Extreme summer heat waves and droughts in recent years are the result of climate change, a top federal scientist concludes in a new peer-reviewed study.
The study by James Hansen, director of NASA’s Goddard Institute for Space Studies, could provide new political ammunition for environmentalists struggling to defend and advance climate regulations. Hansen touted the analysis he authored with two colleagues – which will be published Monday – in a weekend Washington Post column.
“These weather events are not simply an example of what climate change could bring. They are caused by climate change. The odds that natural variability created these extremes are minuscule, vanishingly small,” Hansen writes in summarizing the analysis of 60 years of global temperature data.
Hansen writes that the major European heat wave of 2003, the brutal Russian heat wave of 2010 and droughts in Texas and Oklahoma last year can be attributed to climate change, and that forthcoming data will likely reveal the same cause for this year’s record-breaking summer heat.
The study will be published in the Proceedings of the National Academy of Sciences, a peer-reviewed journal.
Hansen is an outspoken advocate who has been warning of the
dangers of climate change for decades. In 2011 he was arrested alongside
other activists outside the White House at a demonstration against the
proposed Keystone XL oil sands pipeline.
Hansen uses the Post
column to reiterate his call for a gradually escalating carbon fee
collected from fossil fuel companies, with the money rebated to
Americans on a per-capita basis.
As the Associated Press notes here, Hansen breaks with some other researchers in abandoning the caveat that while climate change is expected to bring more extremes, no specific weather can be laid at its feet.
Here’s a blurb from the Post:
This is not a climate model or a prediction but actual observations of weather events and temperatures that have happened. Our analysis shows that it is no longer enough to say that global warming will increase the likelihood of extreme weather and to repeat the caveat that no individual weather event can be directly linked to climate change. To the contrary, our analysis shows that, for the extreme hot weather of the recent past, there is virtually no explanation other than climate change.
According to a National Academy of Sciences summary of the Hansen’s new research, he looked at summer surface temperature anomalies during a “base period” between 1951 and 1980, and compared it to more recent years.
“Their findings revealed that extremely hot summers – those with temperatures three standard deviations greater than the mean temperature in the base period – occurred much more frequently in the past several years than during the base period, when they were practically absent,” the summary released over the weekend states.
“These extremely hot summers have affected an estimated 10% of global land area in recent years, compared with less than 1% of the Earth’s surface during the base period,” the summary states.