A teaspoon of soil can contain more microbes than there are people on the planet.

Those microbes affect the climate by helping determine how much carbon is trapped in the soil and how much is released to the atmosphere. It’s a delicate balance, and one that scientists say is shifting as temperatures rise.

Thomas Crowther is professor of ecosystem ecology at ETH Zurich, a university in Switzerland.

“As we warm those soils, those microbes become more active, and that means they release more carbon into the atmosphere,” he says.

He says that makes the climate warmer, which in turn makes the microbes even more active, “which pumps more carbon out of the soil, which warms the planet further, leading to a feedback that can actually really accelerate the rate of climate change.”

Crowther says to make matters worse, some microbes survive better than others when the soil is warmer, and those tend to be the microbes that release carbon to the atmosphere quickly.

So to keep soil from getting too warm, Crowther suggests restoring grasslands and forests that provide shade.

“It’s managing those zillions of microbial cells effectively that is going to be one of the most powerful tools that we have in the fight against climate change,” he says.

Reporting credit: Stephanie Manuzak/ChavoBart Digital Media.