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A team of over 70 scientists, including the late Jianwu (Jim) Tang, senior scientist in the �ֲ���ý Ecosystems Center, used open-top chambers (OTCs) to experimentally simulate the effects of warming on 28 tundra sites around the world. The massive synthesis study was published in Nature in April. Anne Giblin, director of the Ecosystems Center, is quoted in this article by Sierra Club Magazine.

New analysis shows that over time, this process could turn tundra ecosystems from carbon sinks to sources of emissions.

Beneath snow and the low-lying vegetation that can survive in a tundra’s frigid temperatures is soil that holds onto a massive store of carbon, keeping it out of the atmosphere. Unlike some of the world’s best known carbon sinks, which are dense forests—such as the Amazon—a tundra is a vast open landscape with views unencumbered by trees. Rising global temperatures threaten to upend this order, however, turning tundras from key areas of carbon sequestration into sources of carbon emissions. New research, published earlier this month in , shows the likely role that plants and microbes will have in exacerbating these changing dynamics and helping scientists create more accurate climate models to predict the trajectory of global warming. 

“Warming can strongly stimulate plants and microbes in the tundra system to become more active and respire more carbon,” said Sybryn Maes, a postdoctoral researcher at KU Leuven in Belgium and lead author on the paper. “We really need to have as much understanding as possible … in the current climate change context.”

To help understand how much carbon tundra soil could release if global warming continues unabated, the authors compiled data from 56 artificial warming experiments in Arctic and alpine tundra ecosystems. These data come from experiments that ran from less than one year up to 25 years. Each experiment used a piece of equipment called an open-top chamber, which has a top open to the elements and clear sides, creating a mini greenhouse. The simple setup works well for Arctic ecosystems, where there often isn’t an electricity hookup nearby that could power a soil heater or tall vegetation that would ruin the chamber’s warming effect. .