All the pretty snow was blowing off the Front Range Chugach Mountains above Anchorage on Wednesday as the winds gusted over 80 mph, and the temperature climbed toward 40 degrees.
Welcome to Alaska’s new world of global warming, or is it climate change, or maybe just a “regime shift”?
Russian, Taiwanese and Greek scientists several years ago suggested the latter might be most in line with what is being witnessed here at latitude 61.
“It was found that the widely observed warming in the past century did not occur smoothly but sharply,” they reported in 2013.. “This fact is more pronounced at the latitude zone 30 degrees S – 60 degrees N during the years 1925/1926 and 1987/1988. We hypothesize that there were two major climate regime shifts in 1925/1926 and 1987/1988 years.”
They went on to argue that regional regime shifts are most consistent with what is being seen around the globe. These are not climate deniers making the case.
“Both natural and anthropogenic (ie. human) influences have caused the twentieth-century climate change,” observed Pavel Belolipetsky from the Russian Academy of Sciences and his colleagues. But highly visible, regional and local manifestations of climate shifts could be more complicated than just general, planetary warming.
“We wish to make it clear that detection of a regime shift is much easier than understanding the process or processes determining it,” they added. “So we are not speculating here about physical mechanisms and reasons for shifts. There are many possible variants as climate is a complex, nonlinear, dynamical system. The reasons may be intrinsic causes, some indirect solar or volcanic forcing, or (the) result of anthropogenic forcing.”
If you live in Southcoastal Alaska, it is hard to avoid the conclusion that a significant climate shift has been underway here for years. Temperatures on the Anchorage Hillside were into the high 30s on Wednesday evening with the winds gusting to hurricane force as a storm drove inland from the Gulf of Alaska.
The historic norm for this time of year, according to the National Weather Service, is 20 degrees with a high of 26 degrees and a low of 15. A day with an average temp in the high 30s is what would normally be expected for early October, according to Weather Service data.
The Alaska Center for Climate Assessment and Policy in an October report described the last five years in the state as a “period of dramatic climate change.” The shifts are most noticeable now and in the spring.
“The date when the state becomes 50 percent snow-covered is arriving a week later in October than it used it, and the spring “snow-off” date—when half the winter snow has melted—is arriving nearly two weeks earlier,” Climate.gov reported.
“Alaska has been warming twice as quickly as the global average since the middle of the 20th century,” the government website added. “Alaska is warming faster than any U.S. state. ‘Alaska’s Changing Environment’ notes that, since 2014, there have been five to 30 times more record-high temperatures set than record lows.
“On July 4, 2019, all-time temperature records were set in Kenai, Palmer, King Salmon, and Anchorage International Airport. Remarkably, Anchorage hit 90 degrees Fahrenheit; 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 summer was a change easily overlooked as a pleasant outlier. The changing storm patterns of traditional September-October weather systems coming in November and December is harder to dismiss.
What this means on a global scale hard to sort out.
A study published last week in Science Advances illustrated the difficulties of trying to predict the future. Paolo Scussolini from the Institute for Environmental Studies at Vrije University Amsterdam along with colleagues from Norway, Germany, Sweden, France, China, the United Kingdom and the U.S., examined prehistoric evidence of precipitation patterns during the Last Interglacial period 120,000 to 129,000 years ago to try to determine future moisture patterns.
As the planet warms, precipitation becomes as important as temperature. To oversimplify only slightly, warm, dry places become deserts, and warm, wet places become tropical rain forests.
“The Last Interglacial (LIG) is a primary target period for climate research because its climate holds one of the closest, although partial, analogies to possible climates of the coming decades and centuries,” the scientists wrote.
During the LIG, the evidence indicates the planet was slightly warmer than it is today, but it looked a lot different.
“Sea levels were several meters (9 to 10 feet) higher, implying that polar ice sheets were smaller,” the scientists wrote. “Yet, LIG greenhouse gas concentration was comparable to the preindustrial period, with carbon dioxide around 275 parts per million and methane around 700 parts per billion.”
Atmospheric carbon dioxide, the big concern of these times, is now at an unprecedented 407.4 ppm, according to Climate.gov. Why temperatures aren’t warmer and sea levels higher as a result is a question to which the answer is unknown.
It could be that the planet has yet to reach its tipping point.
“Much research has used geological evidence to estimate the temperature of the LIG in an effort to understand the thermal response to different orbital forcing constraining the internal feedbacks of the climate system,” Scussolini and his colleagues observed. “Compilations of proxies estimate that during the peak of the LIG (127 to 125 thousand years ago) climate may have been warmer than (present) by 2.0° ± 0.1°C over the whole Earth surface.”
The International Panel on Climate Change predicts that number won’t be hit until 2063 under the high and medium projections for carbon dioxide, primarily from the burning of carbon-based fuels. The low projection pushes the date out to 2100.
But the IPCC is projecting less than a meter of sea-level rise by 2100 – not several meters – in part due to the melting of glaciers and in part due to thermal expansion of seawater. But such changes are even harder to predict than the past is to explain.
It is not fully clear why the temperature went so high in the LIG with carbon-dioxide levels at only about two-thirds of what they are today and methane, an even more potent greenhouse gas, at less than half today’s level.
In the atmosphere, carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, chlorinated fluorocarbons and especially water vapor all play vital roles in letting the heat of solar rays pass through to warm the planet while preventing the escape of radiant heat from the same solar-warmed earth.
Without greenhouses gases, the earth would be the moon and nothing would be alive here.
The U.S. Environmental Protection Agency calculates methane is 28 to 36 more efficient than carbon dioxide as a greenhouse gas. But compared to today’s levels of methane, LIG leves of that gas were very low.
Atmospheric methane levels, like those of carbon dioxide, have been steadily increasing for decades. The National Oceanic and Atmospheric Administration (NOAA) puts the current level above 1858 parts per billion — more than two and a half times the level of the LGI.
Climate, which exists in the past and future, is a complicated puzzle. Weather, which exists in the here and now, is easy:
It’s hot or it’s cold. It’s wet or it’s dry. It’s windy or calm.
And sometimes it’s a combination of all three as it was Wednesday: warm, windy and by the time this story was finished wet with the Weather Service, which had posted a high-wind warning of gusts up to 80 mph early in the day later upping that to warn of “isolated gusts to 100 mph through the evening along the Upper Hillside.”