now covered by sea ice in winter.
Source: National Climate Assessment
The Arctic is a Seriously Weird Place Right Now
- Published: November 21st, 2016
- Source: http://www.climatecentral.org/news/arctic-sea-ice-record-low-20903
By Brian Kahn
The sun set on the North Pole more than a month ago, not to rise again until spring. Usually that serves as a cue for sea ice to spread its frozen tentacles across the Arctic Ocean. But in the depths of the polar night, a strange thing started to happen in mid-October. Sea ice growth slowed to a crawl and even started shrinking for a bit.
Intense warmth in both the air and oceans is driving the mini-meltdown at a time when Arctic sea ice should be rapidly growing. This follows last winter, when temperatures saw a huge December spike.
Sea ice extent using JAXA satellite measurements.
Credit: Zack LabeEven in an age where climate change is making outliers — lowest maximum sea ice extent set two years in a row, the hottest year on record set three years in a row, global coral bleaching entering a third year — the norm, what’s happening in the Arctic right now stands out for just how outlandish it is.
“I’ve never seen anything like it this last year and half,” Mark Serreze, director of the National Snow and Ice Data Center, said.
The latest twist in the Arctic sea ice saga began in mid-October. Temperatures stayed stuck in their September range, pausing sea ice growth. By the end of the month, the Arctic was missing a chunk of ice the size of the eastern U.S.
| RELATED | Warm Temps Slow Arctic Sea Ice Growth to a Crawl |
The oddness continued into November. A large area of the Arctic saw temperatures as much as 36°F above normal, further slowing Arctic sea ice growth and even turning it around for a few days. In other words, it was so warm in the Arctic that despite the lack of sunlight, sea ice actually disappeared.
“ The ridiculously warm temperatures in the Arctic during October and November this year are off the charts over our 68 years of measurements,” Jennifer Francis, a climate scientist at Rutgers University who studies the Arctic, said.
Compounding the warm air is warm water. Sea surface temperatures on the edge of the ice are also running well above normal in many places, further inhibiting sea ice growth.
As a footnote, Antarctic sea ice is also record low, making for a really dire global sea ice graph. The two regions’ current conundrums aren’t connected, and researchers are still trying to untangle what’s happening there. But in the Arctic, a number of factors — both driven by climate change and weather patterns — are to blame for this year’s bizarre sea ice situation.
Global sea ice extent is also at a record low.
Credit: WipneusFirst, Arctic sea ice itself has some issues. Old ice has all but disappeared since record keeping began in the 1980s, and the majority of the ice pack is now young ice that tends to be more brittle and prone to breakup when extreme warmth strikes.
Some of that warmth came courtesy of the tropics where convection patterns created a series of large troughs and ridges in the atmosphere. The pattern that set up in mid-October put the eastern edge of one of these troughs over northeast Asia, according to Paul Roundy, an atmospheric scientist at the University of Albany.
Before
Drag split-screen slider or click on before/after link.
After
A comparison of the extension of older sea ice in the Arctic in September 1984 and September 2016.
Credit: NASA Earth Observatory
“The result has been a strong surface low that has funneled warm air at the surface across the Bering Strait,” he said. “A similar low set up in the wave train over the North Atlantic, providing another pathway for warmth into the Arctic.”
The ocean heat has roots in this summer, when dark open water absorbed the sun’s incoming energy (compared to white sea ice, which reflects it back into space). Francis said this “not only slowed the freezing process, but also warmed and moistened the air. That extra moisture is very important because water vapor is a greenhouse gas and it also tends to create more clouds — both of these effects help trap heat near the surface.” It’s what Serreze said was a “double whammy” of warming causing the current meltdown.
This all follows what was the second-lowest sea ice extent ever recorded in September and what has been a persistent dwindling of Arctic sea ice for decades on end as climate change cranks up the heat.
The Arctic is warming twice as fast as the rest of the planet and it’s possible that the region could see ice-free summers as early as the 2030s. If carbon pollution continues at its current pace, it would likely make ice-free summers the norm by mid-century.
Going forward, Serreze said research should focus as on how an already changing Arctic system responds to these types of shocks.
“A valuable way of viewing Arctic system now is (looking at) how it responds to these extremes. Has their impact changed now that Arctic has changed?” he said.
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Arctic Oceans, Sea Ice, and Coasts
The impacts of reduced sea ice include severe and coastal erosion, isolation for rural villages and reduced habitat for wildlife
Source: https://toolkit.climate.gov/topics/arctic/arctic-oceans-sea-ice-and-coasts
The Arctic Ocean is blanketed by seasonal sea ice that expands during the frigid Arctic winter, reaching a maximum average extent each March. Sea ice retreats during the Northern Hemisphere's summer, reaching its minimum extent for the year every September. Arctic ice cover plays an important role in maintaining Earth’s temperature—the shiny white ice reflects light and the net heat that the ocean would otherwise absorb, keeping the Northern Hemisphere cool.
Arctic sea ice extent in September 2012 was the lowest in the satellite record (since 1979). The magenta line indicates the September average ice extent from 1981 to 2010.
Arctic sea ice is declining at an increasing rate in all months of the year, with a stronger decline in summer months. Researchers who study climate and sea ice expect that, at some point, the Arctic Ocean will lose virtually all of its late summer ice cover. A robust range of evidence suggests that Arctic sea ice is declining due to climate warming related to the increased abundance of heat-trapping (greenhouse) gases in the atmosphere from human burning of coal, oil, and gas. Because greenhouse gases stay in the atmosphere for multiple decades, scientists do not expect any reversal in the downward trend in ice extent.
Despite year-to-year variations, satellite data show a decline of more than 13 percent per decade in September ice extent since the satellite record began in 1979. The satellite data are less comprehensive before 1979, but shipping records and other evidence show that the ice extent has been in a continued state of decline for at least the last one hundred years. Climate models have long predicted that summer sea ice would disappear as temperatures rose in the Arctic, but ice loss has occurred even faster than any models predicted. Researchers now expect that the Arctic Ocean will be virtually ice-free in summer well before the end of this century, perhaps as early as the 2030s.
Impacts of reduced sea ice
Arctic amplification refers to the magnified warming in the Arctic relative to the rest of the globe—the rate of warming in the Arctic is nearly two times the global average. While a number of mechanisms contribute to Arctic amplification, the loss of Arctic sea ice cover plays a dominant role due to the reduction in the net albedo—a measure of how well a surface reflects incoming solar energy.
In 2012, the Parry Channel—a portion of the long-sought Northwest Passage—went from ice-choked on July 17 (left) to open water on August 3 (right). Sea ice reflects most of the sunlight energy that hits it back into space; open water can absorb heat energy from the sun.
White or light-colored sea ice is very reflective, so its albedo is higher than that of ocean water. With the huge increase in the area of ice-free water compared to a decade ago, the ocean can absorb much more heat than it used to. This, in turn, means that more heat energy is available to be released back into the atmosphere in autumn as sunlight wanes. As ice cover shrinks, areas of open water absorb heat that the ice would have reflected. The water warms up, and before ice can form again in the fall the ocean must release some of that heat to the atmosphere. Scientists are concerned that this increased heat transfer to the atmosphere could magnify future climate warming trends.
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Principle 8c
Sea Level is Rising
Melting of ice sheets and glaciers, combined with the thermal expansion of seawater as the oceans warm, is causing sea level to rise. There is strong evidence that global sea level is now rising at an increased rate and will continue to rise during this century.
While studies show that sea levels changed little from AD 0 until 1900, sea levels began to climb in the 20th century.
The two major causes of global sea-level rise are thermal expansion caused by the warming of the oceans (since water expands as it warms) and the loss of land-based ice (such as glaciers and polar ice caps) due to increased melting. Read more…
Sea Level is Rising
Records and research show that sea level has been steadily rising at a rate of 0.04 to 0.1 inches per year since 1900. This rate may be increasing. Since 1992, new methods of satellite altimetry (the measurement of elevation or altitude) indicate a rate of rise of 0.12 inches per year. This is a significantly larger rate than the sea-level rise averaged over the last several thousand years.
Seawater is beginning to move onto low-lying land and to contaminate coastal fresh water sources and beginning to submerge coastal facilities and barrier islands. Sea-level rise increases the risk of damage to homes and buildings from storm surges such as those that accompany hurricanes.
For a good summary of climate change impacts on extreme weather events, visit the National Climate Assessment:
Sea level rise: Global warming's yardstick
By Rosalie Murphy,
NASA's Jet Propulsion Laboratory
Source: http://climate.nasa.gov/news/2201/
One of the Argo array’s buoys begins collecting ocean temperature data after a science team deploys it in the Atlantic Ocean. Credit: Argo / University of California, San Diego.
Global sea levels have been ticking steadily higher by about an eighth of an inch (3.2 millimeters) each year since scientists began measuring them two decades ago. That’s why Carmen Boening, a research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, was so shocked in 2010 and 2011, when she saw a quarter-inch (five-millimeter) drop in sea level – a sudden reversal of the trend.
“We knew that either the sea was cooling, or there was less water in the ocean,” Boening said. Like metal, water contracts when it cools. “So we used NASA’s GRACE mission, which basically weighs water to tell us how much is present in different parts of the world, both in the ocean and on land. We found there was actually less water in the ocean.”
Water can’t just vanish. If it leaves the ocean, it has to show up somewhere else in the water cycle. Sure enough, Boening’s team found huge amounts of precipitation and flooding in Australia and South America. GRACE data suggested lots of water had evaporated from the ocean during the 2011 La Niña event. Then other wind patterns pushed the precipitation to Australia.
“It had to be a combination of all these events at once, and that’s why the drop was so large,” Boening said. “But at some point, it had to run off into the ocean. That’s what happened next.” A few months later, the ocean returned to the previous year’s levels and the upward trend resumed.
How NASA measures sea level
Global sea levels have risen by about 8 inches in the last 130 years. It might not sound like much – but the ocean covers about 70 percent of Earth’s surface and holds about 99 percent of its water. A tiny rise or fall involves a lot of water.
“Sea level rise is the yardstick for global warming,” said Josh Willis, a research scientist at JPL. “It’s the ruler by which we measure how much human activity has changed the climate. It’s the sum of the extra heat the ocean has absorbed and the water that’s melted off of glaciers and ice sheets.” 
The Ocean Surface Topography Mission (OSTM)/Jason-2 measures sea surface height. Credit: NASA
Willis leads NASA’s Jason missions, satellites that measure sea level and ocean surface topography, or variations in ocean surface height at different areas around the globe. This variation is driven in part by deeper currents and weather patterns like El Niño, La Niña and the Pacific Decadal Oscillation. These patterns move huge amounts of water from some regions of the ocean to others, pushing some parts of the surface downward and others upward.
The GRACE twin satellites make detailed measurements of Earth's gravity field. Credit: NASA
The Gravity Recovery and Climate Experiment (GRACE) mission, which helped Boening and Willis track water during the 2011 La Niña, collects data using twin satellites orbiting Earth together. When the lead satellite encounters a slight change in Earth’s gravity, the force pulls it a little further from its partner. The second satellite measures the distance between them to estimate the strength of Earth’s gravity.
The planet’s gravity changes because different amounts of mass have piled up at different places. There’s a lot more Earth in the Himalaya, for example, than in the Mississippi Delta. Similarly, when water coalesces in a certain part of the ocean, it tugs on GRACE’s satellites a little harder.
But changes on land also play a role. For example, Greenland’s ice is melting. "As the land loses mass, its gravitational pull is not as strong, so it’s losing its ability to attract water,” Boening said. Though melting land ice from Greenland and glaciers account for about two-thirds of sea level rise to date, “sea level around Greenland is actually going down.”
Mass, height and heat
The ocean is also gaining heat. Small heat transfers happen constantly at the ocean’s surface and, eventually, the ocean swallows most of the heat greenhouse gases have trapped in Earth’s atmosphere. That heat warms the whole ocean, causing it to expand.
Expansion seems simple, but measuring it is a challenge. “Over 90 percent of the heat trapped inside Earth’s atmosphere by global warming is going into the oceans,” Willis said. Temperature data from 19th-century ship, compared to a set of 3,600 buoys measuring ocean temperature today, confirms that the ocean – especially its upper half – has warmed since 1870.
