Climate change is causing a sea change in the Arctic. As the Arctic warms at nearly four times the rate of the rest of the world, a new study has revealed a threat that surprises scientists: Arctic lakes, the “building blocks of the Arctic ecosystem”, are completely disappear.
The study, published in Nature Climate Change, found that in just 20 years, lakes in the Panarctic region – the northern parts of Canada, Russia, Greenland, Scandinavia and Alaska – have shrunk or have completely dried up. Lakes represent between 20% and 40% of the Arctic lowlands.
According to the University of Florida, whose postdoctoral researcher Elizabeth Webb led the study, the disappearance of the lakes “raises a new wake-up call” about the state of the global climate.
“The endangered lakes act as the cornerstones of the Arctic ecosystem,” the school said in a press release. “They provide an essential source of fresh water for local indigenous communities and industries. Threatened and endangered species, including migratory birds and aquatic creatures, also depend on lake habitats for their survival.
For Webb, the results were a surprise. Scientists had long expected Arctic lakes to expand with climate change as ground ice continued to melt, and climate models have shown that drying up would not be seen until at least 2060 or 2150. But based on Webb’s research, it appears that melting permafrost creates drainage. channels that add soil erosion, rather than water, to arctic lakes.
“Our results suggest that permafrost thaw is happening even faster than we as a community expected,” Webb said. “It also indicates that the region is likely on the path to landscape-scale drainage in the future.”
The reason for the degradation of the lake is twofold, according to the study: rising temperatures and increased fall rainfall.
October 2020 to September 2021 was the seventh warmest year on record for Arctic lands, according to a National Oceanic and Atmospheric Administration report, with temperatures rising nearly 3 degrees Celsius (37.4 degrees Fahrenheit ) since the mid-1960s.
Earlier this month, a separate team of scientists found the Arctic was warming almost four times faster than the rest of the world, and some areas of the Arctic Ocean were warming up to seven times faster . Shrinking sea ice and heat cycles between the ocean and the atmosphere are only adding to the rise in global temperatures.
Regarding increased rainfall, Jeremy Lichstein, Webb’s adviser and co-author of the study, said it might seem counterintuitive to have a helping hand in endangered lakes, but that it is in fact a documented event.
“Rainwater carries heat through the ground and accelerates permafrost thaw, which can open underground channels that drain the surface,” he said.
And thawing permafrost isn’t just detrimental to Arctic lakes — it also risks emitting even more carbon as the atmosphere continues to be supersaturated with greenhouse gases. Such a case could contribute to an even more crushing cycle of global melting in the region: rising temperatures will cause more ice and permafrost to melt, which will then only allow the heat to build up.
“Permafrost soils store nearly twice as much carbon as the atmosphere,” Webb said. “A lot of ongoing research suggests that as permafrost thaws, this carbon is likely to be released into the atmosphere as methane and carbon dioxide.”
While the study is new, it echoes what the National Park Service has witnessed in Alaska, where many bodies of water have dried up and become covered in new vegetation. Citing previous research, the park said that from 2000 to 2017, there was an average water loss in the state’s Arctic parks of about 1,730 acres per decade. The agency said 1,878 surface acres of the lake disappeared in 2018 alone.
There’s a saving grace to this, according to Webb’s research. If the lakes dry up, this can prevent the permafrost from drying out as quickly as it would if the lakes expanded.
But the best way to prevent continued melting of ice in the Arctic region, Webb said, is for the world to reduce its impact on global warming while we can. The impacts of warming the world is already experiencing – intense droughts, more devastating storms and extreme heat – cannot be stopped.
For the Arctic, this means that air temperatures and autumn rains will only continue to increase, according to the study. This is a negative impact on local ecosystems, but also for humans, as the water in Arctic lakes is often the “only viable source of fresh water” for surrounding communities.
A drastic reduction in fossil fuels would significantly reduce greenhouse gases in the atmosphere to help minimize the impact that climate change will have on humanity in the future.
“The snowball is already rolling,” Webb said. “It won’t work to keep doing what we’re doing.”
First published on Aug 31, 2022 / 8:56 AM
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