If students are to understand climate change, they have to understand the fundamentals of the greenhouse effect. Specifically, they need to know:

• What the greenhouse effect is.
• The role of certain trace gases in trapping heat.
• The role of water vapor and that it is the most abundant but not necessarily the most important greenhouse gas.
• The most important greenhouse gases—CO₂ and methane.
• That natural processes cannot explain recent changes in the Earth's climate.

Perhaps the greatest challenge in teaching this principle is conveying how even relatively small changes in certain trace gases can have monumental impacts on Earth's climate and why. Another challenge is overcoming the claims of climate deniers or skeptics (because they have been repeated so often) that natural processes can account for our warming climate. Indeed, the unscientific claims and untruths of deniers make this principle more challenging to teach, while at the same time presenting an opportunity for you to teach how science works and how students can distinguish pseudo-science and junk science from real science.

This principle presents a great opportunity for students to learn some basic chemistry and physics, why some molecules like CO₂ trap heat and others like O₂ do not. It can also be used as a way for students to gain an understanding of good science because many of the "junk-science" claims of deniers challenge the science around this principle.

Middle school students can think about this issue metaphorically (that greenhouse gases trap heat like a blanket traps heat) while learning the basics of the science and physics.

In high school, can look at the levels of CO₂ over the last 100 years and compare that with changes in global temperatures. They can explore the "What's Warming the World" interactive graphic. They can do research on the potential impact the thawing of the permafrost will have on the levels of methane in the atmosphere and what that means for global temperatures.

In the introductory undergraduate curriculum, students can explore the impact carbon dioxide, methane, nitrous oxide and sulfur hexafluoride, the "Global Warming Potential" or GWP of each, and how long each lasts in the atmosphere (chemistry). They can explore how ultraviolet or shortwave radiation travels easily through the Earth's atmosphere to warm the earth, but how that heat or infrared (longwave) radiation is trapped by the atmosphere (physics).

A Blanket Around the Earth: NASA Global Climate Change

NASA Earth Observatory: Natural vs Enhanced Greenhouse Effect

Carbon Dioxide Controls Earth's Temperature