Permafrost experiment shows surprising amount of CO₂ release

Permafrost experiment shows surprising amount of CO₂ release

Enlarge / The study took place near Denali National Park, pictured here. (credit: faungg’s photos / flickr)

Emissions from burning fossil fuels, cutting down forests, and agricultural practices aren’t the only things that control how high atmospheric CO2 will go in the future. There are also feedbacks in the Earth’s climate system, where warming temperatures cause the release of carbon into the atmosphere. One of these is the release of carbon from permafrost as it thaws and decays.

Unlike emissions, which we can control through actions like retiring a coal-burning power plant, humans can only indirectly change the behavior of these feedbacks—the sooner we halt warming, the smaller their emissions will be. Figuring out exactly how much (and how fast) those feedbacks will emit is a major challenge for climate science.

A striking new study led by César Plaza works on the first step of this challenge: measuring

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The oceans absorbed extra CO₂ in the 2000s

The oceans absorbed extra CO₂ in the 2000s

Enlarge / Plankton swirls in the Gulf of Aden between Yemen and Somalia. (credit: NASA Earth Observatory)

Tracking climate change means (among other things) tracking annual changes in global greenhouse gas emissions and the corresponding increases in the atmospheric CO2 concentration. This can get confusing, though, because there isn’t a perfect year-to-year correlation between the two.

Our CO2 emissions are released into the atmosphere, but the atmosphere interacts with other parts of Earth’s carbon cycle, which pull some CO2 out. In the short term, the two sinks that matter most are the oceans and the ecosystems on land. CO2 dissolves into seawater to maintain an equilibrium with the air, and photosynthetic organisms on land and in the oceans take in CO2. Shifting ocean currents or weather on land that affects plant growth will alter the amount of CO2 being taken out of

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