Eric Steig & Ray Pierrehumbert

One of my (Eric’s) favorite old books is The Starship and the Canoe by Kenneth Brower It’s a 1970s book about a father (Freeman Dyson, theoretical physicist living in Princeton) and son (George Dyson, hippy kayaker living 90 ft up in a fir tree in British Columbia) that couldn’t be more different, yet are strikingly similar in their originality and brilliance. I started out my career heading into astrophysics, and I’m also an avid sea kayaker and I grew up with the B.C. rainforest out my back door. So I think I have a sense of what drives these guys. Yet I’ve never understood how Freeman Dyson became such a climate contrarian and advocate for off-the-wall biogeoengineering solutions like carbon-eating trees, something we’ve written about before.

It turns out that Brower has wondered the same thing, and in a recent article in The Atlantic, he speculates on the answer. “How could someone as smart as Freeman Dyson,” writes Brower, “be so wrong about climate change and other environmental concerns..?”



Brower goes through a number of possible explanations for the Dyson paradox, some easily dismissed (senility; he’s a theoretician with no sense of practicality) some not so easily dismissed (he’s only joking, don’t take it seriously, he doesn’t take it all that seriously himself). But in the end, for Brower, it seems to come down to two conspiring things about Dyson. The first is that Dyson has an abiding faith in the ability of technology to do anything we want it to. It’s not surprising, then, that Dyson thinks we can ‘fix climate’ as well. That, in itself, makes Dyson not so much a “global warming skeptic” as an extreme techno-optimist. In fact, even leaving technology aside, he has a touching faith that whatever humans may do to the environment, it usually turns out for the best. In this essay, he writes:

“The natural ecology of England was uninterrupted and rather boring forest. Humans replaced the forest with an artificial landscape of grassland and moorland, fields and farms, with a much richer variety of plant and animal species. Quite recently, only about a thousand years ago, we introduced rabbits, a non-native species which had a profound effect on the ecology. Rabbits opened glades in the forest where flowering plants now flourish.”

We daresay that the Australians have a somewhat less benign view of rabbits (as the New Zealanders do of possums). And that maybe Dyson has a thing or two to learn about the biodiversity of unmanaged ecosystems.

Second, Dyson’s obsession has always been the stars, not the earth: he spent many years working on the design of a spaceship (hence the title of Brower’s 30-year old book) that would take him there. It’s not so much that he doesn’t care about our home planet — he must have learned something about ‘spaceship earth’ from son George over the years. Rather, he is simply very confident that we can always get off if we have to. “What the secular faith of Dysonism offers,” Brower writes” is, first, a hypertrophied version of the technological fix, and second, the fantasy that, should the fix fail, we have someplace else to go.” Dyson has stated in many places, and in various ways, that he thinks global warming is not a big problem, and that its importance has been exaggerated. To put things in perspective, though, Dyson doesn’t particularly think that the extirpation of all life other than human would be a particularly big deal “We are moving rapidly into the post-Darwinian era, when species other than our own will no longer exist, and the rules of Open Source sharing will be extended from the exchange of software to the exchange of genes,” he is quoted as saying in Brower’s article. Dyson’s idea of what constitutes a “big problem” may be, well, just a bit different from what most of the rest of us might have in mind.

Brower’s conclusions sound right on the mark to us, but don’t fully explain Dyson. Perhaps Brower is being gentle, since he is an old friend, or perhaps he simply isn’t aware of it, but one issue he does not touch on in his article is is how deceptive (apparently deliberately) Dyson can be.

The problem is that Dyson says demonstrably wrong things about global warming, and doesn’t seem to care so long as they support his notion of human destiny. Brower reports that Dyson doesn’t consider himself an expert on climate change, has no interest in arguing the details with experts, and yet somehow knows that the experts don’t have any answers worth listening to. That doesn’t stop Dyson from making sweeping pronouncements, many of them so egregiously wrong that it would hardly have taken an expert to set him straight.

The examples of this are legion. In the essay “Heretical thoughts about science and society” (excerpted here) Dyson says that CO 2 only acts to make cold places (like the arctic) warmer and doesn’t make hot places hotter, because only cold places are dry enough for CO 2 to compete with water vapor opacity. But in jumping to this conclusion, he has neglected to take into account that even in the hot tropics, the air aloft is cold and dry, so CO 2 nonetheless exerts a potent warming effect there. Dyson has fallen into the same saturation fallacy that bedeviled Ångström a century earlier.

