Short grasses and plants growing near the Arctic Circle absorb carbon dioxide from the atmosphere. As they die, the carbon-rich plant matter is pushed into the soil, where it freezes.
In warmer conditions, the plant matter would be broken down quickly by bacteria another microorganisms in the soil, releasing more carbon dioxide into the atmosphere. In the Arctic tundra, the dead plant matter remains frozen about a foot below the surface, which makes the tundra a giant vault of carbon dioxide, says Matthew Wallenstein, a Colorado State University ecologist.
But the vault is opening. As the planet warms, microbes hiding in the Arctic will feed on the thawed plant matter. As they eat, they release carbon dioxide as a byproduct.
NewsHour science correspondent Miles O’Brien caught up with Wallenstein and a team from Colorado State University, who are digging up frozen cores of Alaskan soil to study these microbes.
“This is frozen,” says researcher Megan Machmuller, gesturing to the tundra. “So, that prevents the release of the carbon to the atmosphere, but as temperatures are warming very fast here in the Arctic, this – the microbes – speed up, decompose carbon faster perhaps by releasing more carbon to the atmosphere, and that’s really what we’re trying to understand.”
O’Brien has more in this report for the National Science Foundation series “Science Nation.”*
*For the record, the National Science Foundation is also an underwriter of the NewsHour.