In the bottom half of the ocean, though, it’s harder to tell. Buoys measure only about halfway to the bottom, a depth of about 1.25 miles (2,000 meters). Over many decades, ocean currents pull water from the surface of the ocean toward its depths. Scientists have assumed the deep ocean has been warming, too – but a new paper by Willis and other JPL scientists found no detectable warming below that 1.25-mile (2,000-meter) mark since 2005.
“We can’t see heat in the deep ocean yet. The effect has been too small over our ten years of data, and the ways the ocean can get heat down deep are very slow. It might take a hundred years,” Willis said. “We still have to rely on the data and not our simulations to figure out what’s going on in the deep ocean. So we have some more scientific work to do.”
On the other hand, another paper from the same journal found that earlier studies drastically underestimated warming in the Southern Ocean, since the 1970s. New estimates suggest it absorbed anywhere from 25 to 58 percent more heat than previous researchers thought.
Scientists will continue learning more about the ocean’s intricacies, correcting assumptions and revising old estimates. But Willis warns against losing sight of the strong global trend toward rising sea levels.
“The picture is very simple,” he said. “The ocean heats up and causes sea level rise. Ice melts and causes sea level rise. We can see the results at the shoreline.”
This feature is part of a series exploring how NASA monitors Earth’s water cycle. Other ocean missions include Aquarius, which measures the ocean’s salinity to offer scientists clues about evaporation and rainfall patterns and changes in the ocean’s density, which can drive circulation patterns. The Surface Water and Ocean Topography (SWOT) mission will improve topography measurements at the coast after its 2020 launch. Learn more about all of NASA’s Earth science missions.
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Visualizing Our Changing Coastlines
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See how rising sea levels will affect North America's coast under different global warming conditions. You can type in any coastal location you may be interested in.
Be sure to scroll down in the window below to learn more.
Principle 8d
Changing precipitation and temperature are altering the distribution and availability of water
Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions will alter the distribution and availability of freshwater resources, reducing reliable access to water for many people and their crops. Winter snowpack and mountain glaciers that provide water for human use are declining as a result of global warming. There are many unknowns in terms of how ecosystems and societies will be impacted by the loss of snow and ice which serve as reservoirs of freshwater.
Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions will alter the distribution and availability of freshwater resources, reducing reliable access to water for many people and their crops. Read more…
Changing precipitation and temperature are altering the distribution and availability of water
Winter snowpack and mountain glaciers that provide water for human use are declining as a result of global warming. There are many unknowns in terms of how ecosystems and societies will be impacted by the loss of snow and ice which serve as reservoirs of freshwater.
Runoff patterns may shift in many parts of the world with more rain and less snow falling as precipitation. While billions of people depend on runoff from rivers that originate in the Himalayan Glaciers, much of the water in the rivers is from monsoon rains, not snow and ice, so the problem may not be as dire is it might first appear.
See maps predicting trends and changes
Projected change in watershed basin type by the 2040s (2030–2059). The Plateau Region is contained in the yellow circle. Basin types are defined by the ratio of April 1 snow water equivalent (SWE) to cool season (October through March) precipitation, which represents most precipitation falling as snow or rain. The map at the top shows our watersheds as they have been historically, and the three maps at the bottom show how our watersheds will change under different model predictions: one with the least amount of warming and drier conditions, one with moderate warming, and one with the most warming and wetter conditions.
Good summaries of impacts on freshwater
Despite Gains, Western Snowpack Trending Downward
Western Snowpack Trending Downward
By Climate Central
The first of April is the end of the wet season across the West, the time of year when the region gets most of its precipitation. As such, it is a good time to take inventory of the snowpack in the mountains. The snow readings are important during this time of the year, as several locations depend on the meltwater from that snowpack for drinking water and irrigation through the drier and hotter summer months. It also serves as a long-term measurement, as in a warming world, the spring snowpack will melt more quickly as summer nears.
While the western snowpack levels have improved over last year’s dismally low levels overall, there are still places below average in Colorado, Montana, and New Mexico.
More Rain, Less Snow
The Plateau Region - A Region at Risk
- The Pacific Northwest and the Plateau Region have been the hardest hit, with low elevation snow on a clear path toward oblivion: 81 and 91 percent of stations under 2,000 feet in Washington and Oregon, respectively, show a trend toward a lower percentage of winter precipitation falling as snow over the 65 years analyzed.
- At 2,000 to 5,000 feet in Washington and Oregon the effect is similar, with 63 and 77 percent of stations recording lower percentage of precipitation falling as snow during the winter snow season, over the period analyzed. In the interior Northwest, Montana and Idaho showed the same basic trend between 2,000 to 5,000 feet, with 64 and 82 percent of stations reporting a shift to more rain as a higher percentage of precipitation than snow.
- At higher elevations in Montana and Idaho, the shift was equally strong, with 75 and 78 percent of stations reporting a decrease in the percentage of precipitation falling as snow at 5,000 to 8,000 feet. Oregon has only one station above 5,000 feet, but it too reported a strong increase.
Learn about projected impacts on Montana’s farm economy
Farm report: Montana to lose millions to climate change
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Montana agriculture losses to climate change could total $736 million a year, estimates an economic study prepared for Montana Farmers Union.
Warmer temperatures and drier summers are withering the future of Montana spring wheat, a major cash crop for state farmers, according to the report released Wednesday.
Over time, those changing conditions will cost the state $372 million on labor earnings due to 12,167 jobs lost to declined production. Range land losses due to dry conditions and changing plant life, will cut labor earnings related to cattle production by $364 million, and job losses similar to those for grain.
“As far as most of us are concerned, it’s already happening and we’re trying to figure out how to make money with what’s already happening and stay in business,” said Erik Somerfeld, and MFU member who farms in the Golden Triangle of north central Montana.
Somerfeld, who is also a member of the policy committee for the National Farmers Union, said spring wheat has become more difficult to raise in his area because of weeds and poor summer moisture.
The report was researched by former UM economist Thomas Power and his son, Donovan, a geologist. The two published a report in late 2015 projecting 11,000 job losses in Montana's outdoor economy because of climate change. In 28 pages, the two outline the consequences of warmer daily low temperatures in the winter, as well as an increasing number of days with high temperatures of 95 degrees or warmer.
The study concludes that annual precipitation will actually increase from now to 2055, but more of that moisture will be rain, reducing winter snowpack and shortening the irrigation season. The climate forecasts are based on research by Third National Climate Assessment by the U.S. Global Change Research Program.
The assessment projects a 4 to 5 degree increase in Montana temperatures by 2055, including a decrease in the number of days when the temperature drops below 10 degrees. It also forecasts that there will be 20 fewer days a year where temperatures drop below freezing.
Conversely, the number of days above 95 degrees could increase by 5 days, or as many as 15.
Power said the lost earned income from climate change included not only jobs directly tied to farming and ranching, but also service tied to businesses providing services to agriculture businesses. Agriculture is one seventh of Montana’s economy, and one of the largest non-government sectors.
Montana Farmers Union has been progressively advancing discussions on climate change since early 2015, when it collaborated on town hall meetings with Montana State University researchers and the state Department of Agriculture.
The group headquartered in Great Falls, has been cautioning farmers that planting seasons are already changing due to climate change, with earlier spring plantings, as well as a shift to fall-planted winter wheat as farmers try to avoid growing crops in summer conditions that are more hot and dry.
Principle 8e
Extreme Weather Events are Increasing
Incidents of extreme weather are projected to increase as a result of climate change—indeed they already have increased and are projected to increase much more. Many locations will see a substantial increase in the number of heat waves they experience per year and a decrease in episodes of severe cold. Precipitation events are expected to become less frequent but more intense in many areas, and droughts will be more frequent and severe in areas where average precipitation is projected to decrease. Explore the graphics on this page to see how things have already changed.
Move through the slides below to see how weather is becoming more extreme through the seasons
For a good summary of climate change impacts on extreme weather events, visit the National Climate Assessment:
For a great interactive on billion dollar climate disasters with maps, statistics, timelines, and more visit this NOAA site:
Risk of Extreme Weather From Climate Change to Rise Over Next Century, Report Says
By SABRINA TAVERNISEJUNE 22, 2015
Source: http://www.nytimes.com/2015/06/23/science/risk-of-extreme-weather-from-climate-change-to-rise-over-next-century-report-says.html
Drought in Puerto Rico has left the La Plata reservoir nearly empty. A study in The Lancet predicts a growing number of people will be affected by extreme weather over the next century.
Credit
Alvin Baez/Reuters
WASHINGTON — More people will be exposed to floods, droughts, heat waves and other extreme weather associated with climate change over the next century than previously thought, according to a new report in the British medical journal The Lancet.
The report, published online Monday, analyzes the health effects of recent episodes of severe weather that scientists have linked to climate change. It provides estimates of the number of people who are likely to experience the effects of climate change in coming decades, based on projections of population and demographic changes.
The report estimates that the exposure of people to extreme rainfall will more than quadruple and the exposure of people to drought will triple compared to the 1990s. In the same time span, the exposure of the older people to heat waves is expected to go up by a factor of 12, according to Peter Cox, one of the authors, who is a professor of climate-system dynamics at the University of Exeter in Britain.
Climate projections typically are expressed as averages over large areas, including vast expanses, like oceans, where people do not live. The report calculates the risk to people by overlaying areas of the highest risk for climate events with expected human population increases. It also takes into account aging populations — for example, heat waves pose a greater health risk to old people.
Men in Pakistan cool themselves in a river near Islamabad during a heatwave. The Lancet study is part of an effort to look at how climate might change life on earth for people.
Credit
Aamir Qureshi/Agence France-Presse — Getty Images
The report is part of a series of efforts to analyze how climate change might affect human health. Other major climate reports, the Intergovernmental Panel on Climate Change, a global document, and the National Climate Assessment in the United States, have addressed the issue. But Professor Cox said the new report was the first large-scale effort to quantify the effects that different types of extreme weather would have on people.
“We are saying, let’s look at climate change from the perspective of what people are going to experience, rather than as averages across the globe,” he said. “We have to move away from thinking of this as a problem in atmospheric physics. It is a problem for people.”
The Lancet first convened scientists on the topic in 2009, and produced a report that declared climate change was “the biggest global health threat of the 21st century.” Monday’s report notes that global carbon emission rates have risen above the worst-case scenarios used in 2009, and that in the absence of any major international agreement on cutting those rates, projections of mortality and illness and other effects, like famine, have worsened.
“Everything that was predicted in 2009 is already happening,” said Nick Watts, a public health expert at the Institute for Global Health at University College London, who led the team of more than 40 scientists from Europe, Africa and China that produced the report. “Now we need to take a further step forward. The science has substantially moved on.”
For years, climate change was presented in terms of natural habitats and the environment, but more recently, experts have been looking at how it might change life on earth for people. Scientists and some governments are trying to frame the dangers of climate change in health terms in order to persuade people that the topic is urgent, not simply a distant matter for scientists. Governments around the world are preparing for a United Nations summit meeting on climate change in Paris in December to discuss new policies to limit greenhouse-gas emissions.
The report measures the increase over time in “exposure events,” which it defines as the number of times people experience any given extreme weather event.
By the end of the century, the report estimates, the exposure to heat waves each year for older people around the world is expected to be around 3 billion more cases than in 1990. The number of times people of all ages are exposed to drought would increase by more than a billion a year. The rise in exposures to extreme rain would be around 2 billion a year by the end of the century, in part because populations are growing.
Even without climate change, the health problems that come along with economic development are significant, the authors note. About 1.2 million people died from illnesses related to air pollution in China in 2010, the report said.
Most broad climate reports do not go further than explaining the science, but much of the Lancet report is dedicated to policy prescriptions to slow or stop climate change and mute its effects on health. It notes that using fewer fossil fuels “is no longer primarily a technical or economic question — it is now a political one,” and urges governments to enact changes that would accomplish that.
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Principle 8f
Oceans are becoming more acidic
The chemistry of ocean water is changed by absorption of carbon dioxide from the atmosphere. Increasing carbon dioxide levels in the atmosphere is causing ocean water to become more acidic, threatening the survival of shell-building marine species and the entire food web of which they are a part.