And then there are those carbon-eating trees. He likes this one so much he put it in both the Heresy essay and in his piece in NY Review of Books. He points out that the annual fossil fuel emissions of carbon correspond to a hundredth of an inch of extra biomass per year over half the Earth’s surface, and suggests that it shouldn’t be hard to tweak the biosphere in such a way as to sequester all the fossil fuel carbon we want to in this way. Dyson could well ask himself why we don’t have kilometers-thick layers of organic carbon right now at the surface, resulting from a few billion years of outgassing of volcanic CO 2 . The answer is that bacteria have had about two billion years to evolve so as to get very, very good at combining any available organic carbon with oxygen. It is in fact extremely hard to put organic carbon in a form or place where it doesn’t get oxidized back into CO 2 (Mother Nature thought she had done that trick with fossil fuels but we sure fooled her!) And if you did somehow coopt ten to twenty percent of the worldwide biosphere’s photosynthetic capacity to take up carbon and turn it into a form that couldn’t rot ever, you’d have to sort of worry about how nutrients would ever get back into the ecosystem. And also maybe whether the carbon-eating trees might get out of control and suck out so much CO 2 you wound up in a Snowball Earth.

Dyson espouses a generic disdain for climate models and climate modellers: ” Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models.” Like most of us, he has little confidence in the modelling of clouds. But with great ignorance of the nature of the modelling enterprise, he declares: “It is much easier for a scientist to sit in an air-conditioned building and run computer models, than to put on winter clothes and measure what is really happening outside in the swamps and the clouds” Actually, those of us who go to Antarctica to drill ice cores certainly put on winter clothes, and paleoclimatologists are out in the swamps and ocean muck all the time. And there are plenty of scientists flying around in the clouds, trying to gauge their effects. The mainstream estimate that the climate sensitivity is around 3°C for a doubling of CO 2 does not simply comes from computer models. Study of the Last Glacial Maximum, the Pliocene and the Paleocene-Eocene Thermal Maximum all rule out the idea that there is a strongly stabilizing cloud feedback. Ahe fact that we cannot precisely quantify cloud feedbacks also means that there is a lot of risk, that cloud feedbacks could make a doubled-CO 2 world much hotter, not much cooler. Dyson’s writings conveniently ignore this two-directional implication of uncertainty, and they they also ignore the implications of the long atmospheric lifetime of CO 2 , which means if we wait and see how hot it gets and find we don’t like it, there’s nothing much to be done (unless, of course, we can simply go somewhere else).

Finally, there is the familiar examples of Dyson attacking the style of the debate, rather than its substance. Reporting on written debate between Richard Lindzen and Stefan Rahmstorf, in the New York Review of Books New York Times book review , Dyson juxtaposes Lindzen’s claim that “observations suggest that the sensitivity of the real climate is much less than that found in computer models” with Stefan calling this “simply ludicrous”. Dyson gives the impression that rational arguments from skeptics are met with “open contempt” by the majority. But he fails to mention that Stefan showed in detail why Lindzen’s claim is wrong: Lindzen ignored ocean thermal inertia when comparing observed warming with the equilibrium climate sensitivity. Any physicist should be able to judge that Stefan is right and Lindzen is wrong on this point. He also failed to mention that Stefan used the word “ludicrous” only in a “personal postscript” to a completely sober scientific article, referring to Lindzen’s claims that a vast conspiracy of thousands of climatologists worldwide is misleading the public for personal gain. Dyson’s account of the Lindzen-Rahmstorf exchange neither fairly covers the substance of the argument, nor is it a fair portrayal of its style – Dyson seems to have twisted it as much as he could to score a political point.

In the Heresy essay, Dyson repeatedly gives himself a way out by claiming he is only tossing out ideas that should be thought about; he at times emphasizes that he does not know the answers, only the questions that should be raised. However, that does not stop him from making confident claims that he has a broader view than others, as in this interview with Mike Lemonick, and somehow Dyson never gets around to thinking about what the consequences are if we continue inaction on CO 2 emissions and he turns out to be wrong. More importantly, all of the things Dyson argues “heretically” should be looked at — e.g. land carbon sequestration or the lessons from the Altithermal period around 8000 years ago — are in fact already being intensively investigated and are not turning up any silver bullets to allay concern about climate change. When push comes to shove, Dyson is really only offering warmed-over standard contrarian talking points. Heresy, or more broadly an outsider’s viewpoint, can be a good thing when it shakes loose new ideas. But surely, we have a right to expect a more original form of heresy from the architect of Dyson spheres and nuclear starships.

In short, it’s not so simple as the ‘self delusion’ Brower talks about. Dyson is not doing science, but he is deluding others under the guise of science. Given’s Dyson’s evident love of science (and expertise in it), that’s the part that we still don’t get.