What Is Biochar?

Written By Teacher: Elaine Makarevich

Elaine is a New Jersey educator with 30 years of teaching experience in grades K-6. The earth and the natural world have always been a focus of her life and throughout her career as her students learned critical lessons about their planet when visiting her indoor or outdoor classrooms.

Biochar is a special kind of charcoal made by heating plant materials without oxygen. It helps trap carbon in the soil, keeping it out of the atmosphere, and also improves soil health by holding water and nutrients. While biochar has great potential for climate solutions, scaling up production and use remains a challenge. Teaching students about biochar can spark discussions on sustainable agriculture, carbon sequestration, and innovative climate solutions.

For hands-on learning, explore Biochar Production to understand how biochar is made and used. The NJ Ag Lessons on Climate Change connect agriculture to climate science with engaging activities. How Dirt Works takes a deeper dive into soil health, showing how dirt plays a critical role in ecosystems and carbon storage.

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.

Biochar is a type of processed plant matter that is very rich in carbon. Lightweight, black and very porous, it looks and feels very much like charcoal. But where charcoal is used for cooking and heat, biochar is used in soils to help grow crops.

It can also help address climate change. Biochar is one of several “carbon removal” techniques that target carbon dioxide (CO2), the most important climate-warming greenhouse gas humans have been adding to the atmosphere.

Biochar and the carbon cycle

As plants grow, they breathe in CO2 from the air, using the carbon they absorb to build their tissues. Then they die and rot or decompose, releasing CO2 into the air again.

But if they are turned into biochar, the carbon is instead converted into a solid, which can stay locked in soil for many years. In this way, plants become a sort of carbon removal engine, drawing climate-warming CO2 out of the air and storing it in the ground.