The oceans are not, in fact, acidic, but slightly basic. Acidity is measured using the pH scale, where 7.0 is defined as neutral, with higher levels called "basic" and lower levels called "acidic". Historical global mean seawater values are approximately 8.16 on this scale, making them slightly basic. To put this in perspective, pure water has a pH of 7.0 (neutral), whereas household bleach has a pH of 12 (highly basic) and battery acid has a pH of zero (highly acidic). Read More…
Oceans are becoming more acidic
The chemistry of ocean water is changed by absorption of carbon dioxide from the atmosphere. Increasing carbon dioxide levels in the atmosphere is causing ocean water to become more acidic, threatening the survival of shell-building marine species and the entire food web of which they are a part.
The oceans are not, in fact, acidic, but slightly basic. Acidity is measured using the pH scale, where 7.0 is defined as neutral, with higher levels called "basic" and lower levels called "acidic". Historical global mean seawater values are approximately 8.16 on this scale, making them slightly basic. To put this in perspective, pure water has a pH of 7.0 (neutral), whereas household bleach has a pH of 12 (highly basic) and battery acid has a pH of zero (highly acidic).
By the end of this century, if concentrations of CO2 continue to rise at current rates, we may expect to see changes in pH that are three times greater and 100 times faster than those experienced during the transitions from glacial to interglacial periods. Such large changes in ocean pH have probably not been experienced on the planet for the past 21 million years.
However, even a small change in pH may lead to large changes in ocean chemistry and ecosystem functioning. Over the past 300 million years, global mean ocean pH values have probably never been more than 0.6 units lower than today. Ocean ecosystems have thus evolved over time in a very stable pH environment, and it is unknown if they can adapt to such large and rapid changes. Based on the emissions scenarios of the Intergovernmental Panel on Climate Change and general circulation models, we may expect a drop in ocean pH of about 0.4 pH units by the end of this century, and a 60% decrease in the concentration of calcium carbonate, the basic building block for the shells of many marine organisms.
For a good summary of climate change impacts on ocean acidification, visit the National Climate Assessment:
It's Not Just Acidification that's Harming the Oceans: Two Other Major Effects of Climate Change on the Earth's Oceans
Oceans are heating up too. Learn how ocean temperatures have changed over the past century:
Climate change may be choking the ocean’s oxygen supply too. Learn about the results of an indepth study of dissolved oxygen in the Earth's oceans since 1958.
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Principle 8g
Ecosystems are changing
Ecosystems on land and in the ocean have been and will continue to be disturbed by climate change. Animals, plants, bacteria, and viruses will migrate to new areas with favorable climate conditions. Infectious diseases and certain species will be able to invade areas that they did not previously inhabit.
In recent years, millions of pinyon pine trees in the American Southwest have died due to drought and high heat. Global climate models predict persistent drought for the American Southwest under current rates of change. They also project changes of similar magnitude to many other ecosystems across the western US and across the globe.
Read more…
Ecosystems are changing
Ecosystems on land and in the ocean have been and will continue to be disturbed by climate change. Animals, plants, bacteria, and viruses will migrate to new areas with favorable climate conditions. Infectious diseases and certain species will be able to invade areas that they did not previously inhabit.
In recent years, millions of pinyon pine trees in the American Southwest have died due to drought and high heat. Global climate models predict persistent drought for the American Southwest under current rates of change. They also project changes of similar magnitude to many other ecosystems across the western US and across the globe.
In the Pacific Northwest (including western Montana), the current warming trend is expected to continue, with average warming of 2.1 °C (3.78 °F) by the 2040s and 3.8 °C (6.84 °F) by the 2080s; precipitation may vary slightly, but the magnitude and direction are uncertain.
This warming will have far-reaching effects on aquatic and terrestrial ecosystems in the Pacific Northwest and western Montana.
Hydrologic systems will be especially vulnerable as watersheds become increasingly rain dominated, rather than snow dominated, resulting in more autumn/winter flooding, higher peak flows, and lower summer flows. It will also greatly reduce suitable fish habitat, especially as stream temperatures increase above critical thresholds. In forest ecosystems, higher temperatures will increase stress and lower the growth and productivity of lower elevation tree species. Distribution and abundance of plant species may change over the long term, and increased disturbance (wildfire, insects, and invasive species) will cause rapid changes in ecosystem structure and function across broad landscapes. This in turn will alter habitat for a wide range of animal species by potentially reducing connectivity and late successional forest structure.
Coping with and adapting to the effects of an altered climate will become increasingly difficult after the mid-21st century, although adaptation strategies and tactics are available to ease the transition to a warmer climate. For roads and infrastructure, tactics for increasing resistance and resilience to higher peak flows include installing hardened stream crossings, stabilizing streambanks, designing culverts for projected peak flows, and upgrading bridges and increasing their height. For fisheries, tactics for increasing resilience of native trout to altered hydrology and higher stream temperature include restoring stream and floodplain complexity, reducing road density near streams, increasing forest cover to retain snow and decrease snow melt, and identifying and protecting cold-water refugia. For vegetation, tactics for increasing resilience to higher temperature and increased disturbance include accelerating development of late-successional forest conditions by reducing density and diversifying forest structure, managing for future range of variability in structure and species, including invasive species prevention strategies in all projects, and monitoring changes in tree distribution and establishment at tree line. For wildlife, tactics for increasing resilience to altered habitat include increasing diversity of age classes and restoring a patch mosaic, increasing fuel reduction treatments in dry forests, using conservation easements to maintain habitat connectivity, and removing exotic fish species to protect amphibian populations.
Hotter Years, More Fires
To understand wildfire trends, Climate Central analyzed 45 years of U.S. Forest Service records of large wildfires (those fires burning more than 1,000 acres) from the western U.S. in our new report, Western Wildfires: A Fiery Future. They found that the average number of large wildfires burning each year and the total area burning in these fires have both increased dramatically since the 1970s, as you can see in the graphics below.
More fires are burning across the U.S.
More acres are burning across the U.S.
Wildfire Tracker
Hover over a red circle to see how much area has been burned. Click on it, and you’ll get more climate context and the number of people at risk. No wildfire happens in a vacuum anymore. Large wildfires — those greater than 1,000 acres — have doubled since 1970 due in part to a warming climate. And with more people living in harm’s way, that’s raising the risk of losing life and property.
For a good summaries of climate change impacts on tribes, the Northwest, and aquatic ecosystems in the Rockies, explore these publications:
Climate Impacts on Ecosystems
Source: http://www.epa.gov/climatechange/impacts-adaptation/ecosystems.html
Climate is an important environmental influence on ecosystems. Climate changes and the impacts of climate change affect ecosystems in a variety of ways. For instance, warming could force species to migrate to higher latitudes or higher elevations where temperatures are more conducive to their survival. Similarly, as sea level rises, saltwater intrusion into a freshwater system may force some key species to relocate or die, thus removing predators or prey that were critical in the existing food chain.
Climate change not only affects ecosystems and species directly, it also interacts with other human stressors such as development. Although some stressors cause only minor impacts when acting alone, their cumulative impact may lead to dramatic ecological changes. [1] For instance, climate change may exacerbate the stress that land development places on fragile coastal areas. Additionally, recently logged forested areas may become vulnerable to erosion if climate change leads to increases in heavy rain storms.
Changes in the Timing of Seasonal Life-Cycle Events
For many species, the climate where they live or spend part of the year influences key stages of their annual life cycle, such as migration, blooming, and mating. As the climate has warmed in recent decades, the timing of these events has changed in some parts of the country. Some examples are:
- Warmer springs have led to earlier nesting for 28 migratory bird species on the East Coast of the United States. [1]
- Northeastern birds that winter in the southern United States are returning north in the spring 13 days earlier than they did in the early 20th century. [4]
- In a California study, 16 out of 23 butterfly species shifted their migration timing and arrived earlier. [4]
Range Shifts
As temperatures increase, the habitat ranges of many North American species are moving northward in latitude and upward in elevation. While this means a range expansion for some species, for others it means a range reduction or a movement into less hospitable habitat or increased competition. Some species have nowhere to go because they are already at the northern or upper limit of their habitat.
For example, boreal forests are invading tundra, reducing habitat for the many unique species that depend on the tundra ecosystem, such as caribou, arctic fox, and snowy owl. Other observed changes in the United States include expanding oak-hickory forests, contracting maple-beech forests, and disappearing spruce-fir forests. As rivers and streams warm, warmwater fish are expanding into areas previously inhabited by coldwater species. [5] Coldwater fish, including many highly valued trout species, are losing their habitats. As waters warm, the area of feasible, cooler habitats to which species can migrate is reduced. [5] Range shifts disturb the current state of the ecosystem and can limit opportunities for fishing and hunting.
See the Agriculture and Food Supply Impacts & Adaptation page for information about how habitats of marine species have shifted northward as waters have warmed.
Food Web Disruptions
The Arctic food web is complex. The loss of sea ice can ultimately affect the entire food web, from algae and plankton to fish to mammals. Source: NOAA (2011)
The impact of climate change on a particular species can ripple through a food web and affect a wide range of other organisms. For example, the figure shows the complex nature of the food web for polar bears. Declines in the duration and extent of sea ice in the Arctic leads to declines in the abundance of ice algae, which thrive in nutrient-rich pockets in the ice. These algae are eaten by zooplankton, which are in turn eaten by Arctic cod, an important food source for many marine mammals, including seals. Seals are eaten by polar bears. Hence, declines in ice algae can contribute to declines in polar bear populations. [4] [5] [6]
Threshold Effects
In some cases, ecosystem change occurs rapidly and irreversibly because a threshold, or "tipping point," is passed.
One area of concern for thresholds is the Prairie Pothole Region in the north-central part of the United States. This ecosystem is a vast area of small, shallow lakes, known as "prairie potholes" or "playa lakes." These wetlands provide essential breeding habitat for most North American waterfowl species. The pothole region has experienced temporary droughts in the past. However, a permanently warmer, drier future may lead to a threshold change—a dramatic drop in the prairie potholes that host waterfowl populations and provide highly valued hunting and wildlife viewing opportunities. [3]
Similarly, when coral reefs become stressed, they expel microorganisms that live within their tissues and are essential to their health. This is known as coral bleaching. As ocean temperatures warm and the acidity of the ocean increases, bleaching and coral die-offs are likely to become more frequent. Chronically stressed coral reefs are less likely to recover.
Pathogens, Parasites, and Disease
Climate change and shifts in ecological conditions could support the spread of pathogens, parasites, and diseases, with potentially serious effects on human health, agriculture, and fisheries. For example, the oyster parasite, Perkinsus marinus, is capable of causing large oyster die-offs. This parasite has extended its range northward from Chesapeake Bay to Maine, a 310-mile expansion tied to above-average winter temperatures. [8] For more information about climate change impacts on agriculture, visit the Agriculture and Food Supply Impacts & Adaptation page. To learn more about climate change impacts on human health, visit the Health Impacts & Adaptation page.
Extinction Risks
Climate change, along with habitat destruction and pollution, is one of the important stressors that can contribute to species extinction. The IPCC estimates that 20-30% of the plant and animal species evaluated so far in climate change studies are at risk of extinction if temperatures reach levels projected to occur by the end of this century. [1] Projected rates of species extinctions are 10 times greater than recently observed global average rates and 10,000 times greater than rates observed in the distant past (as recorded in fossils). [2] Examples of species that are particularly climate sensitive and could be at risk of significant losses include animals that are adapted to mountain environments, such as the pika, animals that are dependent on sea ice habitats, such as ringed seals, and cold-water fish, such as salmon in the Pacific Northwest. [5]
For information about how communities are adapting to the impacts of climate change on ecosystems, visit the Ecosystems Adaptation section.
References
1. Fischlin, A., G.F. Midgley, J.T. Price, R. Leemans, B. Gopal, C. Turley, M.D.A. Rounsevell, O.P. Dube, J. Tarazona, A.A. Velichko (2007). Ecosystems, their Properties, Goods, and Services. In: Climate Change 2007: Impacts, Adaptation and Vulnerability . Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Parry, M.L., O.F. Canziani, J.P. Palutikof, P.J. van der Linden, and C.E. Hanson (eds.). Cambridge University Press, Cambridge, United Kingdom.
2. Millennium Ecosystem Assessment (2005). Ecosystems and Human Well-Being: Biodiversity Synthesis (PDF). World Resources Institute, Washington, DC, USA.
