Tuesday, March 18, 2014

Acts Vs Words: The Case of Nordhaus

In the piece I discussed in my previous post, responding to a WSJ article critical of the current global warming orthodoxy, William Nordhaus attacks the idea that climate scientists are under pressure not to take positions skeptical of global warming. He begins by making fun of the comparison to the enforcement of orthodoxy under Stalin. While it is true that the piece he is criticizing made that comparison, its actual argument was that dissenting scientists "are afraid to speak up for fear of not being promoted—or worse… ." Pointing out that  "No skeptics have been arrested or banished to gulags or the modern equivalents of Siberia" does not answer that. 

Nor does observing that "the dissenting authors are at the world’s greatest universities." As Nordhaus is surely aware, firing tenured professors is difficult. Failing to hire or to promote is much easier. Furthermore, his list of universities at which the scientists who signed the WSJ piece are employed ignores the fact that most of them are not in climate science, making it irrelevant to the argument he is offering—a fact Nordhaus surely knows, but most readers of his piece probably do not.

His conclusion: "I believe the opposite of what the sixteen claim to be true: dissident voices and new theories are encouraged because they are critical to sharpening our analysis."

His argument in support of that claim I find unpersuasive, but that does not imply that the claim itself is false. The piece he is criticizing, after all, offered no evidence in favor of its claim in the opposite direction. Nordhaus himself, however, provides some—not in words but in deeds.

The claim of the critics is summed up in the title of their article: "No Need to Panic About Global Warming: There's no compelling scientific argument for drastic action to 'decarbonize' the world's economy." The claim of those on the other side is the opposite—that global warming poses a severe threat to human welfare and drastic action is needed to slow it. Which side of that argument does Nordhaus' own research, as reported in his article, support?

The answer is clear. He finds that the net cost of waiting fifty years instead of taking the optimal actions now is $4.1 trillion dollars. Spread out over the rest of the century, that comes to about $48 billion/year, or about .06% of current world GNP. Which position is that closer to, that there is a need to panic and take drastic action or that there is not?

And yet, when Nordhaus publishes an article in the New York Review of Books, a very high profile publication, it is an attack on the critics, not an attack on those who, according to his own research, vastly exaggerate the scale of the problem and the need for immediate, drastic action.

A central idea of economics is revealed preference—we judge people by what they do, not by what they say.


TJIC said...

I love how understated you are. Your piece is, in my opinion, an utterly devastating response, culminating in the last line...and all with nary a whisper of hostility of ego.

Well done..

Anonymous said...

Very acute analysis.

Bob Murphy said...

Although I support very much David's recent investigations of climate science and policy responses, I quibble with this particular post at my blog:


David, I replied to you in the comments; I don't see where you're getting the year 2100 as an end point.

David Friedman said...

Bob: You may be correct--I've responded on your blog. I've also emailed Nordhaus to see if I can get an answer as to what period he is summing costs and benefits over.

If it's over 250 years, as some things in his manuscript seem to suggest, that makes his numbers very close to worthless. As he himself concedes:

"At the same time, we must emphasize that, based on our
formal analysis of uncertainty, we have relatively little confidence in our projections beyond 2050."