Are There Cost-Effective Carbon Offsets?

Written By Teacher: Teresa Pettitt-Kenney

Hi there! My name is Teresa and I just finished my Bachelor's degree in Environmental Science and am excited to pursue environmental education in the future! I am extremely passionate about climate change, equitable climate action, and how education can work to address these issues. 

Carbon offsets are becoming increasingly common in our world. Your students may run into carbon offsets when shopping for clothes or looking at flights for family trips, but it isn’t always clear what they are or if they are effective. How does planting a tree compare to reducing emissions through solar farms? As you investigate these questions below, you can also think of ways to introduce and learn about carbon offsets in your classroom. Take your students through a comprehensive overview with this Carbon Offsets and Climate Change lesson or start the discussion in an exciting way with the Carbon Runner online game. 

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.

First, a little background. When you buy a carbon offset, you're buying a commitment from a company or organization that it will remove a certain amount of greenhouse gases from the atmosphere. Offsets are designed to compensate for a buyer’s emissions. For example, one common way people purchase offsets is along with a flight. While commercial zero-carbon flights do not exist (yet), some airlines offer offsets as a way for you, as the flyer, to “cancel out” the amount of carbon your flight will produce.

These projects can be very different from one another. Your offset purchase might actually remove CO2 from the atmosphere, such as by supporting a project that is planting or protecting trees, or it might prevent greenhouse gases from entering the atmosphere in the first place, like by building solar or wind farms (which can replace power plants that burn fossil fuels).

With so many different approaches to fighting climate change, it’s not surprising that not all carbon offsets cost the same. Luckily, they are easy to compare as cost measurements are pretty standard: what is the price of keeping one ton of CO2 out of the atmosphere? If you’re funding “direct air capture” machines that pull CO2 out of the air to bury underground, the price per ton of CO2 can be as high as $1,200. Most offset purchases, however, will run you in the neighborhood of $10 to $30 a ton, and some can be even cheaper.