Leading scientist says he underestimated climate change


This is not the kind of headline that inspires confidence or optimism: “Climate change is here — and worse than we thought.”

The accompanying op-ed was written by James Hansen, a top scientist at NASA and a leading climate-change researcher. And in the second paragraph, he says his earlier projections for what climate change will look like were too optimistic.

“My projections about increasing global temperature have been proved true,” he writes. “But I failed to fully explore how quickly that average rise would drive an increase in extreme weather.”

Hansen wrote his op-ed in advance of a peer-reviewed study that’s coming out today; it’s published by the National Academy of Sciences. He and other researchers studied 60 years’ worth of temperature data, and regarding the extreme heat waves in recent years, there’s virtually no explanation other than climate change, he writes. He expects that data for this summer, once it’s all been collected, will show the same.

“The odds that natural variability created these extremes are minuscule, vanishingly small,” he writes.