An alarming heatwave in the sunless winter Arctic is causing blizzards in Europe and forcing scientists to reconsider even their most pessimistic forecasts of climate change.
Although it could yet prove to be a freak event, the primary concern is that global warming is eroding the polar vortex, the powerful winds that once insulated the frozen north.
The north pole gets no sunlight until March, but an influx of warm air has pushed temperatures in Siberia up by as much as 35C above historical averages this month. Greenland has already experienced 61 hours above freezing in 2018 – more than three times as many hours as in any previous year.
Seasoned observers have described what is happening as “crazy,” “weird,” and “simply shocking”.
“This is an anomaly among anomalies. It is far enough outside the historical range that it is worrying – it is a suggestion that there are further surprises in store as we continue to poke the angry beast that is our climate,” said Michael Mann, director of the Earth System Science Center at Pennsylvania State University. “The Arctic has always been regarded as a bellwether because of the vicious circle that amplify human-caused warming in that particular region. And it is sending out a clear warning.”
The question now is whether this signals a weakening or collapse of the polar vortex, the circle of strong winds that keep the Arctic cold by deflecting other air masses. The vortex depends on the temperature difference between the Arctic and mid-latitudes, but that gap is shrinking because the pole is warming faster than anywhere on Earth. While average temperatures have increased by about 1C, the warming at the pole – closer to 3C – is melting the ice mass. According to Nasa, Arctic sea ice is now declining at a rate of 13.2% per decade, leaving more open water and higher temperatures.
Some scientists speak of a hypothesis known as “warm Arctic, cold continents” as the polar vortex becomes less stable – sucking in more warm air and expelling more cold fronts, such as those currently being experienced in the UK and northern Europe. Rohde notes that this theory remains controversial and is not evident in all climate models, but this year’s temperature patterns have been consistent with that forecast.
Longer term, Rohde expects more variation. “As we rapidly warm the Arctic, we can expect that future years will bring us even more examples of unprecedented weather.”
David Llewellyn-Smith is Chief Strategist at the MB Fund and MB Super. David is the founding publisher and editor of MacroBusiness and was the founding publisher and global economy editor of The Diplomat, the Asia Pacific’s leading geo-politics and economics portal.
He is also a former gold trader and economic commentator at The Sydney Morning Herald, The Age, the ABC and Business Spectator. He is the co-author of The Great Crash of 2008 with Ross Garnaut and was the editor of the second Garnaut Climate Change Review.
