New research shows that western Siberia is becoming wetter as global temperatures rise, while eastern Siberia is getting drier, and both changes are increasing methane emissions. A study published in the journal Science on August 6 highlights these two contrasting climate patterns, divided by the Yenisei River, which are emerging due to Arctic warming. Methane is a potent greenhouse gas, more effective at trapping heat in the atmosphere than carbon dioxide, and its increased release could further accelerate global warming. Between 2010 and 2023, methane emissions from Siberia grew by about 5% each year. In western Siberia, methane is mainly released through microbial activity in thawing permafrost and wet soils. In contrast, eastern Siberia emits methane primarily through biomass burning and wildfires, which are becoming more frequent due to rising temperatures. Over the study period, total methane emissions from Siberia increased by about 13.2 million metric tons, nearly matching the rate of methane increase from wetlands around the world. Siberia currently contributes about 5% of global methane emissions, but it is becoming one of the fastest-growing natural sources of this gas. Researchers used satellite data and a methane flux inversion system to track emissions, keeping uncertainty in their estimates to about 10%. Monitoring the region is difficult because of its vast size, remote location, and limited access for scientists, especially during winter when satellite observations are less reliable. The study found that Arctic warming is causing different methane release patterns in western and eastern Siberia, influenced by separate climate systems. Western Siberia is affected by the Scandinavian atmospheric pattern, which brings more warmth and moisture from the North Atlantic, leading to permafrost thaw and the release of stored carbon. Eastern Siberia is influenced by the Arctic Oscillation, a climate pattern that can lead to high-pressure systems, heat waves, and more frequent wildfires. Climate models predict that further warming could release millions of tons of greenhouse gases stored in Siberia's forests and permafrost, creating a feedback loop that accelerates global warming. Eastern Siberia is expected to be the main driver of future methane increases due to its faster warming and rising number of extreme wildfires. However, the increase in methane emissions from Siberia is still relatively small compared to global emissions, especially if wildfires are already destabilizing the region's permafrost. Scientists describe the vast carbon stores in Siberia's permafrost as a "sleeping giant," warning that continued warming could awaken a much larger source of greenhouse gases.