Arctic Lakes Are Vanishing Amid Rising Temperatures

Climate change is causing a dramatic shift in the Arctic. As the Arctic warms at nearly four times the rate of the rest of the world, a new study has found a threat that's surprising scientists: Arctic lakes, the "cornerstones of the Arctic ecosystem," are completely vanishing. 

The study, published in Nature Climate Change, found that over the course of just 20 years, lakes across the pan-Arctic region – the northern parts of Canada, Russia, Greenland, Scandinavia and Alaska – have either shrunk or dried up completely. Lakes make up between 20% and 40% of the Arctic lowlands.

The lakes' disappearance "flashes a new warning light" on the state of global climate, according to the University of Florida, whose postdoctoral researcher Elizabeth Webb led the study.

"The vanishing lakes act as cornerstones of the Arctic ecosystem," the school said in a news release. "They provide a critical source of fresh water for local Indigenous communities and industries. Threatened and endangered species, including migratory birds and aquatic creatures, also rely on the lake habitats for survival."

For Webb, the findings were a surprise. Scientists long expected that Arctic lakes would expand with climate change as ground ice continued to melt and climate models showed that drying would not be seen until at least 2060 or 2150. But based on Webb's research, it appears as though the thawing permafrost is creating drainage channels that add soil erosion, rather than water, to the Arctic lakes.

"Our findings suggest that permafrost thaw is occurring even faster than we as a community had anticipated," said Webb. "It also indicates that the region is likely on a trajectory toward more landscape-scale drainage in the future."

The reasoning for the lake degradation is two-fold, according to the study: rising temperatures and increased autumn rainfall. 

October 2020 to September 2021 was the seventh-warmest year on record over Arctic lands, according to a report by the National Oceanic and Atmospheric Administration, with temperatures up nearly 3 degrees Celsius (37.4 degrees Fahrenheit) since the mid-1960s. 

Earlier this month, a separate team of scientists found that the Arctic is warming nearly four times faster than the rest of the world, and some areas in the Arctic Ocean warming up to seven times as fast. Shrinking sea ice and the heat cycles between the ocean and atmosphere only elevate the rising global temperatures.

As far as the increased rainfall, Jeremy Lichstein, Webb's adviser and study co-author, said that it might seem counterintuitive for that to have a hand in the vanishing lakes, but that it's actually a documented occurrence. 

"Rainwater carries heat into the soil and accelerates permafrost thaw, which can open up underground channels that drain the surface," he said. 

And melting permafrost isn't just detrimental to Arctic lakes – it also risks emitting even more carbon as the atmosphere continues to be oversaturated with greenhouse gases. Such an instance could contribute to an even more overwhelming cycle of overall melting in the region: rising temperatures will lead to more melting of ice and permafrost which will then only enable heat to amplify. 

"Permafrost soils store nearly two times as much carbon as the atmosphere," said Webb. "There's a lot of ongoing research suggesting that as permafrost thaws, this carbon is vulnerable to being released to the atmosphere in the form of methane and carbon dioxide."

Though the study is new, it echoes what the National Park Service has witnessed in Alaska, where many bodies of water have dried out and become covered in new vegetation. Citing past research, the park said that from 2000 to 2017, there was an average water loss across the state's Arctic parks of about 1,730 acres per decade. The agency said that 1,878 acres of lake surface disappeared in just 2018. 

There is one saving grace to this, Webb's research found. If the lakes are drying up, it may prevent permafrost from drying as fast as it would if the lakes were expanding. 

But the best way to prevent continued ice melting across 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 already sees – intense droughts, more devastating storms and extreme heat – can't be stopped. 

For the Arctic, this means that air temperatures and autumn rain will only continue to increase, the study says. It's a negative impact on local ecosystems, but for humans as well, as Arctic lake water is often the "only viable source of fresh water" for surrounding communities. 

A drastic reduction in fossil fuels would significantly lower 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's not going to work to keep on doing what we're doing."

First published on August 31, 2022 / 8:56 AM

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