3. CCSP (2009). Thresholds of Climate Change in Ecosystems . A report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Fagre, D.B., Charles, C.W., Allen, C.D., Birkeland, C., Chapin, F.S. III, Groffman, P.M., Guntenspergen, G.R., Knapp, A.K., McGuire, A.D., Mulholland, P.J., Peters, D.P.C., Roby, D.D., and Sugihara, G. U.S. Geological Survey, Department of the Interior, Washington DC, USA.
4. CCSP (2008). The Effects of Climate Change on Agriculture, Land Resources, Water Resources, and Biodiversity in the United States . A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Backlund, P., A. Janetos, D. Schimel, J. Hatfield, K. Boote, P. Fay, L. Hahn, C. Izaurralde, B.A. Kimball, T. Mader, J. Morgan, D. Ort, W. Polley, A. Thomson, D. Wolfe, M. Ryan, S. Archer, R. Birdsey, C. Dahm, L. Heath, J. Hicke, D. Hollinger, T. Huxman, G. Okin, R. Oren, J. Randerson, W. Schlesinger, D. Lettenmaier, D. Major, L. Poff, S. Running, L. Hansen, D. Inouye, B.P. Kelly, L Meyerson, B. Peterson, and R. Shaw. U.S. Environmental Protection Agency, Washington, DC, USA.
5. USGCRP (2009). Global Climate Change Impacts in the United States . Karl, T.R., J.M. Melillo, and T.C. Peterson (eds.). United States Global Change Research Program. Cambridge University Press, New York, NY, USA.
6. ACIA (2004). Impacts of a Warming Arctic: Arctic Climate Impact Assessment . Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, United Kingdom.
7. NRC (2008). Understanding and Responding to Climate Change: Highlights of National Academies Reports . National Research Council. The National Academies Press, Washington, DC, USA.
8. NRC (2008). Ecological Impacts of Climate Change . National Research Council. The National Academy Press, Washington, DC, USA.
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The Rapid and Startling Decline
Of World’s Vast Boreal Forests
Source: http://e360.yale.edu/feature/the_rapid_and_startling_decline_of_worlds_vast_boreal_forests/2919/
Scientists are becoming increasingly concerned about the fate of the huge boreal forest that spans from Scandinavia to northern Canada. Unprecedented warming in the region is jeopardizing the future of a critical ecosystem that makes up nearly a third of the earth’s forest cover.
by jim robbins
The boreal forest wraps around the globe at the top of the Northern Hemisphere in North America and Eurasia. Also known as taiga or snow forest, this landscape is characterized by its long, cold and snowy winters. In North America it extends from the Arctic Circle of northern Canada and Alaska down into the very northern tip of the United States in Idaho, Washington, Montana, and Minnesota. It's the planet's single largest biome and makes up 30 percent of the globe's forest cover.
Moose are the largest ungulate in the boreal, adapted with their long legs to wade in its abundant marshes, lakes and rivers eating willows, aspen and other plants. In the southern boreal forest of northern Minnesota, moose were once plentiful, but their population has plummeted. Thirty years ago, in the northwest part of the state, there were some 4,000; they now number about a hundred. In the northeast part, they have dropped from almost 9,000 to 4,300. They’ve fallen so far, so fast that some groups want them listed as endangered in the Midwest.
Hare and Ritchie, 1972
The boreal forest extends around the earth at the top of the Northern Hemisphere.
Moose carcasses deteriorate rapidly before they are found, and so forensics has not been able to determine why they are dying. Some experts surmise it could be that tens of thousands of ticks that mob an animal and weaken it. Others think it's a parasite called liver flukes, or the fact that winters have gotten so warm the animals can't regulate their body temperature and die from heat stress.
But Dennis Murray, a professor of ecology at Trent University in Peterborough, Ontario, thinks the dying moose of Minnesota and New Hampshire and elsewhere are one symptom of something far bigger – a giant forest ecosystem that is rapidly shrinking, dying, and otherwise changing. "The boreal forest is breaking apart," he says. "The question is what will replace it?"
Many scientists, in fact, are deeply concerned about the state of the world’s largest forest. The Arctic and the boreal region are warming twice as fast as other parts of the world. Permafrost is thawing and even burning, fires are burning unprecedented acres of forest, and insect outbreaks have gobbled up increasing numbers of trees. Climate zones are moving north ten times faster than forests can migrate. And this comes on top of increased industrial development of the boreal, from logging to oil and gas. The same phenomena are seen in Russia, Scandanavia, and Finland.
These disturbing signals of a forest in steep decline are why NASA just launched a large-scale research project called ABoVE — Arctic Boreal Vulnerability Experiment, a “major field campaign” with 21 field projects
over the next decade. But the studies will confirm in detail what many know is well underway.
“Boreal forests have a potential to hit a tipping point this century,” said Anatoly Shvidenko, of the International Institute for Applied Systems Analysis and a co-author of a survey of a recent research on boreal forests in the journal Science. “It is urgent we place more focus on climate mitigation and adaptation with respect to these forests.”
A tipping point would include the mother of all concerns: the unbridled melting of permafrost, one of the main thrusts of the ABoVE project. The permafrost in the boreal is more susceptible to thawing than in the Arctic because it’s closer to the freezing point. If large-scale melting occurs it would release more carbon dioxide and methane, which have been bound up in the frozen soil for thousands of years, and bring on more warming, and then more thawing, a dangerous loop. “Scientists call it a positive feedback, but most people call that a vicious cycle,” said Peter Griffith, chief support scientist for the ABoVE project.
Murray has been researching the boreal forest for 25 years, and he and his colleagues have seen many changes firsthand. In British Columbia, 80 percent of the province's mature lodgepole, another boreal species, have recently died from the mountain pine beetle, whose range and season both expanded greatly because of a warmer world. White and black spruce, the main trees species in the boreal, are also dying in vast numbers “The southwest Yukon looks dramatically different than it did 25 years ago when I did my master’s [degree],” he said. “Everywhere you go there is deadfall.”
NOAA
White spruce, shown above near the Denali Highway in Alaska, have been dying off in the boreal forest.
NASA has also seen a lot of forest browning in its studies, large swaths of forests with reduced growth that turn brown in the hotter than normal summers, and which contribute to much bigger and hotter fires and the thawing of the permafrost. “Severe fires burn a foot or more of organic soil and that's the insulating layer that keeps the permafrost frozen,” said Scott Goetz, lead scientist on the ABoVE project. “Once that is removed the thaw is much more rapid.”
The fires also change the vegetation. “When you remove that organic soil you get deciduous re-growth that lasts for decades,” said Goetz. “Maybe it will never come back as coniferous.”
Typically, when black spruce dies, it is replaced with new black spruce. “That’s been going on for a long, long time, [but] not anymore,” Murray says. “You lose spruce and you lose everything that lives in spruce and that is basically everything in the boreal forest. We’re seeing the same phenomena that we’ve seen with moose with lynx and snowshoe hares. And caribou are going belly up very, very fast. Their ranges are receding northward rapidly.”
The boreal is also home to some 5 billion birds. Many species have shifted their ranges north. “Climate change is having an impact much more quickly than we thought,” said Jeff Wells, a senior scientist with the International Boreal Campaign who focuses on birds. “Shifts that researchers thought would take place over 50 or a hundred years have taken place over a decade.”
But the changes in such a large system are complex. The forest isn’t merely receding north, it’s dying in some places in its interior and surviving quite well in others. A 2015 study found that while boreal spruce forest in interior Alaska is dying out because of warm temperatures, the same forest on the state’s west coast is thriving.
The dying spruce and moose and lynx and other changes are the dots that scientists are trying to connect to get a sense of what the boreal forest in North America will look like in the next half century.
The caveat is that in a system this massive and complex there are so many variables it's difficult to forecast with much certainty. The projected changes, for example, are based on the Intergovernmental Panel on Climate Change's temperature forecast of a rise of some 10 degrees by 2100. Should things warm faster or go higher, the changes could come faster and be deeper or different than modeled. And many changes could simply be unpredictable.
Murray’s modeling shows that a large gap is opening in the boreal in Ontario and Quebec, a gap some 500 by 350 kilometers. It will essentially split the contiguous forest into two separate forests — one to the east, the other to the west — as the black spruce and white spruce disappear. That gap could then become grassland or Carolinian, the forest ecosystem that dominates south of the boreal in Ontario, characterized by oak, maple, black walnut and other deciduous species.
As the spruce goes, so goes its inhabitants. "We're predicting there’s going to be no lynx, moose, or hare in central Ontario in the years to come,” Murray says, “so we’re going to have disjunct populations on either side." It could cause a break between populations of species and a loss of genetic diversity.
Murray has coined a term for the patchy quality of the effects of warming on the boreal – climate fragmentation. “Because it’s a gradual transition, it won’t be real boreal and it won’t be real deciduous,” says Murray. “Ecosystems will likely be less stable and more open to invasives.”
Changes in snow cover are already driving changes. In some places snow covers the ground for shorter periods, and the conditions of the snow are also changing. Instead of three feet of fluffy snow all winter, temperatures rise and melt the snow and then get cold and freeze it and compact it into ice, again and again. In such conditions, lynx, which have thick, padded paws that serve as de facto snowshoes and allow them to hunt atop deep snow, loses it evolutionary advantage. “It affects their ability to survive,” says Murray. “Coyotes, on the other hand, are extremely plastic and flexible. They weren't in the boreal a hundred years ago, but they are there now. They aren't everywhere, because they don’t do well in deep snow, but that's changing.” They are competing with lynx by foraging for their kills and preying on hares and squirrels.
The die-off of much of the boreal forest could have serious and unpredictable repercussions on the global climate system. When British Columbia’s lodgepole forests died, the province went from being a carbon sink to a carbon source because the dead forests released massive amounts of stored CO2. If the spruce forests of the boreal disappear they could also alter climate systems by releasing CO2. Because they are dark, they also absorb heat, but a treeless, snow-covered landscape would reflect far more solar energy back into the atmosphere.
Knowing what could happen in the next 50 or 60 years, and where, is important for conservation and other strategies. The boreal, especially in Canada, isn’t just a forest. It’s woven into the fabric of the region’s life and culture. Hundreds of First Nations call the boreal home, and they depend on it for sustenance, hunting moose and caribou, picking berries, and fishing. Paper and lumber industries also depend on a healthy boreal.
The research NASA is doing will be used to help determine how communities and land managers in the boreal might adapt to changes. Dall sheep in the Yukon, for example, are in decline and a subject of one of NASA's studies. The results will be given to provincial and federal officials in Canada to make decisions on issues ranging from hunting to access to land management.
Meanwhile, in the hope of slowing the thawing of boreal permafrost, the International Boreal Conservation Campaign has launched a “cold carbon storage campaign.” This initiative is aimed at managing the boreal in ways that keep as much as possible frozen — no road building atop it, for example, or the creation of new large scale carbon reserves.
But such measures can only do so much. The real decisions on the fate of the boreal are up to the world community. It’s not a good sign that when I contacted Canadian Forest Service scientist Sylvie Gauthier, the lead author of the Science paper that surveyed threats to the boreal, I was told by a public affairs officer that the interview would be on “deep background only” with no attribution to her or her employer. The federal government of Canada, facing some the world’s most serious climate change threats, has gone to great lengths to squelch any discussion of this issue.
Yet even as they redouble their research efforts, scientists know the ultimate answer is not about adaptation or more research, but a rapid reduction in global CO2 emissions, which so far has shown little hope of being achieved. NASA’s Griffith says the situation reminds him of his father, a small-town doctor. “Even when the patient ignored his advice over and over again, he would continue to treat the patient,” he said. “A lot of us in the climate and ecosystem world are finding ourselves dealing with a similar kind of problem.”
POSTED ON 12 OCT 2015
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Marine food chains at risk of collapse, extensive study of world's oceans finds
Source: http://www.theguardian.com/environment/2015/oct/13/marine-food-chains-at-risk-of-collapse-extensive-study-of-worlds-oceans-reveals
The food chains of the world’s oceans are at risk of collapse due to the release of greenhouse gases, overfishing and localised pollution, a stark new analysis shows.
