DID GLOBAL warming contribute to the punishing heat wave much of the country endured during the summer of 2012? How about Superstorm Sandy? A group of 78 scientists led by experts from the National Oceanic and Atmospheric Administration (NOAA) last week gave their preliminary answers, releasing a series of peer-reviewed analyses on those and other major weather events from last year. The picture they offer is of a planet in which warming has boosted the chances, in some cases significantly, that certain unwelcome weather or weather-related disasters will occur.
Not every instance of bad weather is related to global warming. Of the 12 extreme weather events scientists studied, experts saw evidence of a climate-change component in only half.
One of them, though, was that 2012 heat wave: Global warming probably factored into the magnitude of the highs. One of the papers reckons that climate change was responsible for about 35 percent of last year’s heat. “High temperatures, such as those experienced in the U.S. in 2012, are now likely to occur four times as frequently due to human-induced climate change,” NOAA notes, citing findings from a different paper in its report on the same event. Another phenomenon last year, very low Arctic sea ice, “cannot be explained by natural variability alone.”