Study: Permafrost thaw appears to be accelerating water discharge from Arctic lakes
The changes taking place in the Arctic are extensive and profound, and new discoveries continue to shape our understanding of what is still to come. A study published last month found that the region is warming almost four times faster than the global average, much faster than researchers thought. Another study this week also found that even if we stopped burning fossil fuels today, the melting of the Greenland ice sheet has already raised Earth’s sea levels by nearly a foot.
These conclusions stem from a new analysis of modern satellite data, which continues to provide researchers with a powerful new tool for studying climate change. The new study, led by University of Florida postdoctoral researcher Elizabeth Webb, follows a similar line of thinking, with the authors using satellite data to remotely monitor changes in surface water across the Arctic and using machine learning to assess patterns of change that occurred between 2000 and 2021.
“One of the things I really like about using remote sensing is that you can answer big questions that don’t seem possible — we have the ability to answer them now, it’s only in the last 5, 10 years that we’ve had the computing power and resources to Get the job done,” Webb said.
The team’s analysis revealed large-scale drying in lake-rich regions of the Arctic — across Canada, Russia, Greenland, Scandinavia and northern Alaska. These bodies of water make up 20 to 40 percent of the Arctic lowlands and are an important source of water for remote communities and habitat for wildlife. While climate scientists had expected them to dry up at some point in the future, the claim that the process was already underway contradicted the model’s story.
Initially, climate change is expected to expand these lakes as snow and ice on the ground melt, with a drying effect not expected until mid-century or sometime in the next. Instead, the team suspects that thawing permafrost, the permafrost slabs that lie in much of the Arctic, is pushing eroded soil toward lakes and creating new channels for drainage. Other factors include rising temperatures and increased fall rainfall.
Study co-author Jeremy Lichstein said: “Increased rainfall would reduce surface water, which seems anomalous. But it turns out that there is a physical explanation already in the scientific literature: Rain brings heat into the soil and accelerates permafrost destruction. Thaw, which can open up underground passages to drain the surface.”
The notion that the permafrost is thawing faster than expected is undoubtedly worrying, as this frozen soil harbors large amounts of organic matter and greenhouse gases, which are released into the atmosphere as they thaw. Scientists have called for a rethink on the burning of fossil fuels to stop these changes seen in the Arctic and the wider effects of global warming.
“The snowball is already rolling, and continuing to do what we’re doing is not going to work,” Webb said.