The Moral Calculus of Climate Change

by Will Wilkinson on May 16, 2007

The RealClimate guys report on a conference on the ethics of climate change. Here’s their summary of Henry Shue’s presentation:

Henry Shue, a Oxford philosopher well known for his work on such issues as the moral implications of torture and pre-emptive war, made the argument that the moral implications of not dealing with climate change should be thought of not only in terms of harm, but in terms of potential harm. Unfortunately for those of us that would like to keep burning fossil fuels at our current rate, Shue argues that uncertainty — the possibility that harm caused to future generations from anthropogenic climate change will be relatively small — does not get us out of our moral obligation to change our behavior. That is, one need only recognize that business as usual will increase the risk of significant harm – a point that almost nobody debates – for it to be clear that business as usual may be unethical.

Maybe this isn’t what Shue actually said, and surely he said rather more, but I find this pretty uncompelling as stated.

First, the idea of obligations to distantly future generations strikes me as incoherent. These are people that do not actually exist, and the people who do eventually exist is a function of what we do and don’t do now, which is surely a serious complication. Even if we can imagine determinate future persons to whom we might have duties, it remains that we stand outside the Humean circumstances of justice with them, and so don’t in fact have duties with respect to them. I can make sense of an ”intergenerational chain” conception of obligations to future generations: I have obligations to my children and grandchildren; my children and grandchildren have obligations to their children and grandchildren; etc. I think this can get us a few general principles, like “leave enough and as good for the kids,” but it’s unclear how this can undergird any kind of significant sacrifice for indeterminate far-distant beneficiaries.

Second, even if we can find some ground for obligations to far-future generations, we’d need to be established that “business as usual” will in fact be a net harm to future generations. Suppose a small reduction in future warming requires a small reduction in economic growth every year from now to then. The longer the time frame, the greater the harm to future generations from reduced growth rates. At some point, the loss in standard of living will completely swamp the gains from reduced warming. And, of course, the longer the time frame for significant warming, the less likely it will be that dislocations from warming will be serious. Gradual changes in patterns of capital investment, migration, etc. will move many people out of harm’s way, and perhaps move many other into areas that will benefit from warming. And, of course, the more rapid the rate of economic growth, the more likely it is that effective technologies that will retard warming, or mitigate its effects, will come on the scene. The allegedly obligatory deviation from “business as usual” may be in the direction of doing more to accelerate economic growth. It is by no means obvious that this isn’t the best course. 

Looking at the RealClimate summaries, it seems to me that there is a bit of a bias toward emphasizing the potential harms of warming while de-emphasizing — or even arguing down — anything that might prevent or mitigate those harms. RealClimate’s Steig and Schmidt write:

one of the commentators at the conference made the argument that it was an open question whether we had any moral obligation towards future generations for our impact on the climate, since that impact could in principle be averted (for example through carbon dioxide removal via ocean iron fertilization). This is equivalent to saying that we will not have to address the issue of climate change if we address it, an argument that has no bearing whatsoever on whether we have a moral obligation. We were a bit surprised to hear it from a philosopher since it is a tautology (usually anathema to philosophers).

Sounds like the unnamed philosopher may have been saying something close to part of what I was saying above, and it doesn’t sound like a tautology to me. It sounds to me like he was saying that if we’re thinking about the probability of harm, then we also have to take into account the probability of the emergence of technologies that would prevent that harm because, otherwise, you can’t calculate the total probability of harm. Why try to avoid the obvious force of that point? Steig and Schmidt’s reply amounts to this, as far as I can tell: If the emergence of this technology is motivated by the recognition of a moral obligation to address the issue, then it weirdly self-defeating to argue that people therefore don’t have a moral obligation to address the issue. Sure, but I truly doubt that was the argument. It is confused to talk about whether “we” do or don’t address warming. Not everyone invents or even funds new technologies. If someone or other does this in the future, whatever their motivation, and that makes the problem go away, then the problem will have gone away. If the probability of this is high enough, and we know it, then the rest of us non-inventing, non-invention-financing folk, are obviously off the hook right now. Now, I don’t know the probabilities of any of these things. And neither does Steig and Schmidt or Henry Shue.

