Sue Natali has dedicated her life to watching the Arctic melt before her eyes. As an ecologist and biochemist at Woods Hole Research Center she travels to some of the most remote locations on Earth to dig holes in the ground and measure the carbon that seeps out. What she learns helps us better understand why permafrost is essential to the health of the planet. She chatted with us about what it's like working in the frozen North, why an increase in fires is damaging the frozen landscape, and how to preserve moose meat (and soil samples) in an ice cave in Siberia.
Why do we care about permafrost?
My research focuses on permafrost--how much carbon is in the permafrost, and what happens to it when it thaws. That's important because there's a lot of carbon stored in permafrost in the form of organic matter, leaves, microbes, dead and decaying material. When a leaf falls in a warm environment it decomposes right away and returns to air as carbon dioxide and methane. But because the Arctic is really cold, when the plant material falls most of it doesn't decompose. A lot sits there and builds up and builds up. Some gets frozen into permafrost.
It's really cool depending on how the permafrost forms you can find whole plant material. There's a tunnel near Fox, Alaska, just outside Fairbanks that was dug in the 1960s. When you walk through the tunnel -- it's in the side of cliff -- as you walk in you're getting deeper toward the back going back 40,000 years, walking backwards in time. You can see giant ice wedges, you can see animal bones, and plant material that's not decomposed because it's frozen.
So the reason I focus on permafrost thaw is because of the global implications. It stores a lot of carbon. There's twice as much carbon stored in permafrost as in the atmosphere, and three times more than in the all the world's forest biomass. This carbon is protected now because it's frozen. But when it thaws it becomes available to microbes, which eat the organic matter, use it for energy, and release carbon dioxide and methane.
If soils are well-aerated, the organic matter is decomposed to carbon dioxide. When the ground is wet, methane and carbon dioxide are released. Methane is important because it's 30 times more powerful as a greenhouse gas than carbon dioxide on a 100-year time scale.