Snow may still be on the ground in parts of northern New England. But records show that overall snow cover is disappearing faster and earlier in the Northern Hemisphere.
That could be a big problem for our climate, said GBH meteorologist Dave Epstein.
“The faster snow and ice are disappearing, the more that part of the planet is heating up, the more we see greater effects of climate change,” Epstein told Morning Edition co-host Jeremy Siegel on Thursday.
Officially, snow cover refers to when an area has one inch of snow on the ground. Epstein noted that snow cover usually disappears relatively early in southern New England.
“Most years, snow cover is kind of disappearing during the month of March. It would be an unusual year if we still had snow cover in April,” he said, noting that it's a different story in northern New England, where it's not unusual for snow cover to linger a bit longer.
While New Englanders may welcome the snow’s departure each spring, in some parts of the world — like Canada, northern parts of China, Russia and Scandinavia — there’s a big benefit when snow cover leaves later, in April, May and even June.
“Up there you want that snow cover to be around later in the season,” he said.
Snow cover has a big impact on our climate, Epstein said, because that white reflects solar radiation. If the landscape turns brown without snow, it will absorb the sun’s radiation rather than reflect it.
“That's heating things up exponentially faster. So you start removing snow cover earlier in the season, you start heating the planet up faster, and then the ground starts warming up,” he said. “You start melting permanent frost — which is in the ground — and you continue to exacerbate the climate change system, and we continue to warm up.”
Ultimately, the snow cover in these warming global spots will impact us here in New England, a region known as the “mid-latitudes,” as the regions warm up and affect the jet stream.
“The impacts of what's going on to our north will be affected down here,” he said. “Summers around here are much warmer, as it's just not as cold anymore. To the north, we don't have the cold air to come down … later on in the season, late spring and throughout the summer.”
