Nowhere is safe from the climate crisis, but some regions are suffering more than others. The Pacific edge of the Arctic Ocean is one of those regions, and it’s changing in big, scary ways. The region has gotten warmer and lost ice over the past century, but in a paper published in Nature Climate Change on Monday, researchers say the region underwent a “sudden and dramatic shift” from 2017 to 2019. They fear the effects could be irreversible, in some ways mirroring a shift happening on the Atlantic side as well.
“Many changes persisted in 2018 and even into 2019, suggesting that 2017 was not a passing oddity of brief consequence to social-ecological systems, but a sign of what is to come,” the paper says.
Usually, the Arctic ice melts throughout the year’s warmer months, and refreezes throughout the colder ones. These seasonal cycles in sea ice and water temperatures drive the areas ecosystems. In the winter, for instance, whales, Pacific walruses, seals, and seabirds migrate southwards into the Bering Sea. Coastal indigenous communities depend on many of those species for food. But rising temperatures, melting ice, and other resulting physical and biological changes in the area are wreaking havoc on these systems.
The researchers specifically examined data on water temperatures, sea ice levels, and wildlife patterns from the the Bering and Chukchi marine shelf, which are located between Alaska and Russia. Even for an area that’s seen rapid warming over the past several decades, the levels of changes they saw were abnormally bad. In January 2017—in the dead of winter—sea ice in the region was at below-average levels. In the following months, some areas became entirely sea-ice free. Henry Huntington, the study’s lead researcher and consultant on climate issues in Alaska, found the lack of sea ice in the northern Bering Sea and Chukchi Sea in wintertime mind-boggling.
“I didn’t know that was even possible until it happened,” he told Earther in an email. Previously, some scientists thought that even as the area underwent changes, winters would remain cold and dark, letting the system reset itself every winter. “Now we know that isn’t necessarily true.”
The loss of ice and warmer-than-average water temperatures triggered a number of troubling changes up and down the food web. Huntington said warm water, for instance, forceed plankton and fish deeper into the water in search of cooler temperatures, which put them out of reach for diving birds. That caused birds to starve.
Aquatic mammals were also affected. Seals eat small animals that hang out around the edges of sea ice, so as ice melted more rapidly, scientists observed that spotted seal pups were thinner and smaller than normal. In the spring and summer of 2018, scientists found 280 seal carcasses on the beaches in the northern Bering and southern Chukchi seas, roughly five times the annual average between 2014 and 2017. Changes in the distribution of marine mammals isn’t just a problem for the ecosystems but also for local indigenous communities who hunt them.
“The community of Utqiagvik on the northern coast had a very poor whale hunt in the fall of 2019 because the whales simply were not in the area, unlike all previous years,” said Huntington.
The scientists expect that waters will warm even further, winters will become even shorter, and sea-ice levels will continue to shrink. The resulting changes in the Arctic could make the climate crisis—already gripping the region much more intensely than scientists thought—far worse.
“Sea ice reflects sunlight, whereas open water absorbs sunlight,” said Huntington. “Taking sea ice away results in warmer water, which leads to less sea ice. This is a classic positive feedback loop, meaning that loss of sea ice contributes to further loss of sea ice.”
Scientists have separately documented a number of other impacts reshaping the region, including thawing permafrost, landslides, melting land ice, and coastal erosion. More research on all of these impacts will have to be done to understand the implications of the changes in the Arctic. That will be necessary both to help ecosystems and people living in the region adapt to what’s in the pipeline. How successful those efforts are won’t be just important for life along the Bering and Chukchi marine shelf. As Huntington said, “we are all affected by what happens in the Arctic.”
Source: gizmodo.com
