BEIJING, Aug. 7 (Xinhua) -- As the Arctic warms at an accelerating pace and Siberia's permafrost thaws, growing volumes of methane are seeping into the atmosphere, which could cancel out about 20 percent of the methane reductions that nations are counting on to meet 2050 climate goals, according to new research.
A study by an international team, led by the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences, found that between 2010 and 2023, annual methane emissions across Siberia rose by about 12 million metric tonnes. That single regional rise accounted for 92 percent of the entire increase from the world's wetlands over the same period.
The findings were published in the journal Science.
For years, Siberia's vast, remote landscape has made its methane emissions notoriously hard to measure, with estimates varying so widely that the region became a major hole in the global methane budget.
Using a technique called flux inversion, the team combined satellite data with ground-based observations -- including rare tall-tower monitors inside Siberia -- to shrink the uncertainty in their estimates to roughly 10 percent.
The researchers discovered that the Yenisei River marks a climatic divide. In western Siberia, wetter conditions are driven by winter atmospheric patterns that bring heat and moisture, fueling methane production at a rate of about 0.4 million tonnes per year. In eastern Siberia, warmer, drier weather is fueling more wildfires, which boost fire-related methane emissions at nearly double that rate -- about 0.7 million tonnes annually.
Under a high-emissions scenario, the study projects that by 2050, the increase of Siberian methane emissions could offset about one-fifth of the human-caused cuts needed to meet international climate targets -- with eastern Siberia accounting for most of that increase.
"If we ignore these regional feedbacks, estimates of the global methane budget could be seriously biased," said Liu Yi, a professor at the IAP. "Changes in natural sources could offset part of our mitigation efforts."
The study offers a clear warning: the Arctic is no longer just a passive responder to climate change. It is becoming an active force that could quietly erode some of the world's most carefully laid climate plans, Liu added. ■
