A record heat wave across Alaska and much of the Arctic is thawing tundra and sucking moisture out of circumpolar forests and peat bogs, triggering wildfires and choking, black smoke that are starting earlier, burning hotter, and spreading farther north than they have before.
All of those observations are “in line with what climate models have long suggested would happen as sea ice dwindles and ocean and air temperatures rise,” InsideClimate News reports. “Global warming has been thawing tundra and drying vast stretches of the far-northern boreal forests, and it also has spurred more thunderstorms with lightning, which triggered many of the fires burning in Alaska this year.”
With more than 1.2 million acres (485,000 hectares) already burned this year, and the danger expected to continue for weeks, 2019 is already one of Alaska’s three biggest fire years on record, InsideClimate notes. “A region of Alaska about the size of California has been sizzling under an intense, record-length heat wave for weeks. And it isn’t just the land that’s warming: the northern coast is losing its sea ice about two months earlier than average, and ocean surface temperatures are as much as 9.0°F/5.0°C above normal in the Chukchi Sea.”
This year, the combination of all the state’s monthly average temperatures between July and June went above freezing for the first time in the 95-year record, and the statewide average temperature was 7.9°F/4.4°C above average. The state’s biggest city, Anchorage, just finished a 12-day stretch with an average temperature of 81°F/27°C, a level the city hit on only 17 days in the previous 67 years, according to climate scientist Brian Brettschneider of the International Arctic Research Center (IARC). The temperature on July 4, at 90°F, broke the city’s all-time record by five degrees.
“We keep our doors and windows closed at night to keep the smoke out,” Brettschneider aid. “This morning I got up and it was 80 degrees in the house.”
“It really is unprecedented, a word we should not use lightly,” wrote climate researcher Thomas Smith of the London School of Economics and Political Science, who warned the June fires in the Arctic could be a sign of a climate tipping point.
“It may be that in most previous years, temperatures have never been warm enough to drive off moisture from the winter frost and snowpack,” he wrote. “The ground is likely covered in mosses that act as a sponge, staying moist all summer long before freezing again in winter. But now that sponge is drying out.”
InsideClimate documents the new threats facing Alaska and the wider region, with several recent studies showing severe health risks in the southern part of the state and Fairbanks seeing public health warnings in response to heat, smoke, and airborne soot. In 2016, a paper in the Bulletin of the American Meteorological Society showed climate change increasing the risk of extreme fire seasons in Alaska by 34 to 60%, with warmer temperatures making trees, grass, shrubs, and tundra more flammable unless warming was offset by wetter conditions.
“A rule of thumb is that, for every 1.0°C temperature increase, you need a 15% increase in precipitation to offset the drying effects,” said IARC Deputy Director Scott Rupp. “In interior Alaska we have seen increases of 2.0° to 3.0°C over the past 40 years,” without enough added moisture to offset it.
Mark Parrington, a senior scientist with the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Copernicus Atmosphere Monitoring Service, said satellite monitoring earlier this month confirmed smoke emissions and fire intensity in June that were unprecedented for Alaska.
“I am concerned about how bad it can potentially get in terms of the size of the fires and the impact of smoke pollution in the Arctic, which is often thought of as a remote and pristine environment,” he told InsideClimate. “We know that the Arctic climate has been changing at a much faster rate than the rest of the world, and it is worrying to think that we could now be witnessing the effect of this directly in the Arctic Circle.”
While the state’s scientists worry about the future of research by the state university system, following a veto by Republican governor Mike Dunleavy that would cut the system’s by 41%, the chair of atmospheric sciences at the University of Alaska Fairbanks talked to reporter Bob Berwyn about the complexity of the Arctic climate challenge.
“What keeps me up at night is that the climate problem is a complex problem. It’s not just a science problem, it’s a social problem and a political problem,” said climate variability specialist Uma Bhatt. “I should be doing climate research rather than worrying about whether the university will be standing.”
She added that climate change concern is on the rise across the state.
“I talk to a lot of people in rural areas, and they are concerned about how ecosystem services are changing,” she said. “There is a notable population in Alaska who live a subsistence lifestyle, hunting and fishing, and that is changing. It’s changing fast, within a generation, so the knowledge about things like hunting in the coastal ice will have to shift very quickly.”