Climate Change Is Ravaging the Arctic, Report Finds

Dec 10, 2019 by

The New York Times

A lake on the edge of the Humboldt Glacier in Greenland in September.
Credit…NASA/EPA, via Shutterstock

Temperatures in the Arctic region remained near record highs this year, according to a report issued on Tuesday, leading to low summer sea ice, cascading impacts on the regional food web and growing concerns over sea level rise.

Average temperatures for the year ending in September were the second highest since 1900, the year records began, scientists said. While that fell short of a new high, it fit a worrying trend: Over all, the past six years have been the warmest ever recorded in the region.

“It’s really showing that we have a system that’s under duress,” said Donald K. Perovich, a professor of engineering at the Thayer School of Engineering at Dartmouth College and the lead author of the report’s chapter on sea ice.

The results are from the annual Arctic report card, a peer-reviewed assessment produced by the National Oceanic and Atmospheric Administration that takes a broad look at the effects of climate change in the region and compares current findings with the historical record. The Arctic is of interest to researchers because it is warming twice as fast as the rest of the planet, causing changes both in the ocean and on land.

“If I had gotten a report card like this as a kid, I would have been grounded,” Dr. Perovich said. “It’s not showing much improvement at all. Things are getting worse.”

In July, Reykjavik, Iceland, experienced its warmest month on record. Similarly, Anchorage, Alaska, set heat records in June, July and August.

But the extreme temperatures were not confined to summer. In Svalbard, Norway, December temperatures were 10 degrees Fahrenheit, or about 5.5 degrees Celsius, warmer than the 1981-2010 temperature average. A study published this year in the journal Science Advances found that, under a high-emissions scenario, late autumn temperatures in some parts of the Arctic could reach more than 23 degrees Fahrenheit warmer than the historical average.

Warming temperatures were just one of the concerning changes documented in the report. Ninety-five percent of the Greenland ice sheet thawed this reporting year, buoyed in part by the onset of an earlier-than-usual melt, prompting growing concerns over sea level rise. A separate study published on Tuesday in the journal Nature found that Greenland was losing ice seven times faster than it did in the 1990s, a pace that would add roughly three additional inches of sea level rise by century’s end.

Arctic sea ice — which helps cool the polar regions, moderates global weather patterns and provides critical habitat for animals like polar bears — continued to decline this year, matching the second lowest summer extent recorded since satellite records began in 1979. (It was tied with 2016 and 2006.)

In particular, the Bering Sea, site of some of the largest commercial fisheries in the United States, saw unprecedented reductions in sea ice for the second winter in a row. What sea ice does exist tends to be younger, thinner and more susceptible to melting.

“The very old ice that’s been around for more than four years used to be 33 percent of the ice cover and now it’s 1 percent,” Dr. Perovich said. “One way to think about that is, when we look at the area that the old ice covered back in 1985 it was a little bit bigger than the United States east of the Mississippi River. And all that’s left now is Maine.”

The loss of sea ice changes how much heat is in the ocean, which in turn affects fisheries and ecosystems, creating cascading effects within this interconnected system. Among those affected are the more than 70 Indigenous communities in Alaska including the Inupiat, Central Yupik, Cupik, St. Lawrence Island Yupik and Unangan peoples. For the first time in the report’s 14-year history, it included input from some of these communities.

They said that the warming Arctic was shrinking their access to the food resources that have long provided the basis for their communities’ resilience.

The delayed and more drawn-out autumn freeze leaves communities isolated during a growing part of the year. That’s because they can’t use boats to travel to neighboring communities during this time but also can’t safely travel on top of the ice. At the same time, changing ocean temperatures are shifting food seasons. In Wales, Alaska, an Inupiat community that is the westernmost settlement in the United States, clams that once used to be harvested in the fall are now ready in summer.

“The way that the lower 48 relies on, say, citrus or grapes or the potato as garden food sources, the Bering Sea, when the sea ice comes, it is our garden,” said Mellisa Johnson, a guest editor on the report and a member of the Bering Sea Elders Group, which is made up of 38 tribal elders from the region. “It is our way of life.”

Similarly, whole Arctic communities have been built on permafrost. Because of climate change, that ground is now thawing. As it does, it causes roads to slump and houses to collapse.

But what happens in the Arctic doesn’t stay in the Arctic. Permafrost sequesters twice as much heat-trapping carbon dioxide as is currently in the atmosphere. As that ground thaws it releases that carbon into the atmosphere, exacerbating climate change. Researchers say that if too much permafrost thaws it will create a self-reinforcing cycle wherein thawing permafrost will lead to still more thawing permafrost, which in turn will make climate change worse. Recent observations of carbon flows in Alaskan permafrost have found that more carbon is being released than stored.

“The key question really remains as to whether the measurements in Alaska over a several year period are representative of the broader Arctic system of other regions in the Arctic where permafrost exists,” said Matthew Druckenmiller, a research scientist at the National Snow and Ice Data Center at the University of Colorado Boulder and one of the report’s editors. “If, in fact, it is, then we are seeing signs that the Arctic is really beginning to play that role as a large-scale feedback to the climate system.”

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Kendra Pierre-Louis is a reporter on the climate team. Before joining The Times in 2017, she covered science and the environment for Popular Science. @kendrawrites

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