As the Arctic tundra warms, soil microbes likely will ramp up CO2 production
Climate change is warming the Arctic tundra about four times faster than the rest of the planet. Now, a study suggests that rising temperatures will spur underground microbes there to produce more carbon dioxide — potentially creating a feedback loop that worsens climate change.The tundra is “a sleepy biome,” says Sybryn Maes, an environmental scientist at Umeå University in Sweden. This ecosystem is populated by small shrubs, grasses and lichen growing in cold soils rich with stored organic carbon. Scientists have long suspected that warming will wake this sleeping giant, prompting soil microbes to release more of the greenhouse gas CO2 (SN: 8/11/22). But it’s been difficult to demonstrate in field studies.
Maes’ team included about 70 scientists performing measurements in 28 tundra regions across the planet’s Arctic and alpine zones. During the summer growing season, the researchers placed clear, open-topped plastic chambers, each about a meter in diameter, over patches of tundra. These chambers let in light and precipitation but blocked the wind, warming the air inside by an average of 1.4 degrees Celsius. The researchers monitored how much CO2 microbes in the soil released into the air, a process called respiration, and compared that data with measurements from nearby exposed patches. More