美国2012年气候反常 三个月来连破高温纪录

It's been so warm in the United States this year, especially in March, that national records weren't just broken, they were deep-fried.

Temperatures in the lower 48 states were 8.6 degrees above normal for March and 6 degrees higher than average for the first three months of the year, according to calculations by the National Oceanic and Atmospheric Administration. That far exceeds the old records.

The magnitude of how unusual the year has been in the US has alarmed some meteorologists who have warned about global warming. One climate scientist said it's the weather equivalent of a baseball player on steroids, with old records obliterated.

"Everybody has this uneasy feeling. This is weird. This is not good," said Jerry Meehl, a climate scientist who specializes in extreme weather at the National Center for Atmospheric Research in Boulder, Colo. "It's a guilty pleasure. You're out enjoying this nice March weather, but you know it's not a good thing."

It's not just March.

"It's been ongoing for several months," said Jake Crouch, a climate scientist at NOAA's National Climatic Data Center in Ashville, N.C.

Meteorologists say an unusual confluence of several weather patterns, including La Nina, was the direct cause of the warm start to 2012. While individual events can't be blamed on global warming, Crouch said this is like the extremes that are supposed to get more frequent because of manmade climate change from the burning of fossil fuels such as coal and oil.

Normally, March averages 42.5 degrees across the country. This year, the average was 51.1, which is closer to the average for April. Only one other time — in January 2006 — was the country as a whole that much hotter than normal for an entire month.

In March, at least 7,775 weather stations across the nation broke daily high temperature records and another 7,517 broke records for night-time heat. Combined, that's more high temperature records broken in one month than ever before, Crouch said.

"When you look at what's happened in March this year, it's beyond unbelievable," said University of Victoria climate scientist Andrew Weaver.