Why Does Burning Coal Produce More CO₂?

Written By Teacher: Meighan Hooper

Meighan has been an arts educator and instructional designer since 2007. Originally from Ontario, Canada, she began teaching internationally in the Middle East and Asia in 2013. Meighan has designed programs of study based on a variety of curriculum including Canadian, American standards-based, Primary Years Program (IB), and British National curriculum.

To get students thinking about carbon emissions, consider using a Student News Article such as "China Now Second Largest Carbon Emitter in History, Still Well Behind US" as a bell ringer. Students can adjust the article to their reading level and use the included formative assessment to check their understanding. Current events and new articles make it easy to integrate climate education into your lessons. For a lighter and age-appropriate approach, try the digital read-aloud "Sven's Search for Clean Energy" to introduce elementary students to fossil fuels and clean energy alternatives. These tools make teaching about climate change accessible and engaging for all age groups.

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.

All living things are made mostly of carbon-based molecules—so fossil fuels, which are made of once-living things, are as well. But coal “has a lot more carbon in it” than oil or gas, says Gregory Stephanopoulos, an MIT professor of chemical engineering. The “carbon-intensity” of each fuel determines how much CO2, or carbon dioxide, each produces. 

Coal, oil, and gas were created over millennia as buried organic material decayed.

Today’s coal began as plants growing in and near swamps millions of years ago, which died and became covered with water. Cut off from oxygen, the plants slowly decomposed, and bacteria and chemicals in the water reacted to create a substance called peat.

As geology changed, water and sediment covered the peat, burying it under layers of earth and minerals, and applying pressure.

“When organic matter is buried in sediments, it gets cooked at higher temperatures,” says Shuhei Ono, an MIT professor of geochemistry. This heat aided chemical reactions and broke down molecules, pushing out hydrogen and oxygen and leaving behind higher percentages of carbon. Thus, peat became coal.