Scientists have long said global warming will bring extreme weather.

It’s coming back.

The polar vortex that shocked the northeast with extremely cold days may bring more bitterly cold winters to North America, according to a new study.

The polar vortex is a massive system of swirling air that usually contains cold air around the North Pole. It has been shifting for decades, researchers found — but it has only recently become a household term, after it was blamed for causing record cold weather affecting some 200 million people in 2014.

According to the study, over the past 30 years, the polar vortex has weakened, in part due to Arctic sea-ice loss linked to human-caused climate change. That weakening has prompted a shifted toward Europe and Asia in February. This means unusually cold days may become more common in February and March, the Weather Channel reported. At the same time, Europe is facing warmer winters.

Scientists have long said global warming will bring extreme weather. This is what it looks like.

“Climate change can lead to extremes; it’s not like a regular change, everyone to the same extent at all times and places,” co-author Martyn Chipperfield, professor of atmospheric chemistry at the University of Leeds, told ClimateWire. “Despite the overall warming, you can get in places like the Northeastern U.S. extreme cold events. That’s consistent with climate change and global warming.”

A weakened vortex means cold Arctic air moves to lower latitudes, as happened in early 2014 and 2015. Some experts are reporting the polar vortex is already acting up this year, and that may point for a troubling winter……More Here