90 degrees in Alaska: Extreme heat is irreversibly altering the last frontier
BY TIM LYDON, OPINION CONTRIBUTOR — 07/09/19 08:30 AM EDT - The Hill
Alaska just experienced yet another remarkable heat wave, with temperatures in Anchorage soaring to a record-shattering 90 degrees. It was an extreme weather event that made national news. But it was also part of a steady warming trend that is irreversibly altering Alaska, likely with global implications.
“This (heat wave) is one to remember,” says Rick Thoman, climate specialist with the Alaska Center for Climate Assessment and Policy. Thoman explains that the heat resulted from a “classic set-up” of high pressure aloft, which commonly brings warmth to Alaska. But, Thoman says, this event occurred against a backdrop of warm ocean temperatures and other factors related to climate change, which can super-charge otherwise normal weather events.
And this was anything but normal weather. Records were obliterated across a wide swath of Alaska, with Anchorage and other locations reaching all-time high temperatures over the Fourth of July weekend. It stoked large wildfires, extreme fire danger, and extraordinary melting of ice and snow. It also came on the contrails of the hottest June ever recorded in Anchorage, which brought an additional string of days above 80 degrees.
The heat coincides with the height of Alaska’s tourism season, when people flock to the “last frontier” to experience America’s unmarred wilderness landscape. But this year’s visitors find unnatural heat and acrid, smoke-filled air that blots out our usually crisp mountain scenery. They see beleaguered glaciers that are hemorrhaging fresh water into dangerously swollen creeks. They are chagrined that firework displays are canceled due to extreme fire danger. But visitors may be missing the bigger picture.
“This heat wave is just the latest in a seemingly unending saga of warming in Alaska,” says Thoman.
Only a few months ago we experienced our hottest March on record, which brought temperatures as high as 40 degrees above average and abruptly ended Alaska’s normally long snow season. Records were set for earliest break-up of ice on major rivers and an unprecedented loss of sea ice, especially in the Bering Sea of western Alaska. At least eight people drowned in separate incidents related to abnormally thin ice.
Over my nearly three decades in south-coastal Alaska, temperatures have steadily risen. But the change accelerated in 2013. That’s when a massive marine heat wave brought exceptional warmth to the northern Gulf of Alaska. It became known as “the blob” and lasted over two years.
Subsequent marine heat waves flared up around the Aleutian Islands and the Bering Sea, and now appear part of a more permanent change to Arctic waters. Research shows they have contributed to a dramatic decrease in Alaskan cod harvests, the starvation of tens of thousands of puffins, murres and other seabirds, as well as unusually high mortalityamong fin and humpback whales. This year’s death of over 170 gray whales may also be tied to Alaska’s warming oceans.
Record-breaking heat is now the norm in Alaska. It is driven in part by the feedback loops scientists have warned for many years will accompany anthropogenic climate change. For example, the present extreme dearth of sea ice in the Bering and Chukchi seas creates expansive areas of newly opened ocean, which transfer significant heat into the atmosphere. It fuels record heat waves, which further warm ocean waters and help delay subsequent sea ice formation. In turn, temperatures steadily rise in what Thoman calls “the escalator of climate change.”
The changes disrupt life in Alaska. According to the Government Accountability Office, declining sea ice and melting permafrost have put at least 31 communities at risk, with erosion imperiling homes, roads and drinking water sources. Three villages — Kivalina, Newtok and Shishmaref — face the traumatic realization that they must relocate soon or cease to exist.
In an added hardship, disappearing ice cuts off access to traditional hunting and fishing grounds, and the warming ocean is changing where fish and marine mammals can be found. This has real nutritionalconsequences in a land where many residents still rely on subsistence hunting and fishing. Commercial crab, cod and pollock fleets also wrestlewith the changes.
Warming in the Arctic may also be impacting global weather, as Scientific American described in 2018. Specifically, Arctic warming is changing the global temperature gradient, possibly contributing to greater meanders in the jet stream. This summer, such meanders have played a role in anotherround of record-setting heat in Europe and a recent Russian hot spell that sent Arctic temperatures rocketing to 84 degrees. Thoman says these possible global implications of Arctic warming are now an area of “active research.”
In a welcome relief, the heat in Alaska is subsiding this week. But temperatures are forecast to remain above normal. In other words, after the latest weather extreme we are back to riding steadily upward on the escalator of climate change.