Dyson: Thinking Man's Skeptic

Nicholas Dawidoff has written a long profile of Freeman Dyson in the New York Times magazine. The profile takes a broad look at his life but focuses on his skepticism about the threat of global warming. So far as I can tell, he doesn't doubt the greenhouse effect, or the fact of global warming, but mostly doubts that it is worth much trouble to prevent global warming. In particular, he thinks that James Hansen and colleagues pay too much attention to their models, and mistake them for reality.

It’s a nice piece, even if it tells the famous Feynman/Dyson bordello sink story in the lamest fashion possible.

Dyson made his reputation sixty years ago with his work on the foundations of quantum electrodynamics, showing, among other things, that the rather different appearing approaches of Feynman, Schwinger, and Tomonaga were equivalent. At that point, he already had a slot at the institute for advanced study, and he didn't even bother with the formalities of collecting his PhD.

He also retreated from fundamental physics, perhaps from a congenital tendency to dabble or maybe because he realized that he could not compete with Feynman and Schwinger.

The occasion of current attention is mainly Dyson's role as the thinking man's AGW skeptic. He is neither idiot, fanatic, or a scoundrel. It would be nice if his type were more common.

Climate models, he says, take into account atmospheric motion and water levels but have no feeling for the chemistry and biology of sky, soil and trees. “The biologists have essentially been pushed aside,” he continues. “Al Gore’s just an opportunist. The person who is really responsible for this overestimate of global warming is Jim Hansen. He consistently exaggerates all the dangers.”

One can doubt the fairness of these remarks. Climate models don't include plants or soils or soils or the nuclear dynamics of our local star, but it makes sense to consider these things in models decoupled from the global climate models. That kind of analysis is what science does. There are a lot of biologists working at determining the effects of climate change on plants and soils. The feedback in the other direction should not be neglected, but it is very likely to be a very slow process.

Hansen is the John the Baptist or maybe the Cassandra of global warming. John the Baptist doesn't say "The Messiah might be coming." Cassandra doesn't say "umm, maybe we should think about this Greeks bearing gifts thingy." And Hansen doesn't have much patience for Dyson's version of "maybe that horse might look good in the park."

More interestingtly, Dyson thinks that there are a number of things we can do to suck CO2 out of the atmosphere. His principal suggestions in this regard are to make more topsoil and to plant a whole lot of trees. These are not crazy ideas, since trees are mostly carbon and water and topsoil too packs a lot of carbon.

If more skeptics were like Dyson, I would probably be one of them.

Dyson is a big believer in technological possibility - he has imagined, for example, a rocket propelled by nuclear explosions and civilizations that capture the entire energy output of a galaxy. He thinks that if too much CO2 turns out to be a problem, that it shouldn't be too hard to fix.

Eventually Dyson published a paper titled “Can We Control the Carbon Dioxide in the Atmosphere?” His answer was yes, and he added that any emergency could be temporarily thwarted with a “carbon bank” of “fast-growing trees.” He calculated how many trees it would take to remove all carbon from the atmosphere. The number, he says, was a trillion, which was “in principle quite feasible.” Dyson says the paper is “what I’d like people to judge me by. I still think everything it says is true.”
Eventually he would embrace another idea: the notorious carbon-eating trees, which would be genetically engineered to absorb more carbon than normal trees. Of them, he admits: “I suppose it sounds like science fiction. Genetic engineering is politically unpopular in the moment.”

The core of Dyson’s objection is to the cure people like Hansen, Gore and most others want to impose.

For Hansen, the dark agent of the looming environmental apocalypse is carbon dioxide contained in coal smoke. Coal, he has written, “is the single greatest threat to civilization and all life on our planet.” Hansen has referred to railroad cars transporting coal as “death trains.” Dyson, on the other hand, told me in conversations and e-mail messages that “Jim Hansen’s crusade against coal overstates the harm carbon dioxide can do.” Dyson well remembers the lethal black London coal fog of his youth when, after a day of visiting the city, he would return to his hometown of Winchester with his white shirt collar turned black. Coal, Dyson says, contains “real pollutants” like soot, sulphur and nitrogen oxides, “really nasty stuff that makes people sick and looks ugly.” These are “rightly considered a moral evil,” he says, but they “can be reduced to low levels by scrubbers at an affordable cost.” He says Hansen “exploits” the toxic elements of burning coal as a way of condemning the carbon dioxide it releases, “which cannot be reduced at an affordable cost, but does not do any substantial harm.”…

[Dyson] has great affection for coal and for one big reason: It is so inexpensive that most of the world can afford it. “There’s a lot of truth to the statement Greens are people who never had to worry about their grocery bills,” he says. (“Many of these people are my friends,” he will also tell you.) To Dyson, “the move of the populations of China and India from poverty to middle-class prosperity should be the great historic achievement of the century. Without coal it cannot happen.” That said, Dyson sees coal as the interim kindling of progress. In “roughly 50 years,” he predicts, solar energy will become cheap and abundant, and “there are many good reasons for preferring it to coal.”

Dyson is a famous numbers man, so it’s a bit scary to try to argue numbers with him. He is convinced that trying to move quickly beyond coal would be too costly, but do his numbers for his own ideas make sense?

Eventually Dyson published a paper titled “Can We Control the Carbon Dioxide in the Atmosphere?” His answer was yes, and he added that any emergency could be temporarily thwarted with a “carbon bank” of “fast-growing trees.” He calculated how many trees it would take to remove all carbon from the atmosphere. The number, he says, was a trillion, which was “in principle quite feasible.” Dyson says the paper is “what I’d like people to judge me by. I still think everything it says is true.”
Eventually he would embrace another idea: the notorious carbon-eating trees, which would be genetically engineered to absorb more carbon than normal trees. Of them, he admits: “I suppose it sounds like science fiction. Genetic engineering is politically unpopular in the moment.”

So can an idea like this make sense? Trees are mostly carbon and water, so that part makes sense. For a trillion trees to do the job, they would have to be fairly big ones –several tons apiece. A ninety foot tall Douglas Fir is only about half a ton. A trillion trees is also a lot – nearly three times as many as the world currently has. Where do you put them? Using agricultural land would be catastrophic for world food supplies. If elsewhere, where do you get the fertilizer and water? There is a limit to the World’s primary biological production, and turning a few teratons of CO2 into tree and soil would suck up an awful lot of it.

In one respect Dyson probably has more in common with Hansen and the anti-global warming crusaders than with his conservative fellow skeptics:

Humans, he says, have a duty to restructure nature for their survival.

I strongly recommend Nicolas Dawidoff’s profile of Dyson.