Forty years ago scientists said global cooling was causing the polar vortex to dip into lower latitudes. Now they’re blaming climate change.

A new study in Nature says Climate Change may force the polar vortex to dip down more often, triggering bone-chilling winters in Europe and North America. Many of the claims of an overheated Earth dissipate during winter as temperatures plummet and heating bills rise. Yet the authors write that as the Arctic warms and more sea ice melts, additional ocean water is exposed, absorbing the sun’s warmth.

The excess warmth then gets released over a longer time period, interrupting the polar vortex and pushing it down into lower latitudes. Sea ice, however, reflects the sun’s rays back into space, causing temperatures to plummet during the winter. That’s what happened in early 2014 and 2015 when Arctic air bullied its way toward more temperate regions.

Source: Thomas Richard,