Scientists Are Clear: Big Winter Storms Influenced by Warming Planet
Warmer oceans and atmosphere likely contributing to the two to three feet of snowfall expected to blanket much of the Northeast
As Nor'easter Juno clobbered much of the northeast United States with heavy snow, surging tides and hurricane-force winds on Tuesday, scientists have been quick to note that such increasingly intense weather patterns are simply part of the "new normal" living on a warmer planet.
As of 6:32 AM EST on Tuesday, parts of New York's Long Island, coastal Massachusetts and Rhode Island were already reporting over 20 inches of snow. Meanwhile, communities along the coast, particularly on the Cape Cod peninsula, warned of "significant flooding" and reported wind gusts up to 75 miles an hour.
— Dave Malkoff (@malkoff) January 27, 2015
The nor'easter, expected to continue throughout the day as it moves north along the New England coast, has been described as "historic" with many areas expecting as much as three feet of snow. Such conditions come as no surprise to many climate scientists due to increasingly warmer ocean and atmospheric temperatures as a result of human-driven climate change.
— Matthew Cappucci (@MatthewCappucci) January 27, 2015
"Big snowfall, big rainstorms, we've been saying this for years," University of Illinois at Urbana-Champaign climate scientist Don Wuebbles told National Geographic. "More very large events becoming more common is what you would expect with climate change, particularly in the Northeast."
As National Geographic explains, the northeast United States is the "big winner in the 'extreme precipitation sweepstakes' dealt out by global warming." Severe blizzards—such as the one pounding the region on Tuesday—and rainstorms have increased by more than 70 percent in the past six decades in the Northeast, according to the 2014 National Climate Assessment report (pdf).
Further, these examples of "extreme precipitation" now release 71 percent more precipitation—as evidenced by other recent events such as the 2012 Hurricane Sandy, which flooded Manhattan, or the Blizzard of 2013, during which almost 25 inches of snow dropped on Boston.
"The U.N. Intergovernmental Panel on Climate Change has found that nor’easters like this one may grow stronger [with] human-caused climate change, as they are driven by the contrast between cold Arctic air masses and ever-warming ocean surface temperatures," Penn State climatologist Michael Mann told the Washington Post.
"We also know that ocean surface temperatures off the U.S. east coast right now are unusually warm, and there is no doubt that a component of that anomalous warmth is due to human-caused climate change," Mann added.
According to Dr. Kevin Trenberth, former head of the Climate Analysis Section at the National Center for Atmospheric Research, sea surface temperatures are more than 2° F above normal over huge expanses (1000 miles) off the east coast.
What's more, with warmer atmospheric temperatures, the air can hold more water vapor, increasing the possibility of more precipitation. Trenberth notes that current water vapor in the atmosphere is about 10 percent higher then average. About half of these above-average conditions, Trenberth says "can be attributed to climate change."
As Trenberth has previously explained, "All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be."
While climate change is not the direct cause for Tuesday's storm, it is likely contributing to the car-high snowdrifts and howling winds. Further, as the planet grows increasingly warmer, these "once-in-a-century" blizzards will become much more frequent.
Throughout the day on Tuesday, the Weather Underground is maintaining a live blog of conditions and updates while some of the millions of people impacted by the storm, including weather services, are sharing photos and other snow day anecdotes online under the hashtag #Juno.