When you talk to climatologists about 2016, the phrase “mind-boggling” comes up a lot.
“For crying out loud, yesterday it was 36 degrees in Barrow, Alaska, in the middle of winter,” said Rick Fritsch, a climate expert for the National Weather Service in Juneau. “If that doesn’t make the point, I don’t know what does. That’s not supposed to happen, at least not in the world I used to live in.”
Last year, Alaska cities and towns from Utqiagvik to Ketchikan saw unprecedented warmth. In Utqiagvik, formerly known as Barrow, temperatures averaged 7.1 degrees above normal. In Kotzebue, the average was 6.8 degrees above normal. In Juneau, it was 2.7 degrees beyond the norm.
“It’s really quite stunning to see that Nome has its first year with an average temperature above freezing,” said Rick Thoman, a climatologist with the National Weather Service in Anchorage.
One year doesn’t make a trend. Climate is the sum of decades or centuries of annual observations, not one year alone.
“By itself, it doesn’t mean very much; it’s one year,” Thoman said.
But 2015 was Juneau’s hottest year before 2016. The year before was one of the 10 warmest since modern recordkeeping started in 1936. Six of Juneau’s 10 warmest years have come since 2000, and none is earlier than 1981.
The trend is clear: As carbon dioxide levels rise in the world’s atmosphere, Alaska is warming quickly. The climate is changing.
The capital city isn’t about to turn into a desert, its evergreens replaced with cacti.
In fact, warmer weather might even be nice, Fritsch said. The problem is everything else that comes along with it. We can feel warmer temperatures, but we can’t feel the changes also happening beneath ocean waves or in the land beneath our feet.
“When I look at it, this is like, oh, this is quite scary,” he said. “I think the implications for the ecosphere are far greater than the sense-able change in terms of the temperatures. It’s going to be huge, I think.”
At the Mendenhall Glacier, John Neary and the employees of the U.S. Forest Service have a tall task. Each summer, they talk to hundreds of thousands of visitors about climate change.
“It’s very clear this glacier is receding up the valley,” Neary said, explaining the pitch that the glacier’s employees tailor to each visitor. “The atmosphere is warming, and here is the result, and humans are the cause of this, and it’s not just a natural cycle.”
While each interpreter uses different words, each comes back to a particular subject: carbon dioxide.
Since the 19th century, carbon dioxide has been known as a greenhouse gas. It traps and retains heat better than the other gases that make up our atmosphere. The more carbon dioxide in a gas mixture, the better that mixture can retain heat.
Since March 1958, carbon-dioxide levels have been measured at the Mauna Loa Observatory in Hawaii. In that time, those levels have risen from 316 parts per million to 404 parts per million. According to measurements taken from a variety of geological sources, carbon-dioxide levels have been below 300 parts per million for 400,000 years — until 1950.
There isn’t a straight-line link between carbon-dioxide levels and the weather outside your window.
Thoman, with the Weather Service in Anchorage, said it’s fair to think of a year’s Alaska weather as the sum of four dice: one representing sea ice, one representing ocean temperature, another representing snow cover and the fourth representing carbon-dioxide levels.
Roll all sixes, and you’ll have a record warm winter; roll all ones, and you’ll have a frigid one.
Rising carbon levels change the faces of that fourth die. Instead of one through six, its faces might show two through six, with three duplicated.
Weather isn’t climate: The dice aren’t rolled just once; they’re rolled again and again.
What’s more, the more you roll high numbers, the greater the chance that the faces of the other dice will change, too.
“As CO2 levels rise, over the long term, ocean temperatures have nowhere to go but up, and sea ice levels have nowhere to go but down,” Thoman said. “Eventually, the faces of the sea surface temperatures and the sea ice (dice) … those will all trend towards the high.”
With less white snow and white ice to reflect sunlight, the ground warms more quickly and temperatures rise. It’s a feedback effect: Warm temperatures create conditions for still-warmer temperatures later.
Throughout the Interior and the North Slope, the ground is permanently frozen more than a few feet below the surface. Temperatures are so low that the earth never warms enough to melt this permafrost.
As Alaska warms, that’s beginning to change.
Buildings built atop permafrost must be renovated or strengthened as it thaws and sags. Roads have to be reconstructed.
The bigger problem is what happens when the permafrost decays.
Anyone who owns a dog knows the disgusting backyard buildup that happens during winter. Cold weather and snow kills the bacteria that ordinarily breaks down dog doo. Anything your dog releases will stay frozen until spring. When it melts, it creates a stinky and disgusting problem.
The same is true of permafrost, which contains piles of frozen organic matter.
When something decays, it releases greenhouse gases that contribute to warming.
“If you open the freezer door, you thaw permafrost soil that’s been frozen for a long time, and the organic matter in it is decomposed by microbes,” said University of Alaska Fairbanks researcher Katey Walter Anthony in late August.
Billions of tons of permafrost underlie the northern regions of North America, Asia and Europe. If they are melted by rising Arctic temperatures — as seen in 2016 — methane and carbon dioxide will enter the atmosphere in huge amounts.
“As such, the Earth’s climate is sensitive to the escape of even a small fraction of this methane,” Anthony and her co-authors wrote in a 2012 paper.
In a 2016 followup, she and her co-authors concluded that permafrost hasn’t yet begun to contribute in a big way to climate change, but that doesn’t rule it out in the near future.
At sea, the effects are already happening.
At the Ted Stevens Marine Research Institute in Auke Bay, Mike Sigler has been leading a team that studies what happens when rising carbon-dioxide levels in the atmosphere affect the ocean.
“Carbon dioxide has two properties: one is to trap heat in the atmosphere, and the other is that carbon dioxide dissolves into the ocean and changes the ph level,” he said.
Carbon dioxide combines with ocean water to create carbolic acid. That’s deadly to shellfish and crabs, which rely on a substance called calcium carbonate to create their shells. Calcium carbonate — the same stuff that makes up limestone — is dissolved by carbolic acid.
“We can see that ocean acidification is having an impact on these minerals,” said Jessica Cross, a chemical oceanographer with the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory in Seattle.
“We’re starting to understand this threat, we’re starting to model what this might mean for the future,” she said.
What it means is many fewer crab and shellfish.
“With red king crab, it’s all doom and gloom,” researcher Robert Foy told the Seattle Times in 2013.
That year, Foy published the results of his research into acidification’s effects on crab. They show that as the ocean acidifies, crab have a hard time surviving. By 2050, according to NOAA estimates, acidification will cost the red king industry 1,000 metric tons of catch per year. By 2100, unless something else changes, it’s likely to end the industry.
Here in Southeast Alaska, the situation is more complicated, said Wiley Evans, a researcher at the British Columbia-based Hakai Institute. Southeast Alaska’s shellfish hatcheries are already coping with an acidifying ocean, but in the long term, flows from the region’s rivers confuse the models used for long-term predictions.
The biggest impact is likely to fall upon phytoplankton, the microscopic organisms that form the base of the food chain in the Gulf of Alaska.
Phytoplankton consume carbon dioxide, but they also consume nutrients in the upper portion of the ocean.
Increased carbon dioxide levels give them more fuel to bloom, but that can also cause them to eat themselves to death quickly — before salmon have time to feed.
“They’ll run out of food, they’ll die, they’ll sink to the bottom before the fish have an opportunity to come and eat,” Cross said.
The details are still being studied, but Sigler said there’s one takeaway that Alaskans can make now: “The point is that carbon dioxide doesn’t just go into the air; it goes into the water, and it has effects there that are not visible to you or I.”