You probably remember your fifth-grade science: plants absorb carbon dioxide, which, through a process called photosynthesis, is converted into carbohydrates and oxygen.
The carbohydrates help the plant grow. The oxygen is a waste product that allows the rest of us to breathe.
Carbon dioxide, of course, is one of the biggest greenhouse gases that are contributing to climate change - it is the second most abundant of those gases after water vapor. It would be helpful, then, to store some of that carbon in the ground, where it would not be released into the atmosphere for centuries, and then only slowly.
This is where farmers and something called regenerative agriculture can come in.
Scientists have figured out ways for farmers essentially to take carbon dioxide out of the air and sequester it in the earth. The idea has been around for a number of years, but I was recently reintroduced to it by a particularly informative article Maddie Oatman wrote for Mother Jones magazine (Oatman was with me last year at a National Press Foundation fellowship on food and agriculture).
In the article, Oatman writes that some of the carbon absorbed by plants is leaked out into the soil below through its roots. Microbes in the soil then convert this carbon (and the carbon from decomposed plants) into humus, which helps dirt retain moisture and nutrients. Basically, it is what helps plants to grow.
Keeping a root system viable with living plants is beneficial to the soil, and therefore to farmers. But most farmers typically do the opposite. After they have harvested their crops, they plow the remaining plants into the earth.
Doing so allows them to plant their crops more easily the next year. But as soil scientists have discovered, the practice also diminishes the health of the soil. To see the same yields, farmers have to use more artificial fertilizer.
The new movement, regenerative agriculture, encourages farmers not to till their fields but rather to leave the plants and stems on top of the ground. Then the farmers can plant a cold-weather cover crop such as rye, Dutch white clover or hairy vetch around them.
The cover crop roots feed carbon into the soil, while the cover crop and the remains of the previous crop shield the soil from the elements. This allows the microbes to multiply and also keeps the carbon in the soil from turning into carbon dioxide and returning to the atmosphere.
One of the farmers Oatman talked to said that his yield had not improved using this method, though other farmers have noticed that theirs does. But he saves money on fuel (it can be thousands of dollars for an average-sized farm) and labor by not having to run his tractor over the field as many times. He also saves money by not having to buy artificial fertilizer.
And there is another new incentive to engage in regenerative agriculture. Last week, Bayer announced that it was joining other companies in paying farmers to capture carbon in the soil through such methods as cover-crop planting and no-till farming.
Bayer would give the farmers credits to purchase Bayer products, such as seeds. But the company Oatman wrote about, Indigo Agriculture, promises to pay farmers actual cash - $15 for every metric ton of carbon they capture in the soil. That would give the farmer anywhere from $30 to $45 per acre.
That would be a significant addition to a farmer's income. In 2019, according to the article, an acre of corn brought an average of $650 to a farmer.
Indigo can make these payments because it plans to sell carbon credits to companies looking for a way to comply with federal guidelines on pollution without the expense of actually limiting its emissions. Such companies as Microsoft, JetBlue and Shell either already are buying or plan to buy credits as a way to diminish their net carbon footprint, the article states.
Indigo has announced an ambitious plan to use regenerative agriculture worldwide to sink a teraton of carbon - that's more than 2 billion tons - into the ground.
That may be impossible. Some experts doubt the earth can absorb that much carbon, while others say the figure is achievable only if every farmer in the world practices regenerative agriculture - and does a good job of it.
Furthermore, other carbon offset markets have not been popular in the United States, and one, the Chicago Climate Exchange, collapsed in 2010 after supply suddenly outstripped demand.
So the payments for carbon credits may or may not come through in the long term, but farmers who have tried regenerative farming say their initial cost in new equipment is made up for in their savings.
Forward-thinking farmers may at least want to think about it.