Field of Science

Freeman Dyson on Climate Change

The New York Times has an article on eminent physicist Freeman Dyson's skepticism of climate change arguments. Several passages struck me in particular:
Dyson agrees with the prevailing view that there are rapidly rising carbon-dioxide levels in the atmosphere caused by human activity. To the planet, he suggests, the rising carbon may well be a MacGuffin, a striking yet ultimately benign occurrence in what Dyson says is still “a relatively cool period in the earth’s history.” The warming, he says, is not global but local, “making cold places warmer rather than making hot places hotter.” Far from expecting any drastic harmful consequences from these increased temperatures, he says the carbon may well be salubrious — a sign that “the climate is actually improving rather than getting worse,” because carbon acts as an ideal fertilizer promoting forest growth and crop yields. “Most of the evolution of life occurred on a planet substantially warmer than it is now,” he contends, “and substantially richer in carbon dioxide.” Dyson calls ocean acidification, which many scientists say is destroying the saltwater food chain, a genuine but probably exaggerated problem. Sea levels, he says, are rising steadily, but why this is and what dangers it might portend “cannot be predicted until we know much more about its causes.”
Beyond the specific points of factual dispute, Dyson has said that it all boils down to “a deeper disagreement about values” between those who think “nature knows best” and that “any gross human disruption of the natural environment is evil,” and “humanists,” like himself, who contend that protecting the existing biosphere is not as important as fighting more repugnant evils like war, poverty and unemployment.
His basic argument seems to be that, yes, human activity is causing global temperatures to rise, but this may not be a bad thing. Life, and humanity, will adjust to life in the new climate through adaptation and evolution, and may even emerge richer and stronger.

In a long-term sense, he is completely right. Life on earth has survived much greater shocks in the past and will likely continue to adapt and evolve as long as the sun is shining. We humans are a particularly adaptable bunch; we don't need to wait for genetic evolution to change our behaviors. We have devised ingenious solutions to our problems in the past, and we could probably think of something to carry us through whatever changes may come.

But the problem with this argument is the short-term. Humanity and life in general may be infinitely adaptable, but the fact is that, for the moment, we have adapted to life on the planet the way it is. We depend on certain plants and animals for food. These plants and animals in turn depend on other plants and animals, as well as certain chemicals and climate conditions. Every step in this chain is, for the moment, perfectly adapted to the climate of the present. Nature has even devised its own mechanisms to keep the current climate in place: for example, ocean bacteria help regulate the earth's temperature and atmosphere. We are, at present, in a state of equilibrium.

Massive increases in carbon dioxide, leading to rapid temerature growth, would push us out of equilibrium. Nature's homeostatic (equilibrium-maintaining) mechanisms would be insufficient to maintain our current climate, and large changes would occur. Food chains would have to be restructured as intermediate links go extinct. Some species would win and some would lose in the scramble to adjust to the new status quo.

Ecologists know that an ecosystem pushed out of equilibrium will eventually reach some new equilibrium state. But the details of this new state are impossible to predict ahead of time. Which species will dominate? What new food chains will form? This is the big question of climate change; no one can really say.

As far as we humans are concerned, the odds that this new state will be better for us are pretty low. Consider, for example, that the typical American diet is built from a relatively small variety of fruits, vegetables, grains, and animals. And the genetic variety within these crops is decreasing as breeds become standardized within the agriculture industry. It's unlikely that the specific plants and animals we depend on will be winners in the new equilibrium, since they, like us, are adapted to what we have now. We will have to scramble to change how we eat, as well as where we live, thanks to sea level changes. Millions of lives will be disrupted in this change. We have to ask ourselves, as a society, if we this disruption is an acceptable tradeoff to maintain our current energy habits a little longer.

As mathematician and ecologist Simon Levin said, “Nature is not fragile... what is fragile are the ecosystems services on which humans depend."


  1. Well, plenty to take issue with. Most obviously from the text you quoted is Dyson's failure to weigh the possible negative impacts climate change might have on the more repugnant evils [whatever that means] of war, poverty and unemployment.
    If he's really concerned about those things, he'd be leading the charge to free ourselves from dependence on fossil fuels, not because of the carbon emission whose impact we can not truly know (until it is too late), but because the war that will eventually be fought over what's left of the world's fossil fuels is going to put all past wars to shame--unless by the time those sources of energy run out we've weaned ourselves of our dependence on them.

    More generally, Dyson's not much of a humanist if he's for anything that risks the unknown, yet he inadvertently admits the he's all for blindly mixing the pot when he tries to criticize the nature knows best crowd by arguing that we're currently incapable of knowing specifically the outcome of our impact on the environment.

    Not so much in response to Dyson as in response to the public uptake of the topic of climate change, sustainability and conservation that Dyson is responding to, I tend to see all sides of the debate as suffering from the same false conceit, that there's some global human consciousness in play, and that the prize is getting to choose humanities course.

  2. Indeed, his attitude seems remarkably cavalier: We don't know what's going to happen but I assume it won't be too bad.

    In regards to your last point, yes, perhaps the message of environmentalists should be less "We know what will happen and it's going to be bad" and more "We don't know what's going to happen, and not knowing is VERY bad."

  3. I think he's mainly right: there are a lot of unknowns, there is a lot of exaggeration. I think it's fair to bring up the cost of doing what the Hansens and Gores want us to do, a cost he sees as keeping India and China -- so let's say about 1/3rd of the planet -- from joining the developed world.*
    I think his stance on climate change has to be looked at in the context of his signature issue(s): nuclear bombs, nuclear proliferation, war.

    I'd say he's a bit peeved that his issues aren't the sexy ones, and that's partially driving his negativism .. but still, he's mainly right.

    * I should disclose that I'm a big supporter of Gore; still am. Also to Edward's question: surely he has, his whole point on coal and the implied trade-offs therein.

  4. Well, clearly I disagree. There truly is a scientific consensus around the points that a) human activity is causing global temperatures to rise, and b) this will have negative consequences. The only disagreement is over what these consequences will be---hardly an excuse for inaction.

    As for the cost to the developing world, it's well-known that it would be simply impossible for all people on Earth to live the lifestyle Americans currently do, not just in terms of energy usage, but total resource consumption and waste production. So bringing the rest of the world in line with our lifestyle is not a goal that makes sense.

    I'm not saying India and China shouldn't develop economically, but they must do so in an environmentally sustainable way, just as we Americans must alter our current habits to make our own lifestyles sustainable.

  5. To the Chinese and Indians then: not only can you not be today's Americans (gluttonous hogs), you can't even be yesterday's Americans (sooty industrial-manufacturing wundermarvels).

    This stinks, and you should be thankful for your Dysons et al who are able to crawl out of their American-centric thinking box and contribute at a global level. Derailing a couple billion from achieving a level of the poorest Americans, if Dyson is right, well that is a cost. That's all he's saying. Make sure your actions result in benefits that exceed that cost.

    I agree with him in this. And that denuclearization is getting the short shrift in all of this (opportunity cost). (Somebody should tie together 'nuclear winter' and 'global warming')

  6. Well, you're right. Telling India and China to power their industrial and technology revolutions without relying on coal is asking them to make a sacrifice. And it's a sacrifice that we, as Americans, did not have to make. So yes, it's not fair.

    I'm arguing, as a pragmatic matter, that the "fair" solution of giving every country and region their turn to consume like turn-of-the-millenium Americans is simply impossible. I don't think the Earth's resources can support it. So I think we have to look for another solution.

  7. Maybe there's no fair solution then. In which case we look for the least unfair. I think this is the context in which the Dyson article should be (re-)read.


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