A study of 632 published experiments of the world’s oceans, from tropical to arctic waters, spanning coral reefs and the open seas, found that climate change is whittling away the diversity and abundance of marine species.
The paper, published in the Proceedings of the National Academy of Sciences, found there was “limited scope” for animals to deal with warming waters and acidification, with very few species escaping the negative impact of increasing carbon dioxide dissolution in the oceans.
The world’s oceans absorb about a third of all the carbon dioxide emitted by the burning of fossil fuels. The ocean has warmed by about 1C since pre-industrial times, and the water increased to be 30% more acidic.
The acidification of the ocean, where the pH of water drops as it absorbs carbon dioxide, will make it hard for creatures such as coral, oysters and mussels to form the shells and structures that sustain them. Meanwhile, warming waters are changing the behaviour and habitat range of fish.
The overarching analysis of these changes, led by the University of Adelaide, found that the amount of plankton will increase with warming water but this abundance of food will not translate to improved results higher up the food chain.
“There is more food for small herbivores, such as fish, sea snails and shrimps, but because the warming has driven up metabolism rates the growth rate of these animals is decreasing,” said associate professor Ivan Nagelkerken of Adelaide University. “As there is less prey available, that means fewer opportunities for carnivores. There’s a cascading effect up the food chain.
“Overall, we found there’s a decrease in species diversity and abundance irrespective of what ecosystem we are looking at. These are broad scale impacts, made worse when you combine the effect of warming with acidification.
“We are seeing an increase in hypoxia, which decreases the oxygen content in water, and also added stressors such as overfishing and direct pollution. These added pressures are taking away the opportunity for species to adapt to climate change.”
The research adds to recent warnings over the state of the oceans, with the world experiencing the third global bleaching of coral reefs.
Since 2014, a massive underwater heatwave, driven by climate change, has caused corals to lose their brilliance and die in every ocean. By the end of this year 38% of the world’s reefs will have been affected. About 5% will have died.
Coral reefs make up just 0.1% of the ocean’s floor but nurture 25% of the world’s marine species. There are concerns that ecosystems such as Australia’s Great Barrier Reef, which has lost half its coral cover over the past 30 years, could be massively diminished by 2050 unless greenhouse gas emissions are slashed and localised pollution is curbed.
Meanwhile, warming of the oceans is causing water to thermally expand, fuelling sea level rises caused by melting land ice. Research released in the US on Monday found that Antarctic ice is melting so fast that the whole continent could be at risk by 2100, with severe consequences for coastal communities.
Problems in the ocean’s food chains will be a direct concern for hundreds of millions of people who rely upon seafood for sustenance, medicines and income. The loss of coral reefs could also worsen coastal erosion due to their role in protecting shorelines from storms and cyclones.
“These effects are happening now and will only be exacerbated in the next 50 to 100 years,” Nagelkerken said. “We are already seeing strange things such as the invasion of tropical species into temperate waters off south-eastern Australia. But if we reduce additional stressors such as overfishing and pollution, we can give species a better chance to adapt to climate change.”
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US forests struggle as drought and climate change bite
The speed at which the climate is changing is outstripping forests’ ability to adapt to drier, hotter conditions across vast swathes of the US and Canada
Yosemite national park in California is one of many in the region afflicted by drought – water levels in the Merced River are up to 4 feet lower than usual (Pic: Pixabay)
By Tim Radford
Drought and climate change are now threatening almost all the forests of the continental US, according to new research.
Scientists from 14 laboratories and institutions warn in the journal Global Change Biology that climate is changing faster than tree populations can adapt
Existing forests, effectively and literally rooted to the spot, are experiencing conditions hotter and less reliably rainy than those in which they had evolved.
“Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” says James Clark, professor of global environmental change at Duke University, North Carolina.
He and colleagues synthesised hundreds of studies to arrive at a snapshot of changing conditions and a prediction of troubles ahead.
Ominous predictions
Other research has already delivered ominous predictions for the forests of the US southwest, but the scientists warn that other, normally leafier parts of the continent face increasing stress. Dieback, bark beetle infestation and wildfire risk may no longer be confined to the western uplands.
“While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought,” the authors say.
Professor Clark puts it more bluntly: “Our analysis shows virtually all US forests are now experiencing change and are vulnerable to future declines.
Given the uncertainty in our understanding of how forest species and stands adapt to rapid change, it’s going to be difficult to anticipate the type of forests that will be here in 20 to 40 years.”
Quite what happens depends on the speed at which nations switch from fossil fuels – which release the greenhouse gases that drive global warming – to renewable energy. But because carbon dioxide levels in the atmosphere have risen sharply in the last century, some degree of change is inevitable.
“This is like climate change on steroids, and it happens over much more rapid timescales”
A team of researchers from the University of Colorado Boulder took a closer look at how hotter and drier conditions affect forests. They report in Ecology Letters that felling and forest clearance seem to make things worse, as the newly-exposed edges of an existing forest become more susceptible to drastic temperature changes.
“When you chop down trees, you create hotspots in the landscape that are just scorched by the sun. These hotspots can change the way that heat moves through a landscape,” says the report’s lead author, Kika Tuff, a PhD student at the university’s department of ecology and evolutionary biology.
Low air pressure in the cleared spots pulls the cool moist air from the shade of the trees, to be replaced by hot, dry air. The cleared areas then get the rainfall, while the nearby forest dries.
The warming effect is most pronounced within between 20 and 100 metres of the forest’s edge, where temperatures can be as much as 8°C higher than deep in the forest interior.
Since 20% of the world’s remaining forests lie within 100 metres of an edge, and more than 70% lie within a kilometre of an edge, the discovery suggests that thewarming effect could be happening anywhere, or everywhere.
Tuff says: “This is like climate change on steroids, and it happens over much more rapid timescales.”
Millennium of growth
Meanwhile, to look more closely at the stresses that forests are now facing, two researchers at Washington State University in Vancouver report in the Royal Society Open Science journal that they have made a mathematical model of a forest, enabling them to replicate a millennium of growth and change in about three weeks.
They say they have already used the model to predict increasing fire rates in the hardwood forests of Quebec, because of rising carbon dioxide levels and warmer temperatures.
The model is based on data collected by drone surveys, and it is, they say, the only simulation that creates intricate root systems and canopy structures for each tree. The idea is to provide a tool that can help foresters plan for change.
“One of the major concerns is how climatic changes, in particular droughts, can affect forest structure and dynamics,” they write.
“Drive an hour east along the Columbia River from Vancouver and you will notice a complete transition from very dense forests to savanna and then to desert,” says Nikolay Strigul, assistant professor of mathematics and statistics at Washington State.
“The fear is that drier conditions in the future will prevent forests in places like Washington from re-establishing themselves after a clear-cut or wildfire. This could lead to increasing amounts of once-forested areas converted to desert.”
This article was produced by the Climate News Network
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Principle 8h
Climate change is altering the timing of natural events
Timing matters: Flowers bloom, insects emerge, birds migrate, and planting and hunting seasons are carefully coordinated times in order to take advantage of what other organisms, or the weather, is up to.
But increasing research is showing some of these relationships are falling out of sync as climate change alters important cues, such as the arrival of spring warmth.
"There are going to be winners and losers," said David Inouye, a biology professor at the University of Maryland, Read more…
Climate change is altering the timing of natural events
Timing matters: Flowers bloom, insects emerge, birds migrate, and planting and hunting seasons are carefully coordinated times in order to take advantage of what other organisms, or the weather, is up to.
But increasing research is showing some of these relationships are falling out of sync as climate change alters important cues, such as the arrival of spring warmth.
"There are going to be winners and losers," said David Inouye, a biology professor at the University of Maryland, who has followed seasonal events at the Rocky Mountain Biological Laboratory in Colorado since 1973. "The ultimate outcome will be that some species go extinct and some manage to adapt."
This isn't just a problem for the natural world. Shifts in seasonal events can have direct implications for humans, "because we, as human societies, are adapted to certain seasonal conditions," said Shannon McNeeley, a postdoctoral researcher at the National Center for Atmospheric Research (NCAR) who has studied how a mismatch is playing out in Alaska. There, changes in the moose migrations have made it difficult for native people to obtain the meat they need during the legal hunting season.
Source: http://www.livescience.com/19679-climate-change-seasons-shift-mismatch.html
Featured Interview
For a good summary of impacts on seasonal patterns of plants and animals, visit the National Climate Assessment:
For a brief account of how climate change is affecting hummingbirds and their nectar sources, read this article from Audubon:
Are Early Blooms Putting Hummingbirds At Risk?
Audubon’s chief scientist talks migration, climate change, and what you can do to help.
Jesse Greenspan
Published Apr 07, 2015
No one understands the relationship between climate change and hummingbirds better than Audubon’s chief scientist Gary Langham. He led a groundbreaking study in 2014 that determined that about half of all North American bird species will lose their homes if we don’t do something to stop global warming. Now, to further that study, Audubon is sourcing data from people across the country who host hummingbirds in their backyards. The project, called Hummingbirds at Home, starts up again on April 8.
Langham emphasized the importance of Hummingbirds at Home to Audubon while answering questions about what will happen to the 18 or so hummingbird species in the United States (including rare visitors from Mexico) and the role citizen scientists play in ensuring their survival.
What were some of the regular challenges of a hummingbird migration even before climate change became a factor?
Well, any kind of migration, let alone a hummingbird, is sort of a minor miracle. Imagine a Ruby-throated Hummingbird crossing the Gulf of Mexico in one flight. How in the world does it have enough energy stored up in that little body? It’s just amazing. And then you factor in all of the threats it has to encounter, from weather to manmade structures.
So how has climate change made it worse?
If the nectar sources you depend on bloom too early, you run the risk of showing up after the party’s already over. That’s one of the things that got us thinking about Hummingbirds at Home. The Broad-tailed Hummingbird’s primary food source right now is this big yellow flower called the glacier lily. There’s research out of the University of Maryland showing that the bird is still arriving at its breeding grounds in the Rockies at the same time as previous years, but that climate change is causing the glacier lily to open up earlier and earlier in the season. It’s not hard to extrapolate that soon, Broad-tailed Hummingbirds may show up and not have their main food source. Maybe new flowers will take the glacier lily’s place. Or maybe this shift will turn out to be really bad for the bird.
Are some hummingbirds more endangered by climate change than others?
The hummingbird I grew up with in California, the Anna’s Hummingbird, was mercifully on the climate stable list (in the Audubon Birds and Climate Change Report). But unfortunately, one of the other coastal California hummingbirds, the Allen’s, is listed as climate-endangered. Its summer range seems to be decreasing, whereas the winter range is shifting northward pretty dramatically. The Rufous is also listed as climate-endangered. In some ways, it might be affected even more dramatically than the Allen’s. The other two species listed as climate-threatened are the Calliope and Black-chinned Hummingbirds.
So the Broad-tailed isn’t one of them?
While the Broad-tailed Hummingbird, in the way we did the climate report, was shown to be stable, its food sources are not. The food sources and a lot of ancillary things that are really important to animals are actually not included in our report. And that makes the prospects even more dire than what we projected.
How will Hummingbirds at Home help these species?
If we can better understand what the hummingbirds are feeding on, we can maybe get ahead of the curb and plant things that are either climate-stable or that will properly match up with the birds’ migrations. To me, the next iteration is to generate a specific list of plants that people can use for hummingbirds in their areas.
In the three years since Hummingbirds at Home started, what has stood out to you about the project?
People are very passionate about their backyards and gardens, and they’re very passionate about hummingbirds. Hummingbirds are like raptors. They somehow have this supernatural ability to capture people’s attention. Because hummingbirds come in people’s yards, they’re also a great way to engage kids. One of the things that’s kind of lost in our digital world is that connection to nature.
Is the eventual goal to have something as long-running and as scientifically useful as, say, the Breeding Bird Survey or the Christmas Bird Count?
I think that would be great! I hesitate to forecast anything for an individual project, but I could imagine that it would do just that. Or maybe we’ll broaden it to be more inclusive of a broader range of birds, or maybe it will be absorbed by something else. We want whatever it is we’re doing to feel meaningful to people and be fun and free and family-friendly.
