His actions have earned him both praise and criticism from the media and scientific community. Recent scientific endeavors of his — including a study last month that was publicized prior to being peer-reviewed — have also generated controversy.
In an interview with Yale Environment 360 last week, Hansen, former director of the NASA Goddard Institute for Space Studies in New York, opened up about his unconventional career path, his frustration watching policymakers’ four decades of climate inaction, and what he believes the world could look like a century from now.
“I don’t think that I have been alarmist — maybe alarming, but I don’t think I’m an alarmist,” he said. “We have a society in which most people have become unable to understand or appreciate science, and partly that’s a communication problem, which we need to try to alleviate.”
By my definition at least. Because he always, but always, comes up with alarmist and extreme answers. I think particularly of a paper of his about the right price for a carbon tax. He managed to grasp most of the economics of the point. Such a Pigou Tax should be at the expected level of the damage that would be done by emissions. Fair enough and correct.
He then looked at probabilities of various emissions paths. Maybe he got that right and maybe he didn’t, I’m not competent to judge. And his top estimate was for $1,000 per tonne CO2-e. Which might even be a useful number.
Then he got his basic statistics wrong. Because then he said that the carbon tax should be $1,000 per tonne CO2-e. Which is incorrect. You have to weight your various calculations by their probability. Because the likely outcome is of course determined by those probabilities you’ve earlier assigned. And when you do that his answer comes down to somewhere in the Stern-Nordhaus range of $80 to $250 (those two not being directly comparable with each other).
Hansen, alarmist? Yup.