Last April, Joe Biden presented the US Congress with a grand idea: farmers across the nation could plant cover crops that would remove carbon dioxide from the air—and get paid for doing it. The White House followed up by pinning the country’s ambitious 2030 climate goals on “farmers using cutting-edge tools to make American soil the next frontier of carbon innovation.”
The offset industry, working on the same concept, has proffered some staggering numbers. In 2019, start-up Indigo Ag announced its Terraton Initiative, an effort to unlock the potential of agricultural soil to remove one trillion tons of CO2 from the atmosphere (equivalent to over 25 years of human emissions).
It’s a compelling concept. Farming around the world has depleted the carbon naturally found in soils. By applying modern agricultural science (from crop selection to no-till farming), Indigo believes that farmers could increase yields, store carbon—and enable the sale of lucrative offsets to fund the whole process.
But the deeper researchers dig, the less settled the science seems. Is it irresponsible to re-invent farming just as extreme weather, war, and deglobalization threaten our ability to feed the world? And is the race to turn farms into carbon banks driven by science, or disaster capitalism?
• • •Sowing A Crop of Carbon
1. The carbon vault beneath our feet. The world’s plants and animals contain about 560 billion tons of carbon, and there’s another 800 billion tons in the atmosphere. But soil contains nearly twice as much carbon again—an astonishing 2,500 billion tons. Improving soil’s collection and retention of carbon even by a small percentage could substantially roll back the carbon clock. Adopted globally, simple techniques such as adding compost or biochar, and converting to legumes, could store another 4 gigatons of carbon annually—more than the emissions from every passenger car in the world—according to researchers at the Natural Resource Ecology Lab at Colorado State University.
2. Speeding up nature: A low tech solution. New technologies could potentially store another 2 or 3 gigatons, say the researchers. For example, spreading crushed-up alkaline rock over farmland using existing agricultural equipment could pack millions of years of natural geological