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Climate Impacts on Wildlife
Jessica Aldred
Monday 31 March 2014 07.31 EDT
Source: http://www.theguardian.com/environment/2014/mar/31/ipcc-climate-report-wildlife-impact
Polar bears are seen south of Churchill, Manitoba, in this undated handout photo. Lightning-sparked wildfires along Canada's Hudson Bay are threatening polar bears' summer habitat, encroaching on the old tree roots and frozen soil where females make their dens, an conservation expert on the big white bears said on Thursday. Photograph: Reuters
One focus of the latest report from the UN panel on climate change is the impact on Earth's ecosystems. The report from the Intergovernmental Panel on Climate Change (IPCC) says that in recent decades, many plant and animal species have moved their range, changed numbers or shifted their seasonal activities as a result of warmer temperatures.
Moving on up
Species are matching temperature rises by increasingly shifting their range (the geographic area to which their activity is confined) towards the cooler poles or higher altitudes – sometimes three times faster than previously thought. Species that already inhabit the upper limit of their habitat – such as the polar bear, snow leopard or dotterel – literally have nowhere left to go.
The British comma butterfly has moved 137 miles northward in the past two decades, while geometrid moths on Mount Kinabalu in Borneo have shifted uphill by 59 metres in 42 years. The quiver tree of southern Africa is increasing as it moves towards the south pole, but dying of heat and water stress in its shrinking northern range. Dartford warblers have been steadily moving northwards in the UK while declining on the southern edge of their range in Spain.
A comma butterfly in Kent, UK. Photograph: Robert Pickett/Alamy
In the seas, rising numbers of warm-water crustaceans have been found around Norway's polar islands, while the snow crab has extended its range northwards by up to 311 miles. The IPCC report warns that many species will be unable to move fast enough to track suitable climates, with plants, amphibians and small mammals in flat landscapes or that remain close to their breeding site particularly vulnerable.
Seasonal shift
For many species, climate influences important stages in their annual life cycle, like migration or mating. The report shows major shifts in this "phenology" in recent decades, mainly in the northern hemisphere. "Spring advancement" – the earlier occurrence of breeding, bud burst, breaking hibernation, flowering and migration – has been found in hundreds of plant and animal species in many regions. Migratory birds including the whitethroat, reed warbler and song thrush are arriving earlier, three species of Japanese amphibians have been found to be breeding earlier, while the edible dormouse has been emerging earlier from hibernation by an average of eight days per decade.
Climate change is disrupting flower pollination, research shows
Damian Carrington
Thursday 6 November 2014 12.00 EST
Source: http://www.theguardian.com/environment/2014/nov/06/climate-change-is-disrupting-flower-pollination-research-shows
New research reveals that rising temperatures are causing bees to fly before flowers have bloomed, making pollination less likely
The early spider orchid and miner bee, that depend on each other for reproduction, have become increasingly out of sync as spring temperatures rise, research has shown. Photograph: Friedhelm Adam/Getty Images
Sexual deceit, pressed flowers and Victorian bee collectors are combined in new scientific research which demonstrates for the first time that climate change threatens flower pollination, which underpins much of the world’s food production.
The work used museum records stretching back to 1848 to show that the early spider orchid and the miner bee on which it depends for reproduction have become increasingly out of sync as spring temperatures rise due to global warming.
The orchid resembles a female miner bee and exudes the same sex pheromone to seduce the male bee into “pseudocopulation” with the flower, an act which also achieves pollination. The orchids have evolved to flower at the same time as the bee emerges.
But while rising temperatures cause both the orchid and the bee to flower or fly earlier in the spring, the bees are affected much more, which leads to a mismatch.
“We have shown that plants and their pollinators show different responses to climate change and that warming will widen the timeline between bees and flowers emerging,” said Dr Karen Robbirt, at the Royal Botanic Gardens, Kew and the University of East Anglia (UEA). “If replicated in less specific systems, this could have severe implications for crop productivity.”
She said the research, published in Current Biology on Thursday, is “the first clear example, supported by long-term data, of the potential for climate change to disrupt critical [pollination] relationships between species.”
Three-quarters of all food crops rely on pollination, and bees and other pollinators have already suffered heavily in recent decades from disease, pesticide use and the widespread loss of the flowery habitats on which they feed. In the UK alone, the free fertilisation provided by pollinators is estimated to be worth £430m a year to farmers.
Professor Anthony Davy, also at UEA and part of the research team, said: “There will be progressive disruption of pollination systems with climatic warming, which could lead to the breakdown of co-evolved interactions between species.”
Scientists have already identified a few timing mismatches caused by global warming between species and their prey. Oak tree buds are eaten by winter moths, whose caterpillars are in turn fed by great tits to their chicks, but the synchronicity of all these events has been disrupted.
Suspected mismatches have occurred between sea birds and fish, such as puffins and herring and guillemots and sand eels. The red admiral butterfly and the stinging nettle, one of its host plants, are also getting out of sync.
The new study focused on the early spider orchid Ophrys sphegodes, found in southern England, and the solitary miner bee species Andrena nigroaenea because they have a very close relationship. Other plants can be pollinated by many insects and other insects can pollinate many plants, making it very hard to determine the effect of changing temperatures.
The solitary miner bee is affected more by rising temperatures than the early spider orchid that it pollinates. Photograph: Oxford University
Another challenge is that the temperature effects can be subtle, meaning data has to be collected over a long period. Robbirt and her colleagues realised that the natural history museums in London and Oxford and Kew Gardens had dated specimens of both the orchid and the bee stretching back to 1848.
Analysing all the data, and checking it against recent surveys, revealed that the orchid flowers six days earlier for every 1C increase in spring temperatures. But the effect on the male miner bee was greater, as it emerged nine days earlier.
The female miner bees, which usually emerge later than the male, emerged 15 days earlier. The latter effect meant the male bees were less likely to visit the orchid flowers for pseudocopulation. “The orchids are likely to be outcompeted by the real thing,” said Robbirt.
The UK government published its national pollinator strategy on Tuesday. It was welcomed by the pesticide trade body, the Crop Protection Association and the National Farmers Union. But Joan Walley MP, chair of parliament’s Environmental Audit Committee, said: “I am disappointed the government seems stubbornly determined to keep open the possibility of challenging the EU ban on neonicotinoid pesticides, which have been linked to pollinator declines.”
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Climate Change Throws Nature's Timing Out of Whack
by Wynne Parry 
Timing matters: Flowers bloom, insects emerge, birds migrate, and planting and hunting seasons are carefully coordinated times in order to take advantage of what other organisms, or the weather, is up to.
But increasing research is showing some of these relationships are falling out of sync as climate change alters important cues, such as the arrival of spring warmth.
"There are going to be winners and losers," said David Inouye, a biology professor at the University of Maryland, who has followed seasonal events at the Rocky Mountain Biological Laboratory in Colorado since 1973. "The ultimate outcome will be that some species go extinct and some manage to adapt."
This isn't just a problem for the natural world. Shifts in seasonal events can have direct implications for humans, "because we, as human societies, are adapted to certain seasonal conditions," said Shannon McNeeley, a postdoctoral researcher at the National Center for Atmospheric Research (NCAR) who has studied how a mismatch is playing out in Alaska. There, changes in the moose migrations have made it difficult for native people to obtain the meat they need during the legal hunting season.
"This more subtle seasonal change has not been a main focus of climate research," McNeeley said. "I think it is going to be one that emerges more and more as we see these changes happening, and we start to have more conflicts around this."
Changes in nature
Evidence going back decades and sometimes even longer shows the timing of some biological events is shifting around the world. Studies document the progressively earlier arrival of spring, by about 2.3 to 5.2 days per decade in the last 30 years, according to the Intergovernmental Panel on Climate Change's 2007 report. That report lists studies showing changes in seasonal timing, or phenology, of the first and last leaves on gingko trees in Japan, butterfly emergence in the United Kingdom, bird migrations in Australia, the first leaves and flowers of lilacs in North America, among many others.
But not everything is changing together, leading to complex results.
During his years in the Colorado mountains, Inouye has seen the winter snow melt earlier, the result of warmer springs, less snowfall during the winter and more dust carried in by storms, which accelerates melting. The last frost, however, continues to happen at about the same time.
His work indicates this is bad for the Mormon fritillary butterfly since an early start to the growing season may put caterpillars and the flower buds that could later feed adult butterflies at the mercy of frosts. Migratory hummingbirds, which also consume the flowers' nectar, are arriving earlier in the spring now, but they aren't quite keeping pace with the first flowers, a potential mismatch that could ultimately lead to fewer flowers for the birds to pollinate, said Inouye.
Decades of data show that robins are showing up earlier, as are the hibernating marmots, and there is evidence that this shift is benefiting the marmots, who appear to be putting on more weight during the summer.
Records of spring flowers in Concord, Mass., initially kept by Henry David Thoreau, show that not only are flowers blooming earlier, the species that haven't moved up their first bloom dates are disappearing.
Human implications
Even in modern society, human activities track the seasons. In search of shifts in human phenology, one study looked at national park attendance, and found a shift toward peak attendance earlier in the year for parks located in places where spring is getting warmer.
The effects of climate change are showing up dramatically in the Arctic, and changes in the timing of seasonal events are no exception, McNeeley said. "You are starting to see these seasonality mismatches in a much more enhanced way than you are in the lower 48 [U.S. states]," she said.
These changes are pushing nature and human regulatory systems apart, creating problems for Alaskan natives who depend on wild food, particularly moose, but can only legally hunt it during a specific period. The hunting season, historically, has been timed to the moose migration out of their summer feeding grounds into the territory where they perform their annual mating ritual. But lately the moose have been staying at their feeding grounds until later into the season.
"People haven't had time to harvest moose for winter and then the hunting season shuts down," McNeeley said. "That gives them two choices, either they go without moose … or they have to hunt illegally, which comes with huge penalties if they get caught."
Over the past decade, tribes have sought to shift the hunting season, but their efforts have been almost completely unsuccessful, due largely to biologists' concerns about the effects on the breeding season, she said.
In the lower 48 states, earlier snowmelt and a longer growing season are likely to create conflicts related to water rights, but updating policies will likely be difficult. The fundamental problem is the scarcity of the resource, Douglas Kenney, director of the Western Water Policy Program at the University of Colorado, told AtmosNews, an online publication of NCAR.
"This particular issue of the timing of seasons and phenology and the legal system is something that has been really understudied and I think needs to receive a lot more attention," McNeeley told LiveScience.
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Principle 8i
Human Health and Mortality will be Affected
Human health and mortality rates will be affected to different degrees in specific regions of the world as a result of climate change. Although cold-related deaths are predicted to decrease, other risks are predicted to rise. The incidence and geographical range of climate-sensitive infectious diseases—such as malaria, dengue fever, and tick-borne diseases—will increase. Drought-reduced crop yields, degraded air and water quality, and increased hazards in coastal and low-lying areas will contribute to unhealthy conditions, particularly for the most vulnerable populations.
The wide range of climate-related challenges facing every community are enormous and may appear at times to be overwhelming. The U.S. and other militaries around the world recognize climate change as a serious, potentially catastrophic national and global security threat. Read More…
Human Health and Mortality will be Affected
Human health and mortality rates will be affected to different degrees in specific regions of the world as a result of climate change. Although cold-related deaths are predicted to decrease, other risks are predicted to rise. The incidence and geographical range of climate-sensitive infectious diseases—such as malaria, dengue fever, and tick-borne diseases—will increase. Drought-reduced crop yields, degraded air and water quality, and increased hazards in coastal and low-lying areas will contribute to unhealthy conditions, particularly for the most vulnerable populations.
The wide range of climate-related challenges facing every community are enormous and may appear at times to be overwhelming. The U.S. and other militaries around the world recognize climate change as a serious, potentially catastrophic national and global security threat.
Being aware of the complex, diverse issues is the first step toward building robust, resilient communities and protecting ecosystems. Recently, the Preventive Medicine community, which has years of communicating “bad news” about health and environmental risks to relevant organizations and agencies, began to tackle the health impacts of climate change with a special issue of the American Journal of Preventive Medicine. One article is titled “Community-Based Adaptation to the Health Impacts of Climate Change” by Kristie Ebi and Jan Semenza. Their abstract reads:
“The effects of and responses to the health impacts of climate change will affect individuals, communities, and societies. Effectively preparing for and responding to current and projected climate change requires ongoing assessment and action, not a one-time assessment of risks and interventions. To promote resilience to climate change and other community stressors, a stepwise course of action is proposed for community-based adaptation that engages stakeholders in a proactive problem solving process to enhance social capital across local and national levels. In addition to grassroots actions undertaken at the community level, reducing vulnerability to current and projected climate change will require top-down interventions implemented by public health organizations and agencies.”