  • mk
    So if I read you right, you're basically saying four things:

    1) When we plot out the future effects of "business as usual", we'd better take into account technological change.

    That sounds uncontroversial.

    2) Predicting technological change is hard to do.

    Also uncontroversial.

    3) We owe nothing to future generations because they don't exist and might not even exist.

    I completely disagree. If they will likely exist then we must owe them something. As a totally crass intuitive approximation, if they are 50% likely to exist then we would appear to "owe them" with something 50% the weight of a current person. (This interestingly touches on abortion issues, but that's a digression.) Of course there are other factors, it's complicated. But I completely disagree with you here.

    4) Even if we did owe something to future generations, we should take into account pluses and minuses.

    This is also totally uncontroversial. Though the idea specifically applied to economic growth becomes a little more controversial. Still, I will grant you that for any future "negatives" due to environmental damage, there exists some (possibly astronomically high) appropriate level of economic growth that would provide just "compensation", or compensation plus a surplus.





    I think we do not run into problems here as long as

    1) We are clear with ourselves about what we mean by "business as usual" (for example, we're currently pumping some money into energy R&D every year... does business as usual mean that we don't jack up the rates of expenditure? Does it refer SPECIFICALLY to the U.S., thus permitting us to be free-riders on R&D advances made by European companies, if they choose to jack up their expenditures?)

    2) We are honest with ourselves about the uncertainty in our predictions. I don't think uncertainty per se means it's useless to try to forecast-- though if there's enough uncertainty it may become useless.
  • You've argued before that we can't owe duties to people who don't exist yet. I don't see why not. Legally, it is possible to owe duties in respect of a transaction to people who exist when the transaction is completed, even if they didn't exist when it started. I'd think some of these legal duties would be moral duties as well. If I negligently or deliberately exposed a woman to a chemical which would disable her offspring, it is irrelevant to my culpability that they are not yet born or even conceived.
  • Tom
    Hi Will,

    You seem to present three reasons why we dont have moral obligations to future generations. The first two are that
    1. funture generations are comprised of people who do not exist.
    2. which future people exist depends on what we do now.

    You say that these two facts lead to a 'serious complication' for arguments for the claim that we have these obligations. This is true, but there is an extensive literature on the subject (Parfit, James Woodward, Simon Shriffin) addressing these complications, which at leasts suggests that the idea of obligations to future generations are not incoherent.

    The third reason you present is that
    3. We don't stand in the Humean circumstances of justice towards future generations.

    But even if we accept that Humean theory, it only follows that we dont have obligations of justice towards future generations. We might have other moral obligations.

    Also, I'm not sure we have to establish that the choices which lead to warming are a net harm for the future generations considered together. Does this claim derives from a summative utilitarian view? Alternatively, we might think that there are basic rights which should not be violated even if there is a net gain to others from voilating those rights.

    I agree about the bias in these debates: but also, those who are more sceptical about duties seem to be more sceptical about the science and optimistic about technofixes. The biases are on both sides.
  • Javier
    the idea of obligations to distantly future generations strikes me as incoherent. These are people that do not actually exist, and the people who do eventually exist is a function of what we do and don’t do now, which is surely a serious complication.

    I don't see anything incoherent about such duties. It just means that you likely can't ground them in a person-affecting moral theory. If you, on other hand, think there are some impersonal values or principles, then there are such duties. This is of course standard fare since Reasons and Persons. But it seems that you are antecedently committed to skepticism about impersonal values. That needs to be justified. It seems, at any rate, that commonsense morality endorses some impersonal values, such as desert, among others.
  • dilys
    I know when operating in the realm of individual human behavior, and so probably in collective issues that affect each individual (as "Defeat AGW" policies will), we are obligated in all serious matters to ask ourselves, When do we need to know? As well as, How much do we need to know? -- at each point along the continuum, to evaluate and exploit predictable resiliency and alternative models. Taking into consideration formulae of certainty, risk of harm, and causality, that are far past my pay grade.

    Any sign of willingness to lay out these metrics and fight over them one by one?

    I submit the approach is distinguishable both from stonewalling, and from the conclusory Chicken Little Al Gore Rhythm(TM).
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