Last year was the hottest on record for the contiguous 48 states and the second-worst in terms of extreme weather events like tornadoes, wildfires and drought, part of a trend that scientists see strengthening with climate change, according to researchers at the National Oceanic and Atmospheric Administration.
In its annual report, “State of the Climate,” NOAA reported that the average annual temperature was 55.3 degrees Fahrenheit, 3.3 degrees greater than the average temperature for the 20th century. It was also a full degree higher than the previous record high average temperature set in 1998, the biggest jump from one record temperature to another.
The report also confirmed what Americans have lived through for the last year: extreme weather events that are becoming more common. The only year there were more extreme weather events was 1998, when a greater number of tropical cyclones made landfall. In 2012, the Upper Midwest was hit with floods, the mid-Atlantic with a sudden summertime storm called a derecho, the West with wildfire and the Northeast with Hurricane Sandy, among many other events. Most of the country remains in the grip of drought.
For years, climatologists have been reluctant to draw a line from climate change to specific weather events, and NOAA researchers on a conference call about the report were somewhat cautious about making links. But a growing body of research has started to indicate that climate change creates conditions for the kinds of temperatures and events the United States experienced last year, and scientist don’t expect such patterns to change considerably.
“We expect to see a continued trend of big heat events, we expect to see big rain events and with slightly less confidence, we expect to see continued trend in drought,” said Deke Arndt, chief of the climate monitoring branch, NOAA’s National Climatic Data Center. “This is consistent with what we would expect in a warming world.”