If ever there were a silver lining to global warming, it might be the prospect of milder winters. After all, it stands to reason that a warmer climate would generate less snow.
But a new MIT study suggests that you shouldn’t put your shovels away just yet. While most areas in the Northern Hemisphere will likely experience less snowfall throughout a season, the study concludes that extreme snow events will still occur, even in a future with significant warming. That means that, for example, places like Boston may see less snowy winters overall, punctuated in some years by blizzards that drop a foot or two of snow.
Study author Paul O’Gorman is an associate professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences. He said:
In some regions, it is possible for average snowfall to decrease, but the snowfall extremes actually intensify.
O’Gorman studied daily snowfall across the Northern Hemisphere using 20 different climate models, each of which projected climate change over a 100-year period, given certain levels of greenhouse gas emissions. He looked at both average seasonal snowfall and extreme snowfall events under current climate conditions, and also following projected future warming.
Not surprisingly, O’Gorman found that under relatively high warming scenarios, low-elevation regions with winter temperatures initially just below freezing experienced about a 65 percent reduction in average winter snowfall. However, in these same regions, the heaviest snowstorms became only eight percent less intense. In some higher-latitude regions, extreme snow events became more intense, depositing 10 percent more snow, even under scenarios of relatively high global warming. O’Gorman said:
You might expect with a warmer climate there should be major changes in snowfall in general,” O’Gorman says. “But that seems to be true to a greater extent for average snowfall than for the intensities of the heaviest snowfall events.
O’Gorman has published the results of his study this week in the journal Nature.
Anthony Broccoli, professor of environmental sciences at Rutgers University, notes that the study’s results may have implications for the public perception of climate change. For example, while people may be tempted to think that a winter with several extreme snowstorms calls global warming into question, that may not be the case. He said:
We often hear people claim that a big snowstorm is evidence that the climate is not warming, but these results make it clear that such storms do not provide much evidence about a changing climate. Those of us who live in the Northeast will likely continue to see occasional heavy snowstorms, especially in midwinter when temperatures are at their lowest.