For good summaries of climate change impacts on human health, visit the National Climate Assessment:
Climate change affects human communities. So does the mining of fossil fuels, which cause climate change. For information on those impacts, visit these sites:
Eight Ways That Climate Change Hurts Humans
From floods and droughts to increases in violent conflict, climate change is taking a toll on the planet's population
By Sarah Zielinski
SMITHSONIAN.COM
APRIL 10, 2014
Source: http://www.smithsonianmag.com/science-nature/eight-ways-climate-change-hurts-humans-180950475/?no-ist
As climate change makes wet places wetter and dry areas drier, the frequency of drought is expected in increase in certain locations. Droughts, such as this one in Kenya in 2006, can increase food insecurity, especially among the poor. (Brendan Cox/Oxfam/)
It can be easy to think of climate change as a far-off, indirect threat that some future human population will have to overcome. And that even then, the effects of climate change won’t be too bad, or that they won’t hurt people. But as the latest Intergovernmental Panel on Climate Change report, Climate Change 2014: Impacts, Adaptation and Vulnerability, emphasizes, the effects of climate change already can be seen, and members of the current human population already are its victims.
Climate change will hurt and even kill humans in a stunning variety of ways. Here are nine (sometimes unexpected) ways climate change will negatively affect people:
Heat waves: Extreme heat can be deadly, particularly among the poor who may not have the luxury of retreating to air-conditioned rooms. In Australia, for example, the number of dangerously hot days is expected to rise from its current average of four to six days per year to 33 to 45 by 2070. That will translate to more deaths: About 500 people died because of heat in Australian cities in 2011; the Australian government has projected 2,000 deaths per year by the middle of this century.
Floods: Climate change tends to make wet areas wetter and dry areas drier, and so there will be an increase in both flooding and droughts. Flooding is one of the most common natural disasters. Floods displace people from their homes, damage and destroy infrastructure and buildings, and take a toll on an economic level. In 2011 alone, 112 million people worldwide were affected by floods, and 3140 people were killed.
Drought: Unlike a flood, drought is rarely a direct killer. But extremely dry conditions that last for months or years can lead to food and water shortages and rising food prices, which can contribute to conflict. Droughts also have huge economic costs, even in developed countries. New Zealand, for instance, lost more than $3 billion from 2007-2009 because of reduced farm output from drought.
Fire: Increased heat increases fire risk, and climate change is expected to bring more wildfires. The current California drought, for instance, has raised the risk of “explosive” wildfires. And it’s not just burns and injuries from the fire that are the problems. “Smoke from forest fires has been linked…with increased mortality and morbidity,” the IPCC authors write in Chapter 11, “Human Health: Impacts, Adaptation, and Co-Benefits” [pdf].
Crop declines and food shortages: Extreme weather events, such as floods and droughts, will lead to declines in some crops in some areas. While this might be an inconvenience for people in developed countries when it comes to foods like limes and avocados, the situation will be far more dire when it comes to crops like corn and wheat and in countries that already struggle to feed their populations. Food shortages and increases in food prices, which increase the number of malnourished people, are a particular concern in those places that already suffering from food insecurity, such as large portions of Africa.
Infectious diseases: “Climate may act directly by influencing growth, survival, persistence, transmission or virulence of pathogens,” the IPCC scientists write in Chapter 11. Mosquitoes are sensitive to climate—as temperatures rise, they'll find favorable habitats in places that were once too cool for them to live, such as higher latitudes and altitudes. The diseases they transmit, such as malaria, dengue fever, and chikungunya fever, will spread with them.
Studies show that even a small amount of warming can increase malaria transmission under the right conditions. Dengue fever is another worry; it’s increased 30-fold in the last 50 years. And thanks to infected travelers' ability to move across the globe, chikungunya fever has already spread from Africa and Asia to the Caribbean, and may be poised to cross into the mainland Americas—a warming climate will exacerbate this new-found lack of isolation.
Food- and water-borne diseases, too, are a concern. For example, heavy rainfall, which will continue to increase as climate changes, can promote the transmission of water-borne diseases, such cholera and others caused by Vibrio bacteria, particularly in places where there aren’t good methods for disposing of human waste.
Mental illness: Climate change can increase stress, and that is a problem when it comes to mental health. “Harsher weather conditions such as floods, droughts, and heat waves tend to increase the stress on all those who are already mentally ill, and may create sufficient stress for some who are not yet ill to become so,” the IPCC researchers write in Chapter 11.
"When you have an environmental insult, the burden of mental health disease is far greater than the physical," Steven Shapiro, a Baltimore psychologist who directs the program on climate change, sustainability and psychology for the nonprofit Psychologists for Social Responsibility (PsySR), told LiveScience earlier this year. "Survivors can have all sorts of issues: post traumatic stress disorder, depression, anxiety, relationship issues, and academic issues among kids." Slow-developing events like droughts have even been linked to increases in suicide.
Violence and conflict: Human violence rarely has a single cause, but many of the effects of climate change have the potential to contribute to conflict—water and food shortages, soil degradation that makes land less suitable for agriculture, the movement of people as they migrate from lands made less habitable. “Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence by amplifying well-documented drivers of these conflicts such as poverty and economic shocks,” researchers write in the report’s Summary for Policymakers [pdf].
These aren't doomsday scenarios; this isn't fearmongering—we're already seeing an uptick in every item on this list. So anyone hoping to avoid the effects of climate change may be out of luck.
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Leading Health Experts Call For Fossil Fuel Divestment to Avert Climate Change
Source: http://time.com/3935564/health-experts-fossil-fuel-divestment/
Getty Images
'Divestment rests on the premise that it is wrong to profit from an industry whose core business threatens human and planetary health'
More than 50 of the world’s leading doctors and health researchers called on charities to divest from fossil fuel companies in an open letter Thursday. The letter, published in the Guardian, argues that climate change poses a dire risk to public health and that fossil fuel companies are unlikely to take action to reduce carbon emissions without prodding.
“Divestment rests on the premise that it is wrong to profit from an industry whose core business threatens human and planetary health,” the health experts wrote. The case for divestment brings “to mind one of the foundations of medical ethics—first, do no harm.”
The letter is the latest show of support for efforts to halt climate change from the medical community. Recent research has outlined a variety of public health issues caused by climate change, from heath stroke deaths to increased asthma rates. Just this week a study in The Lancet outlined how climate change could erode 50 years of health advances.
Read More: How College Kids Helped Divest $50 Billion From Fossil Fuels
The open letter alluded to those impacts and suggested that divestment would be the best way for global charities to address them. Engaging with fossil fuel companies’ boards has not been shown to work, the researcher wrote, likening the oil industry to the tobacco industry.
“Our primary concern is that a decision not to divest will continue to bolster the social licence of an industry that has indicated no intention of taking meaningful action,” researchers wrote.
The long list of signatories include the editors of The Lancet and BMJ, leading medical journals, as well as medical professors from across the United Kingdom.The letter specifically calls on the Wellcome Trust and the Gates Foundation, two nonprofits that are leading contributors to global health causes, to divestment their multi-billion endowments from fossil fuel companies. Together the companies control total endowments worth more than $70 billion.
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Principle 8j
What Difference Does Half a Degree in Warming Make?
What's the difference between a two-degree world and a 1.5-degree world? The Paris climate conference in 2015 pledged not just to keep warming “well below 2 °C,” but also to "pursue efforts" to limit warming to 1.5 °C.
But how much of a difference can half a degree Celsius make? First, let's do the conversion to °F since that's the units used in the U.S.: 2 °C = 3.6°F and 1.5 °C = 2.7 °F.
So in degrees Fahrenheit, we're talking about a difference of less than 1°F (.9 °F to be exact). That doesn't sound like much of a difference. But adding half a degree of heat to the world's climate system turns out to make an enormous difference. Here's what the science says:
What Difference Does Half a Degree in Warming Make?
Hot Weather
A study last year by Erich Fischer of the Institute for Atmospheric and Climate Science in Zurich found that the risk of what was “once in a thousand days” hot weather has already increased fivefold. His modelling suggests that it will double again at 1.5 degrees and double once more as we go from 1.5 to 2 degrees. The probability of even more extreme events increases even faster.
At two degrees, parts of southwest Asia, including well-populated regions of the Persian Gulf and Yemen, may become literally uninhabitable without permanent air conditioning.
Droughts
The same will be true for droughts, says Carl-Friedrich Schleussner of the Potsdam Institute for Climate Impact Research in Germany. Last year, he reported that the extra half-degree would produce dramatic increases in the likely length of dry spells over wide areas of the globe, including the Mediterranean, Central America, the Amazon basin, and southern Africa, with resulting declines in river flows from a third to a half. Schleussner concluded that going from 1.5 to 2 degrees “marks the difference between events at the upper limit of present-day natural variability and a new climate regime, particularly in tropical regions.”
Famines
Some researchers predict a massive decline in the viability of food crops critical for human survival. The extra half-degree could cut corn yields in parts of Africa by half, says Bruce Campbell of the International Center for Tropical Agriculture. Schleussner found that even in the prairies of the U.S., the risk of poor corn yields would double.
Ecosystems
Ecosystems would feel the difference too. Take tropical coral reefs, which already regularly come under stress because of high ocean temperatures, suffering “bleaching” especially during El Nino events – as happened on the Great Barrier Reef in Australia this year. Most can now recover when the waters cool again, but today’s exceptional temperature may soon become the new normal. “Virtually all tropical coral reefs are projected to be at risk of severe degradation due to temperature-induced bleaching from 2050 onwards,” as warming slips past 1.5 degrees, reports Schleussner.
By some estimates, curbing warming at 1.5 degrees could be sufficient to prevent the formation of an ice-free Arctic in summer, to save the Amazon rainforest, and to prevent the Siberian tundra from melting and releasing planet-warming methane from its frozen depths. It could also save many coastal regions and islands from permanent inundation by rising sea levels, particularly in the longer run.
In 2100, the difference in sea level rise between 1.5 and 2 degrees would be relatively small: 40 centimeters versus 50 centimeters. But centuries later, as the impact of warmer air temperatures on the long-term stability of the great ice sheets of Greenland and Antarctica takes hold, it would be far greater. Michiel Schaeffer of Climate Analytics, a Berlin-based think tank, calculates that by 2300, two degrees would deliver sea level rise of 2.7 meters, while 1.5 degrees would limit the rise to 1.5 meters.
Source: http://e360.yale.edu/feature/what_would_a_global_warming_increase_15_degree_be_like/3007/
Principle 8k
A Summary of Impacts
Principle 8l
Local Relevance
Climate Change and Montana: Impacts on the Region and on Montana
Montana’s climate is already changing. Average spring temperatures in the state have risen by almost 4°F over the last 55 years, with winter temps close behind with a 3°F increase. Summer temps have also climbed just over 1°F.
Precipitation patterns have changed as well, but not evenly across the state. In general, the Northern Rockies are now seeing less winter snow while the southeastern plains are receiving slightly more spring and fall rain. But, that additional rain is coming in fewer, more severe, storms. Read more…
Source: http://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/
montana/howwework/climate-change-in-mt-web.pdf
Climate Change and Montana: Impacts on the Region and on Montana
Montana’s climate is already changing. Average spring temperatures in the state have risen by almost 4°F over the last 55 years, with winter temps close behind with a 3°F increase. Summer temps have also climbed just over 1°F.
Precipitation patterns have changed as well, but not evenly across the state. In general, the Northern Rockies are now seeing less winter snow while the southeastern plains are receiving slightly more spring and fall rain. But, that additional rain is coming in fewer, more severe, storms.
In Montana global warming puts agriculture, water availability, tourism, forest health, and millions of species at risk:
- Since 1999, Montana’s wheat yields have been 15-30% less than the previous 10 years. The models developed by MSU on global warming impacts on Montana agriculture predict a further 20-40% decrease in yields.
- Of the 150 glaciers present in Glacier National Park 100 years ago, only 26 remain. Even these are expected to vanish within 30 years.
