Transcript:

music; ambience: walking on the tundra

Trudging across the spongy mosses of the Alaskan tundra, ecologist Ted Schuur is on his way to his research plot, wondering whether the ground beneath his feet is slowly thawing. Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Permafrost is soil that has been frozen for at least two years. There is evidence that in northern latitudes the permafrost layer is melting and dead plant life in the soil is starting to decompose and release the carbon that’s been stored in it. Ted Schuur and his team are studying the impact of the thawing and this new influx of old carbon. But first, he needs to know how much carbon is being released by the living plants in the area.

“So, every day plants are taking up carbon because they’re photosynthesizing. Most of the carbon that comes back out of plants is the same age. They take it in that day or that month, and they also respire it back out. It’s a very quick cycle. That’s not true for the soil, so carbon that’s gone into the soil has been, first, in the plant, then, the plant dies and it’s in the soil. It’s in the soil for a long time before it comes out.”

Ted hopes to compare the amount of new carbon entering the ecosystem from living plants to the rates of old carbon released by thawing permafrost.

“When we measure the whole ecosystem, we’re able to use these measurements today to say, Well, how much came from plants versus how much came from the soil where it’s been around a lot longer?’”

Ted Schuur believes that there is more carbon locked up in permafrost than there is in our atmosphere. So, the release of only part of the permafrost’s carbon in the form of carbon dioxide could have a significant impact on global climate. Carbon Dioxide, one of the so-called greenhouse gases, traps the earth’s heat in our atmosphere.

Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.