As most of you know, Buffalo has never hit 100 degrees since our records began in 1871, having touched 99 just once. A town called Verkhoyansk in Siberia now has us beat, having reached 100.4 degrees on June 22. This town is north of the Arctic Circle, and is the first location anywhere north of the circle to reach or surpass 100 degrees. The reading was 32 degrees above average for that location.
Verkhoyansk has been called the north pole of cold, and is known for its especially wide range of annual temperatures. Its average January temperature is -49 and its July average is 62. Knowing that, you can imagine why a reading of 100.4 would be more than unusual. On the map, you can see the town is well inland from the Arctic Ocean. It has no marine layer affecting its climate. Moist marine air from Lake Erie is the reason Buffalo hasn’t hit 100, nor has Tampa or Miami Beach.
One could be tempted to put the entire onus for this unprecedented heat on our mean warming climate. As models predicted decades ago, warming would be faster in the Arctic than any other part of the earth. It has, in fact, proceeded at a pace that twice exceeds the mean rate of global warming. The feedback cycle, simplified, began with the earlier warming of the 80s began accelerating the melting of Arctic sea ice. When sea ice melts, its highly reflective white surface is replaced by dark ocean waters, which absorb far more solar energy, warming the waters and the region. When winter comes, there is a shorter freeze season, and much of the new arctic ice returns in thinner sheets, more vulnerable to earlier melting in the spring. This feedback mechanism isn’t quite linear, but over the last four decades it has been inexorable, lending more warmth in varying degrees to virtually all of the Arctic in the warming months.
But what we have now in Siberia is more likely a hybrid of shorter term weather patterns blended with the longer term warming climate. On the scale of weather, the warming in Siberia began to accelerate in January, though it was hardly confined to Siberia.
Siberia and other parts of the Arctic had already experienced two previous winters of extraordinary warmth, with this newest cycle extending through the last six months. From January through May, the mean temperature in parts of Siberia ran a striking 13 degrees above average, as seen in this NOAA graphic.
But not all of this warming can be solely attributed to a warming climate. There is still a matter of the normal impacts of shorter term weather variability to consider in a newer sub-discipline of climate science called attribution science.
“We have an overall warming trend, which is primarily a response to increasing greenhouse gas concentrations in the atmosphere,” Anthony Broccoli, a climate scientist at Rutgers University, told Mashable. "And on top of these rising background temperatures, there is the normal variability in weather, which this year has turned out to be quite warm over Siberia.”
The complexities of filtering out which part of warming is due to climate and which part is more related to shorter term weather is a big part of attribution science. Flavio Lehner, a National Center for Atmospheric Research climate scientist, has calculated an estimate of climate’s causation in the incredible Siberian warmth for Mashable. Lehner “estimated that of the seven degrees C of above average temperatures in Siberia this year, between two to 2.3 C came from human-caused warming of the planet. So climate change certainly had a strong influence, but not quite as robust as the weather.”
Because 19 of the last 20 years have been the warmest globally on record, we know the warming climate, rather than weather cycles, is due to the burning of fossil fuels and global agricultural practices – human activity. As I’ve written in past articles, peer-reviewed research is conclusive that the world would have been cooling for more than the last 100 years, likely headed toward an ice age if it were not for human activity.
The impacts of Arctic warming are many, and one of the most notable is rising sea levels tied to glacial melting in the region (i.e. Alaska glacial shrinkage) and, even more importantly, the massive reduction in Greenland’s ice mass (the melting of sea ice, like melting ice cubes in a glass, doesn’t directly cause rising waters, although warming ocean waters do expand in volume).