Human-driven climate change is to blame for a series of increasingly hot summers and the situation is already worse than was expected just two decades ago, a top NASA scientist said on Saturday.
James Hansen, who directs the NASA Goddard Institute for Space Studies, wrote in the Washington Post that even his “grim” predictions of a warming future, delivered before the US Senate in 1988, were too weak.
“I have a confession to make: I was too optimistic,” Hansen wrote.
“My projections about increasing global temperature have been proved true. But I failed to fully explore how quickly that average rise would drive an increase in extreme weather.”
Hansen and his colleagues have published in the Proceedings of the National Academy of Sciences an analysis of the past six decades of global temperatures, revealing a “stunning increase in the frequency of extremely hot summers,” he wrote.