Much has been made about the well-above-average temperatures the Great White North has experienced this year and during the winter of 2015. For example, The Washington Post ran a story on December 20 titled “Pre-Christmas melt? North Pole forecast to warm 50 degrees above normal Thursday.”
Undoubtedly, the most vocal and least careful proponents of the theory that human use of fossil fuels is causing climate change will seize on this isolated fact as proof anthropogenic climate change is occurring. Some of them already made such claims in late November, when the temperatures in the Arctic were also well above average for that time of year.
In a November Live Science story, University of Rutgers professor Jennifer Francis said:
The Arctic has been in uncharted territory pretty much all year long, ever since last fall. … The loss of the sea ice, the increased melting of the Greenland Ice Sheet, the thawing of permafrost, the changes in the weather patterns, the rising sea level – it’s all consistent with our expectations for the response of the climate system to increases in greenhouse gases. It’s been totally expected.
The problem is, as a careful reading of The Washington Post story reveals, while temperatures in the Arctic are relatively high, high temperatures, while not the norm, are also not unusual. That’s because the kind of weather patterns that have caused the past two years of warmth have happened once or twice each decade at least since the 1950s, according to a recent paper that will appear in the influential journal Nature.
The Weather Constant Is Change
In the middle of 2016, the world emerged from an unusually powerful El Niño, which had raised ocean temperatures well above average. The El Niño has been replaced by a La Niña, which has contributed to swiftly cooling land temperatures, but it takes time for the latent heat contained in the ocean to dissipate.
Simultaneously, snow swept over Eurasia at the fastest pace on record in October. This snowfall caused cooler temperatures that, when combined with an extreme high-pressure system that formed in Siberia in October and persisted for more than a month, shifted the jet stream, pushing milder air toward the Arctic. The jet-stream shift, combined with low-pressure systems in the Pacific and Atlantic, kept temperatures relatively high and prevented extensive sea ice from forming. The low sea-ice levels further contributed to warmer temperatures.
Low sea ice and high Arctic temperatures are not a consequence of human-caused global warming. They result from the same natural factors that have controlled weather in the Arctic and around the world since the beginning of time. Nature, not human-produced greenhouse-gas emissions, is responsible for the “melting” North Pole, as well as the deep freeze that has been occurring over the past month throughout much of Asia, Siberia, and even parts of the United States.
As Ryan Maue, a meteorologist with WeatherBell Analytics, told The Washington Post, the large Arctic storms that drew mild air into the Arctic in 2015 and 2016 are “part and parcel of Atlantic weather variability.”
In an October 2016 Nature Geoscience study, researchers running climate-model simulations against 600 years of climate records “found no evidence of Arctic sea-ice loss having impacted Eurasian surface temperature. … We conclude that the observed cooling over central Eurasia was probably due to a sea-ice-independent internally generated circulation pattern.”
This finding was seemingly confirmed in an October Geophysical Research Letters paper, which finds shifts in large-scale, regional Atlantic and Pacific Ocean circulation patterns are likely responsible for both sea-ice loss in the Arctic and more frequent cold winters in Europe recently.