A fascinating article today by Seth Bornstein of the Associated Press documents how global warming is effecting the United States differentially, with the greatest change since 1984 taking place in the Northeast and Southwest. You can read the whole article here. Highlights from this article follow:
“Northeastern states — led by Maine and Vermont — have gotten the hottest in the last 30 years in annual temperature, gaining 2.5 degrees on average. But Southwestern states have heated up the most in the hottest months: The average New Mexico summer is 3.4 degrees warmer now than in 1984; in Texas, the dog days are 2.8 degrees hotter. The contiguous United States’ annual average temperature has warmed by 1.2 degrees since 1984, with summers getting 1.6 degrees hotter. But that doesn’t really tell you how hot it’s gotten for most Americans. While man-made greenhouse gases warm the world as a whole, weather is supremely local. Some areas have gotten hotter than others because of atmospheric factors and randomness, climate scientists say. “In the United States, it isn’t warming equally,” said Kelly Redmond, climatologist at the Western Regional Climate Center in Reno, Nevada. “Be careful about extrapolating from your own backyard to the globe.”
“To determine what parts of the country have warmed the most, The Associated Press analyzed National Climatic Data Center temperature trends in the lower 48 states, 192 cities and 344 smaller regions within the states. Climate scientists suggested 1984 as a starting date because 30 years is a commonly used time period and 1984, which had an average temperature, is not a cherry-picked year to skew a trend either way.
“All but one of the lower 48 states have warmed since 1984. North Dakota is the lone outlier, and cooled slightly. Ten states — Maine, Vermont, New Jersey, Massachusetts, New Hampshire, Rhode Island, Delaware, New Mexico, Connecticut and New York — have gotten at least 2 degrees warmer in the past 30 years.Since 1984, 92 percent of the more than 500 cities and smaller regions within states have warmed and nearly two-thirds of them have warmed by at least a degree. The regions that have warmed the most have been New York’s St. Lawrence Valley, northeastern Vermont, northern Maine, the northeastern plains of New Mexico and western Vermont, all of which have warmed by more than 2.5 degrees.
“The Southwest warming, especially in the summer, seems to be driven by dryness, because when there is little water the air and ground warm up faster, said Katharine Hayhoe, a climate scientist at Texas Tech University in Lubbock. And in the Northeast, the temperatures are pushed up by milder winters and warm water in the North Atlantic, said Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research. And less snow on the ground over the winter often means warmer temperatures, said Alan Betts, a climate scientist at Atmospheric Research in Pittsford, Vermont.”