- In Montana, Spring melt-off occurs 15 days earlier than 50 years ago according to University of Montana scientist, Steve Running, with the Montana Climate Center.
- Snowfall in the Missoula area has fallen from 55 inches to 40 inches, and the number of frost-free days has increased by 15 in the last 50 years.
- Flathead Lake reported the highest ever mid-lake temperature on July 22, 2003: 76 degrees at the deepest point.
Source: http://meic.org/issues/montana-global-warming-pollution-and-climate-change/facts-figures-and-policies-on-global-warming/
from the National Climate Assessment
Forest Fires
Western U.S. wildfires have increased dramatically since 1970. Years with warmer spring and summer temperatures tend to have the most fires. In the coming decades,more warming and shrinking snowpack in the West is expected to cause even more big fires. Click on your state to see the trend.
click a topic to learn more about climate change impacts in the Plateau area
- Local Climate Change
Over the last century, the average temperature in Helena, Montana, has increased 1.3°F, and precipitation has decreased by up to 20% in many parts of the state. Over the next century, climate in Montana may change even more. For example, based on projections made by the Intergovernmental Panel on Climate Change and results from the United Kingdom Hadley Centre’s climate model (HadCM2), a model that accounts for both greenhouse gases and aerosols, by 2100 temperatures in Montana could increase by about 4°F in spring and summer (with a range of 1-8°F) and 5°F in fall and winter (with a range of 2-10°F). Precipitation is estimated to increase by roughly 10% in all seasons except winter, when the range of estimated increase is 15-40%. The amount of precipitation on extreme wet or snowy days in winter is likely to increase. The frequency of extreme hot days in summer would increase because of the general warming trend. Although it is not clear how severe storms would change, an increase in the frequency and intensity of winter storms is possible.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf - Human Health
Higher temperatures and increased frequency of heat waves may increase the number of heat-related deaths and the incidence of heat-related illnesses. Montana, with its irregular, intense heat waves, could be susceptible. The elderly, particularly those living alone, are at greatest risk.
Warming and other climate changes may expand the habitat and infectivity of disease-carrying insects, thus increasing the potential for transmission of diseases. A recent study has concluded that a 5-9°F temperature increase would cause a significant northern shift in Western equine encephalitis outbreaks. Mosquitos capable of transmitting this disease already are present in Montana. If Montana’s climate becomes warmer and wetter, mosquito populations could increase and conditions may become more favorable for disease transmission.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf - Water Resources
Water resources are affected by changes in precipitation as well as by temperature, humidity, wind, and sunshine. Changes in streamflow tend to magnify changes in precipitation. Water resources in drier climates tend to be more sensitive to climate changes. Because evaporation is likely to increase with warmer climate, it could result in lower river flow and lower lake levels, particularly in the summer. If streamflow and lake levels drop, groundwater also could be reduced. In addition, more intense precipitation could increase flooding.
Western Montana drains into the Columbia River system, and most of the remaining areas of the state drain to the east into the Missouri River or its major tributary, the Yellowstone River. Winter snow accumulation and spring melt are key processes that affect the runoff of all rivers within the state. A warmer climate would lead to earlier spring snowmelt, resulting in higher streamflows in winter and spring and lower streamflows in summer and fall. Earlier spring snowmelt could reduce the performance of the reservoir system in western Montana, thus reducing summer and fall runoff, which is critical for power generation, fisheries protection, recreation, and other uses. Increased rainfall could mitigate some of these effects, but it also could lead to increased flooding.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf - Agriculture
The mix of crop and livestock production in a state is influenced by climatic conditions and water availability. As climate warms, production patterns could shift northward. Increases in climate variability could make adaptation by farmers more difficult. Warmer climates and less soil moisture due to increased evaporation may increase the need for irrigation. However, these same conditions could decrease water supplies, which also may be needed by natural ecosystems, urban populations, industry, and other sectors.
Understandably, most studies have not fully accounted for changes in climate variability, water availability, and imperfect responses by farmers to changing climate. Including these factors could change modeling results substantially. Analyses that assume changes in average climate and effective adaptation by farmers suggest that aggregate U.S. food production would not be harmed, although there may be significant regional changes.
In Montana, agriculture is a $1.8 billion annual industry, one-half of which comes from livestock, mainly cattle. Just over 20% of the crop acreage is irrigated. The major crops in the state are wheat, barley, and hay. In a warmer climate wheat yields could increase by more than a third, and changes in barley and hay yields could vary between -8% and +13%, depending on whether irrigation is used, leading to changes in acres farmed and production. For example, barley yields could rise while production falls because of a decrease in barley acres farmed. An increased dependence on irrigation is possible, depending on the relative balance between rainfall and increased evaporation.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf - Forests
Trees and forests are adapted to specific climate conditions, and as climate warms, forests will change. These changes could include changes in species, geographic range, and health and productivity. If conditions also become drier, the current range and density of forests could be reduced and replaced by grasslands and pasture. Even a warmer and wetter climate could lead to changes; trees that are better adapted to these conditions, such as fir and spruce, would thrive. Under these conditions, forests could become more dense. These changes could occur during the lifetimes of today’s children, particularly if change is accelerated by other stresses such as fire, pests, and diseases. Some of these stresses would themselves be worsened by a warmer and drier climate.
With changes in climate, the extent of forested areas in Montana may change little or could decline by as much as 15-30%. The uncertainties depend on many factors, including whether soils become drier and, if so, how much drier. Hotter, drier weather could increase the frequency and intensity of wildfires, threat- ening both property and forests. Drier conditions could reduce the range and health of lodgepole and Douglas fir forests, and increase their susceptibility to fire. With increases in rainfall, however, these effects could be less severe. Grass and range- land could expand into previously forested areas along the eastern slope of the Rocky Mountains and into some of the western valleys. Milder winters could increase the likelihood of insect outbreaks and of subsequent wildfires in the dead fuel left after such an outbreak. These changes would significantly affect the character of Montana forests and the activities that depend on them.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf - Ecosystems
Ecosystems in Montana are diverse, ranging from grasslands and deserts to mountain shrublands, forests, meadows, and alpine tundra. They also include numerous wetlands and streams. Because of elevation changes and human land use, many habitats are fragmented and restricted in area. Changes in temperature and precipitation caused by climate change could affect the location and productivity of these ecosystems.
Warming and changes in precipitation could affect alpine areas, causing tree lines to rise by roughly 350 feet for every degree Fahrenheit of warming. Mountain ecosystems such as those found in Glacier National Park could shift upslope, reducing habitat for many subalpine species. Alpine animals and species, many of which are unique to the region, could disappear from the highest elevations. Mountain glaciers such as those found in Glacier National Park are expected to shrink, possibly leading to higher stream temperatures and decreased runoff. This would adversely affect aquatic biota, including trout species. Changes in rainfall and snowfall also could alter streamflows and wetlands, affecting wildlife and possibly accelerating the invasion of non-native plants into streamside habitats. Aquatic species that are sensitive to water temperature could be affected adversely by climate change. Brown trout and rainbow trout could lose habitat.
Source: http://www.spatialsci.com/files/images/EPA_MT_climchange.pdf
Principle 8m
Misconceptions about this Principle
The Misconception
Global warming will be good for humans
The misconception or myth goes something like this: “…Two thousand years of published human histories say that warm periods were good for people. It was the harsh, unstable Dark Ages and Little Ice Age that brought bigger storms, untimely frost, widespread famine and plagues of disease.”
The Science
Scientist predict climate change will bring many more costs than benefits.
The science says: climate change will have many more costs than benefits. While it is expected that global warming may bring a few benefits in the short term, it is expected that over the longer term, it will bring few or no benefits to human society and instead will do great harm at considerable cost. Learn more…
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm
The Science
Scientist predict climate change will bring many more costs than benefits.
The science says: climate change will have many more costs than benefits. While it is expected that global warming may bring a few benefits in the short term, it is expected that over the longer term, it will bring few or no benefits to human society and instead will do great harm at considerable cost.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm
- AgricultureWhile CO2 is essential for plant growth, all agriculture depends also on steady water supplies, and climate change is likely to disrupt those supplies through floods and droughts. It has been suggested that higher latitudes – Siberia, for example – may become productive due to global warming, but the soil in Arctic and bordering territories is very poor, and the amount of sunlight reaching the ground in summer will not change because it is governed by the tilt of the earth. Agriculture can also be disrupted by wildfires and changes in seasonal periodicity, which is already taking place, and changes to grasslands and water supplies will impact grazing and welfare of domestic livestock. Increased warming may also have a greater effect on countries whose climate is already near or at a temperature limit over which yields reduce or crops fail – in the tropics or sub-Sahara, for example.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - HealthWarmer winters would mean fewer deaths, particularly among vulnerable groups like the aged. However, the same groups are also vulnerable to additional heat, and deaths attributable to heat waves are expected to be approximately five times as great as winter deaths prevented. It is widely believed that warmer climes will encourage migration of disease-bearing insects like mosquitoes. Malaria (transmitted by mosquitoes) is already appearing in places it hasn’t been seen before.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - Polar MeltingWhile the opening of a year-round ice-free Arctic passage between the Atlantic and Pacific oceans would confer some commercial benefits, these are considerably outweighed by the negatives. Detrimental effects include loss of polar bear habitat and increased mobile ice hazards to shipping. The loss of ice albedo (the reflection of heat), causing the ocean to absorb more heat, is also a feedback loop that furthers warming—with enormous and potentially catastrophic consequences; the warming waters increase glacier and Greenland ice cap melt and raise the temperature of Arctic tundra. Warmer tundra then releases methane, a very potent greenhouse gas (methane is also released from the sea-bed, where it is trapped in ice-crystals called clathrates). Melting of the Antarctic ice shelves is predicted to add further to sea-level rise with no benefits accruing.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - Ocean AcidificationA cause for considerable concern, there appear to be no benefits to the change in pH of the oceans. This process is caused by additional CO2 being absorbed in the water, and may have severe destabilizing effects on the entire oceanic food-chain.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - Melting GlaciersThe effects of glaciers melting are largely detrimental, the principle impact being that one-sixth of the world’s population depends on fresh water supplied each year by natural spring melt and regrowth cycles. Melting glaciers mean those water supplies, used as drinking water and for agriculture, may fail.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - Sea-level RiseMany parts of the world are low-lying and will be severely affected by modest sea rises. Rice paddies are being inundated with salt water, which destroys the crops. Seawater is contaminating rivers as it mixes with fresh water further upstream, and aquifers used for drinking water and agriculture are becoming polluted. Given that the IPCC did not include melt-water from the Greenland and Antarctic ice-caps due to uncertainties at that time, estimates of sea-level rise are feared to considerably underestimate the scale of the problem. There are no proposed benefits to sea-level rise.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - EnvironmentalPositive effects of climate change may include greener rain forests and enhanced plant growth in the Amazon, increased vegetation in northern latitudes and possible increases in plankton biomass in some parts of the ocean. Negative responses may include further growth of oxygen-poor ocean zones, contamination or exhaustion of fresh water, increased incidence of natural fires, extensive vegetation die-off due to droughts, increased risk of coral extinction, decline in global phytoplankton, changes in migration patterns of birds and animals, changes in seasonal periodicity, disruption to food chains and species loss.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - EconomicThe economic impacts of climate change may be catastrophic, while there have been very few benefits projected at all. The Stern report made clear the overall pattern of economic distress, and while the specific numbers may be contested, the costs of climate change were far in excess of the costs of preventing it. Certain scenarios projected in the IPCC AR4 report would witness massive migration as low-lying countries were flooded. Disruptions to global trade, transport, energy supplies and labour markets, banking and finance, investment and insurance, would all wreak havoc on the stability of both developed and developing nations. Markets would endure increased volatility and institutional investors such as pension funds and insurance companies would experience considerable difficulty.
Developing countries, some of which are already embroiled in military conflict, may be drawn into larger and more protracted disputes over water, energy supplies or food, all of which may disrupt economic growth at a time when developing countries are beset by more egregious manifestations of climate change. It is widely accepted that the detrimental effects of climate change will be visited largely on the countries least equipped to adapt, socially or economically.
Source: https://www.skepticalscience.com/global-warming-positives-negatives.htm - Show More
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