United States Global Change Research Program
Last week the National Oceanic and Atmospheric Administration (NOAA) released temperature data showing that, in the contiguous United States, March 2012 was warmer than any other March on record. In fact, last month broke 15,272 high-temperature records and averaged fully 8.6º F warmer than the 20th-century average for March in the United States. The data also show that the year’s full first quarter—January, February, and March—was also the warmest ever recorded.
This year’s oddball winter has left many Americans wondering to what extent the anomalous heat, premature blooms, and early onslaught of allergy-provoking pollen across much of the United States can be attributed to human-caused climate change.
No individual weather pattern—not even one lasting three-months—can be definitively attributed to human-induced climate change, or any other single cause. But scientists have known for some time that the likelihood of unusually warm seasons is increasing as a result of emissions of heat-trapping gases generated by human activities.
According to a study published in the journal Climatic Change Letters, high summer-season temperatures that used to occur in the United States only 5% of the time (i.e. one year in 20) are now occurring at least 30% of the time throughout the lower 48 states.
Sooner or later, this science is going to sink in. I hope it’s sooner.
{ 6 comments… read them below or add one }
Kim 04.19.12 at 4:52 pm
And the UK looks set to get its coldest May in a century! Freaky weather for sure.
doug (dh) 04.19.12 at 8:13 pm
and there is major snow and new ice formin at the poles lately. Record cold in the Arctic and Antarctic circles.
Anonymous 04.20.12 at 4:58 am
It’s going to weather whether we want it to or not. So… short pants and t-shirts or down jackets, you just have to deal with it.
Richard 04.20.12 at 6:14 am
Anonymous - if you don’t mind me saying so, that’s a nonsensical comment.
Doug - Welcome back! Do you have a source for that claim?
Tony Buglass 04.20.12 at 2:31 pm
Good to hear from you again, Doug - it’s been a while. There was something on a weather blog (BBC, I think) showing that Arctic ice had pretty much grown back to where it should be after a marked reduction last year. The cause of the Siberian winter spell the UK and Europe had earlier this year was an ice-free patch of the Arctic ocean; the temperature gradient between open sea and Arctic air was much greater than that between ice and air, so caused the growth an anticyclone where one wouldn’t normally occur. The result was that the airflow around it funnelled Arctic air at us, which would normally have gone elsewhere. My Estonian friends said they got -37 deg C, when their winter normal is more like -25 or so. In the first place, that illustrates how warmer climate reducing Arctic ice could in fact cause much colder weather in Europe. In the second place, it’s interesting to note how the ice grew back during the latter part of the winter. It remains to be seen how far it melts back in the coming year.
Richard 04.20.12 at 2:42 pm
Thanks for that Tony. In any case, one season’s events aren’t really the issue. That’s “weather”. The science of climate change is concerned with long term trends. And they are becoming increasingly clear.