Two distinct climate regimes that could trigger runaway methane emissions are emerging in Siberia due to Arctic warming, new research suggests.
While western Siberia is becoming wetter in response to rising heat and moisture transported from the North Atlantic Ocean, eastern Siberia is getting drier and more prone to wildfires, a study published Aug. 6 in the journal
Conversely, eastern Siberia is influenced by a climate pattern known as the Arctic Oscillation, which causes atmospheric air pressure to “seesaw” between the Arctic and the Northern Hemisphere’s middle latitudes. Climate change affects the Arctic Oscillation, leading to persistent high-pressure systems that intensify heat waves, reduce cloud cover and promote wildfires in eastern Siberia, Palmer said.
The climate models showed that methane emissions will increase with temperature rise and that the increase could become steeper the hotter the world gets, triggering a feedback loop.
“Eastern Siberia appears to be the main driver of the projected increase because it is warming faster than western Siberia and has seen a sharp rise in extreme wildfires,” Palmer said. “Whether that trend continues will depend on how much vegetation remains available to burn, but there is also evidence that fires may be accelerating permafrost thaw and the release of methane from previously frozen ground.”
However, the rise in methane emissions reported in the study is small relative to global and projected future emissions, especially if wildfires are already destabilizing eastern Siberia’s permafrost, Palmer said.
“Siberia’s vast permafrost carbon store is a sleeping giant,” he said. “Continued warming risks waking up a much larger source of greenhouse gases.”
