Global Warming

Study Links Arctic Melting, Extreme Weather

As ice at the North Pole disappears at an alarming rate, researchers are finding a link with recent bouts of extreme weather.

A new study suggests rapid warming in the Arctic may be altering weather patterns across the Northern Hemisphere.

But skeptics say the case is far from proven.

An “unbelievable amount of change” is happening in the Arctic, says Rutgers University climate scientist Jennifer Francis. Just half as much area is covered by ice compared to 30 years ago.

“And if you take into account the thickness as well, we’ve lost almost three-quarters of the volume of the sea ice,” she said.

At the same time, the Northern Hemisphere has seen some unbelievable weather in the last decade: Record-breaking heat waves and droughts in North America and Europe, and devastating floods in East Asia, to name a few.

Francis and colleagues went back through three decades of weather data and measurements of Arctic ice and snow cover in northern latitudes. They found that, “when there was less ice or less snow in any given year during the summertime, that that was more likely to occur at the same time as the occurrences of heat waves,” she says.

They published their findings in Nature Climate Change.

Francis says the loss of ice and snow are affecting the high-altitude wind patterns called the jet stream, which push weather patterns around the Northern Hemisphere.

The jet stream is driven by the difference in temperature between the Arctic and the temperate zones. The bigger the difference, the faster the jet stream flows.

But Francis notes that the Arctic is warming at least twice as fast as the rest of the planet.

“If we warm the arctic faster,” she said, “it’s decreasing the temperature difference and causing the jet stream to get weaker.”

Global greenhouse gas emissions will continue to melt the Arctic for decades to come.

“The loss of sea ice will go from 50 percent to 100 percent in the next 20 years or so, it will end up with an increased chance of more of these extreme weather events.”