Alaska’s last five years of climate change

I recently read an article by John Dos Pasos Coggin dated 10 October 1921, which reports the recent dramatic climate change. I quote:

“Vast, remote and largely still wild, Alaska stirs wonder in the hundreds of thousands who visit each year. With a land area of more than 570,000 square miles and the longest coastline of any state, Alaska is larger than Texas, California and Montana combined. It contains 17 of the 20 highest peaks in the United States, including Denali, the highest peak in North America. It is home to an estimated 100,000 glaciers. Its natural monuments – mountains, tundras, glaciers, lakes, seas – are of such gargantuan scale that the environment can seem immutable”.

The climate for Alaska is changing, due to human-caused global warming. The effects are widespread and potentially dangerous. Alaska’s ten coldest years on record all occurred before 1980. Meanwhile, nine of its ten warmest years on record have occurred since 1980. Rick Thoman and John Walsh of the Alaska Center for Climate Assessment and Policy authored the report, which describes major changes in temperature, sea ice, glaciers, permafrost, plants, animals and oceans. Some of the content comes from Walsh’s own research, partially funded by the Climate Observations and Monitoring programme at NOAA’s Climate Program Office, in which he developed climate indicators to monitor variables such as tundra greening, growing season warmth, storminess and sea ice.

“Our hope,” said Rick Thoman, Alaska Climate Specialist, in a recent interview with Climate.gov, “is that the style and presentation will allow any interested citizen to get a feel for what has been happening in recent years. By focusing solely on observed changes (or lack of changes), we avoid the confusion that can result in mixing ‘what has happened’ with ‘what might happen’ through climate model projections.” The date when the state becomes 50% snow covered is arriving a week later in October and the spring ‘snow-off’ date, when half the winter snow has melted, is arriving nearly two weeks 
earlier.
Another unique feature of Alaska’s changing environment is its anecdotal observations from rural areas of Alaska. Climate change threatens dire consequences for many Alaska Native villages in remote areas, where subsistence hunting, fishing and gathering are critical to livelihoods.

On 7 April 2017, Miki Collins of Lake Minchumina observed that the snow melt was earlier than usual. “Dog team hauling gas during spring melt,” said Miki in the report. “Gravel is exposed and grinds on sled runners, which is a problem especially when hauling heavy loads.”

It is important to monitor Alaska’s changing climate with precision and diligence, as the pace of change can be rapid. According to the Fourth National Climate Assessment, Alaska has been warming twice as quickly as the global average since the middle of the 20th century. Alaska is warming faster than any USA state.

Alaska’s Changing Environment ^[1] notes that, since 2014, there have been five to 30 times more record-high temperatures set than record lows. Remarkably, Anchorage hit 90°F; the average summer temperature in Anchorage is normally in the mid-sixties. July 2019 was the hottest month in recorded history for the state. June 2019 was the second 
warmest on record.

The extremes on land are surpassed by what is going on in the sea. Alaska’s Changing Environment affirms: “Nothing in the Alaska environment is changing faster than sea ice.” Today, typical summer ice extent on the Chukchi Sea is only 10% of what it was in the early 1980s and the Beaufort Sea ice-over usually occurs two to three weeks later in the fall than in past decades. In 2018 and 2019, late winter ice coverage in the Bering Sea’s Alaska waters was significantly lower than any winter in the last 170 years. Surface waters along Alaska’s west coast were 4-11°F warmer than average this summer.

Alaska climate monitoring is critical to USA economic strength. Alaska’s commercial fishing industry is the most productive such industry in the USA, producing more harvest volume than all other states combined. Alaska annually exports more than one million metric tons of seafood; in 2016, Alaska seafood was sold in 105 countries. The Alaska seafood industry generates US$12.8 billion (approximately £10.44 billion) in annual economic output for the USA; climate change and ocean acidification put all the state’s fisheries at risk.

“Alaska is built for seasonal cold,” said Rick. “Whether it is modern housing, transportation in the vast roadless areas of the state or traditional food storage methods, warming is disruptive and brings stress, risk and hardship to many.”

References
1. R Thoman and J E Walsh, ‘Alaska’s Changing Environment: Documenting Alaska’s physical and biological changes through observations’, 2019.