What are Greenhouse Gases?

Written By Teacher: Liz Ransom

As a High School Spanish teacher and student newspaper advisor, Liz has taught for over 20 years and has served as World Languages Department Chair and K-6 summer camp activities leader. She has worked in Ohio, Maine, New Jersey, Maryland, and Chile.

Empowering students with the facts about greenhouse gases not only helps counteract misinformation but also bolsters nearly any lesson on the climate crisis. For example, teachers can encourage middle school students to expand their understanding of greenhouse gases and human impact on the climate through this social studies lesson Climate Change Claims.  High school students can watch this video Greenhouse Effect and Greenhouse Gases to help answer their questions about the links between topics as diverse as industry, lifestyle, diet, transportation, deforestation and climate change.

Written By: MIT Environmental Solutions Initiative

The MIT Climate Change Engagement Program, a part of MIT Climate HQ, provides the public with nonpartisan, easy-to-understand, and scientifically-grounded information on climate change and its solutions.

Greenhouse gases are gases—like carbon dioxide (CO2), methane, and nitrous oxide—that keep the Earth warmer than it would be without them. The reason they warm the Earth has to do with the way energy enters and leaves our atmosphere. When energy from the sun first reaches us, it does so mainly as light. But when that same energy leaves the Earth, it does so as infrared radiation, which we experience as heat. Greenhouse gases reflect infrared radiation, so some of the heat leaving the Earth bounces off the greenhouse gases in our atmosphere and comes back to the Earth’s surface. This is called the “greenhouse effect,” in a comparison to the heat-trapping glass on a greenhouse.

The greenhouse effect is not a bad thing. Without it, our planet would be too cold for life as we know it. But if the amount of greenhouse gases in the atmosphere changes, the strength of the greenhouse effect changes too. This is the cause of human-made climate change: by adding greenhouse gases to the atmosphere, we are trapping more heat, and the entire planet gets warmer.