New research suggests that Arctic warming is creating two different climate patterns in Siberia that could lead to rapid increases in methane emissions.
Western Siberia is becoming wetter because of rising temperatures and moisture from the North Atlantic, while eastern Siberia is becoming drier and more vulnerable to wildfires. The Yenisei River separates these two climate regions.
Rising Methane Emissions Across Siberia
From 2010 to 2023, Siberia’s methane emissions increased by about 5% annually. Western Siberia released methane from thawing soils, while eastern Siberia released it through wildfires.
growing permafrost thaw, wetland activity, and wildfires. However, the size and continued rise of these emissions was unexpected.
During the study period, annual methane emissions increased by around 13.2 million tons (12 million metric tons), similar to the global rise in methane emissions from wetlands. Although Siberia currently contributes about 5% of global methane emissions, it is becoming one of the fastest-growing natural sources of methane worldwide.
Palmer and his team combined satellite data with measurements taken near the ground to track Siberia’s methane emissions over time. Rather than calculating emissions from individual sources, they used a methane flux inversion model to reduce uncertainty in their estimates to about 10%.
Challenges of Monitoring Methane in Siberia
Because Siberia is enormous, remote, and has limited monitoring equipment, collecting consistent methane data is difficult. The Russia-Ukraine war has also made access more challenging for many scientists. Satellites are therefore especially useful for monitoring the region. Although satellite observations depend on sunlight, most methane emissions occur during spring and summer, when Siberia receives more sunlight.
The study found that Arctic warming increases methane emissions through different processes in western and eastern Siberia because the two regions experience different climate conditions. Climate models also suggest that further warming could release millions of tons of greenhouse gases stored in forests and permafrost, potentially speeding up global warming.
In western Siberia, most methane comes from thawing permafrost, which is ground that remains frozen for at least two years.Siberia holds 46% of Northern Hemisphere permafrost, storing vast amounts of carbon.
Western Siberia is affected by the Scandinavian atmospheric circulation pattern. Global warming causes this pattern to bring more heat and moisture from the North Atlantic into the region. Rising temperatures thaw permafrost, allowing microbes to release methane.
In contrast, eastern Siberia is affected by the Arctic Oscillation, a climate pattern involving changes in air pressure between the Arctic and the middle latitudes. Climate change can alter this pattern, creating long-lasting high-pressure conditions that increase heat waves, reduce cloud cover, and raise the risk of wildfires in the region.
Climate models indicate that methane emissions will rise as temperatures increase. Moreover, emissions could grow even faster as the planet becomes hotter, creating a feedback cycle that contributes to further warming.
Eastern Siberia’s Rising Methane Emissions
Eastern Siberia may drive future methane increases due to faster warming and rising wildfires. However, future emissions will depend partly on how much vegetation remains to burn. Wildfires may also speed up permafrost thaw, releasing methane from previously frozen ground.
Continued warming could greatly increase methane emissions. Siberia’s enormous stores of carbon in permafrost could become a major source of greenhouse gases if rising temperatures continue.
Read the original article on: livescience
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