Is Methane Worse Than Carbon Dioxide?

Written By Teacher: Emily Rogers

Emily has a bachelor’s degree in English and French and a master’s degree in library and information science. She spent seven years teaching information evaluation and research skills as a school librarian in K-8 public schools. As a lifelong resident of Southern Louisiana, Emily has a particular interest in how climate change affects coastal regions. She hopes to connect educators with resources that will help them to teach their students about the disproportionately adverse effects of climate change on historically marginalized communities.

Greenhouse gases like methane and carbon dioxide are crucial to understanding climate change, but what makes some gases more powerful than others? Introduce older students to molecular structure and energy transfer by exploring how molecules move and absorb infrared light. Students can connect chemistry to real-world climate issues. Teachers could incorporate this topic into a physics class by having students model molecular vibrations and resonance using simulations or physical models to explore how different greenhouse gases absorb infrared radiation. In elementary classrooms, teachers can introduce students to the greenhouse gases and their properties to set the stage for more in-depth learning in higher grade levels. Encouraging them to think about these interactions helps build a deeper understanding of why reducing methane emissions is such a high priority in addressing global warming.

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.

When scientists talk about greenhouse gases “trapping heat” in the atmosphere, they’re actually talking about how these gases interact with infrared light. That’s because energy from the sun enters the Earth as a mix of visible, ultraviolet and infrared light, but it leaves the Earth almost entirely in the infrared.

Some molecules—the greenhouse gases, like carbon dioxide (CO2) and methane (CH4)—can grab infrared light on its way out. “So what happens is that infrared energy gets absorbed by the molecule,” says Desiree Plata, associate professor of civil and environmental engineering and director of the MIT Methane Network. “And that molecule enters an excited state. As it's relaxing back down, it releases some of that energy as heat, and that heat can go to outer space or can come back to planet Earth.”

This is the reason the buildup of greenhouse gases in the atmosphere is warming our planet. But it doesn’t explain why some molecules are more potent greenhouse gases than others. Methane, for instance, traps around 120 times as much heat as CO2 does moment to moment.