How Warm Is Global Warming?

Dear EarthTalk,

How is it said that we are “losing winter” because of climate change? It didn’t seem so last winter when it even snowed in places it had never snowed before.—Peter Kim, Duxbury, Massachusetts

EarthTalk: The effects of global warming manifest themselves differently in different locations, and winter is no doubt getting shorter and warmer across New England, the Canadian Maritimes, and Northern Europe. 

In New England, average winter temperatures have increased 44˚F since 1970. The years 2006 and 1998 were the first and second warmest years on record in the U.S. since we started counting, with the last eight five-year periods the warmest in history. According to the National Climatic Data Center, that warming has been accelerating over the last three decades, from just over 1/10 of one degree Fahrenheit per decade to almost 1/3 of a degree now.

By 2100, temperatures in the Northeastern U.S. are predicted to have risen by eight to twelve degrees, with the number of snow days at half of what we are used to now. A recent study by the Union of Concerned Scientists on the effects of global warming in the Northeast concluded that, under some scenarios, “Only western Maine is projected to retain a reliable ski season by the end of the century and only northern New Hampshire would support a snowmobiling season longer than two months.”

And it seems that as one moves farther north, more and more winter is lost. The Arctic Climate Impact Assessment of 2004 reported that Arctic temperatures are now rising at nearly twice the rate of the rest of the world (as much as 14 ˚ F over the next one hundred years), reducing sea ice and melting frozen soils. It’s been widely reported that Alaska’s polar bears are probably doomed by 2050, but the scale of this climatic shift will likely do much more—completely changing the culture of the Arctic.

Global warming impacts are far from monolithic: Some parts of the planet are heating up and others are experiencing colder than average temperatures and record snowfalls, just as climate models predicted. But the overall trend is clear: It’s getting warmer, and winter is losing intensity and duration. “If you’ve ever enjoyed ice skating, sledding, skiing, snowboarding, or building a snowman,” writes E/The Environmental Magazine, “you should know that the future of these enshrined institutions is by no means guaranteed.”