Warming climate could mean bigger blizzards, less snow
POSTED: Tuesday, February 26, 2013 - 9:10pm
UPDATED: Monday, March 4, 2013 - 10:27am
(CNN) -- OK, go ahead and get the "Where's my global warming?" jokes out of your system. With the U.S. Midwest trudging through its second blizzard in a week, we understand.
But while it may seem contradictory at first, scientists say bigger blizzards fit the pattern they expect to see from a changing climate.
The immediate meteorological cause of the back-to-back snowstorms is a colder-than-normal mass of air that's been hovering over the central United States, combined with an amped-up jet stream that's been dipping south from Canada. That makes conditions ripe for major snowstorms after a warmer-than-normal January for most of the Lower 48.
"Once you get into a pattern that sets up these storms, they can repeat themselves," National Weather Service Director Louis Uccellini told CNN.
The 21 inches that fell on Wichita, Kansas, in February just broke a monthly snowfall record set in 1913. Amarillo, Texas, saw 19 inches of snow on Monday alone, a total greater than its annual average and breaking a daily record of 12 inches that had stood since 1893.
As researchers are quick to point out, weather is different than climate. Weather is what happens today, while climate involves trends in temperature and precipitation over decades. But global average temperatures are up about 1.5 degrees Fahrenheit (0.8 degrees Celsius) since the 1880s, according to NASA, and because warmer air holds more moisture, a cold snap is likely to leave more snow on the ground.
"We have to keep in mind that in any given winter, you're going to have some big snowstorms," said Marshall Shepherd, a research meteorologist at the University of Georgia. "But we're loading the dice or stacking the deck toward more intense blizzards."
While the idea of long-term climate change is a controversial notion politically, it's accepted as fact by most researchers. The warming trend is expected to continue if heat-trapping carbon dioxide -- a byproduct of fossil fuels -- continues to build up in the atmosphere.
Sarah Kapnick, who studies snowfall patterns and climate at Princeton University, said the overall trend for snowfall in the western United States is down. Kapnick said her recent research points to more snow at high elevations and the Arctic, but the rest of the country would see less.
"The seasonal cycle is changing, and less of it accumulating," Kapnick said.
Shepherd said scientists can't attribute any one storm to the effects of climate change, any more than they can point to a single home run as evidence that a baseball player has been using steroids. "But when we get blizzards, they'll be stronger," he said.