Tractors emit carbon dioxide. Livestock emit methane. All told, agriculture causes about ten percent of global warming pollution.

Soil samples
Soil samples in Liberia illustrate ‘composting with a twist.’ Photo: Courtesy of Dawit Solomon.

So Dawit Solomon of Cornell University is looking for ways to produce more food without making climate change worse. He thinks a technique used by West African farmers for hundreds of years may be part of the answer.

Consider it composting with a twist. Farmers combine agricultural and kitchen waste, then add ash and char residue from cooking.

Solomon: “When you apply charred material, this is highly resistant to decomposition, and it can stay for hundreds of years.”

The char holds carbon, keeping it in the ground and out of the atmosphere. And when the mix is added to soil, the result is …

Solomon: “… the transformation of infertile and highly degraded tropical soils into an enduringly fertile black and highly carbon-rich soil.”

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In Solomon’s study area, just one percent of the land was treated with the biochar compost. But it produced nearly 25 percent of the total food the farmers grew. So Solomon says the technique could both help farmers grow more food and reduce global warming pollution.

Reporting credit: Rosie Simon/ChavoBart Digital Media.

Bud Ward was editor of Yale Climate Connections from 2007-2022. He started his environmental journalism career in 1974. He later served as assistant director of the U.S. Congress's National Commission...