Justice and the Assignment of the Intergenerational Costs of Climate Change

Matters of intergenerational justice are fundamental to discussions of justice and climate change. This is the case for several reasons. We are confident that our emissions of carbon dioxide (CO2) are having an effect on the global climate system. The Intergovernmental Panel on Climate Change's (IPCC) six different climate models in their Fourth Assessment Report (AR4) predict global mean temperature increases ranging from 1.8°C to 4.0°C during this century.1 This is projected to increase global mean sea levels by 0.18 to 0.59 meters.2 The attendant weather changes are less certain, as is how they will vary from region to region. But some of the effects that AR4 predicts as very likely include hotter high temperatures, more frequent heat waves, and greater precipitation in high latitudes. Effects that it estimates as likely include decreased precipitation in the subtropics and increased intensity of tropical cyclones.3 The Third Assessment Report (TAR) warns of a weakening of the thermohaline circulation and its possible abrupt shutdown after 2100.4 Unlike TAR, however, AR4 does not discuss the probabilities of severe or catastrophic adverse effects. But this absence is the subject of controversy among climate scientists, some of whom charge that politically motivated redactions to AR4 occurred.5 The effects of anthropogenic climate change will produce costs for persons in the future who will have to adapt to the changes. Crops will need to be changed or farmers will have to move. For many people food security will be threatened; some will go hungry as a result; other will starve. Homes and communities will need to be moved as sea levels rise. Some houses will be wiped out by sudden extreme storms. TAR stresses the disproportionate costs of adaptation for lower-income populations and the risks to populations in low-lying coastal regions and small islands. In general it predicts that, “[t]he impacts of climate change will fall disproportionately upon developing countries and the poor persons within all countries, and thereby exacerbate inequities in health status and access to adequate food, clean water, and other resources.”6 A recent study indicates that more than six hundred million people (ten percent of the world's population) live in low lying areas at higher risk to sea-level rises, and this amount is expected to increase as the urbanization of the global population continues.7 The effects of climate change and the costs of adapting to it can be mitigated by our policy choices. Such choices will produce mitigation costs for us as they will require significantly different energy production and use policies. Cleaner sources of energy are more expensive. The relative costs of the alternative sources of energy can be brought down by increasing the costs of using fossil fuels. But an increase in the absolute costs of energy is then guaranteed. It is highly unlikely that there will be significant mitigation without incurring such increased costs. The costs of adaptation and mitigation apply to a number of activities satisfying very important human interests, such as transportation, heating and cooling, shelter, food cultivation and production, security, income, government, and recreation. The assignment of the costs of mitigation and adaptation then is an important matter of justice. The matter of justice is between generations. It takes time to reduce global CO2 emissions. We have no experience of doing so yet. But even if we begin reducing, the IPCC projects that CO2 concentrations in the atmosphere will continue to increase in the absence of very large emissions reductions.8 TAR holds that “[s]tabilization of CO2 concentrations at any level requires the eventual reduction of global CO2 net emissions to a small fraction of the current level.”9 The level at which CO2 concentrations are stabilized will establish the assignment of costs, a higher level will involve fewer mitigation costs but higher adaption costs. In any case, even after stabilizing atmospheric concentrations of CO2, surface air temperature will continue to rise by a few tenths of a degree per century for a century or more, and sea levels will continue to rise for many centuries.10 The matters of intergenerational justice canvassed above are fundamental to an account of justice and climate change because in the absence of an account of duties to future generations any global regulatory scheme for sharing the mitigation costs of climate change intra-generationally, a scheme such as that which the international community must devise as a successor to the Kyoto Protocol, will be morally blind. It would be like agreeing on the relative proportions that members of a criminal ring must pay back their victims without setting an overall amount. There would be no assurance that the regulatory scheme was just unless it was directed toward fulfilling duties to future generations. Taking a position on this question of intergenerational justice, by, say, setting an atmospheric CO2 concentration target, is, however, unavoidable in the establishment of a post-Kyoto institutional framework. In this paper, I shall examine proposals for the distribution of the intergenerational costs of climate change. Settling on the appropriate principle is a complicated task for several reasons. The difficulties include, among others, how to deliberate impartially with respect to intergenerational principles and how to take account of the interaction between the distributions of inter- and intra-generational costs. By means of arguments that I hope are appropriately sensitive to these complexities, I shall offer a qualified defense of a principle that assigns proportionally equal intergenerational costs. In discussing proposals for the intergenerational assignment of the costs of climate change, it is important to keep in mind that CO2 emissions are associated not only with costs—the cost of adapting to or mitigating climate change—but also with benefits—the benefits of industrial activity, transportation, modern farming, recreation, heating, and cooling. Although we will have to implement means for deriving these goods that involve far fewer CO2 emissions, it is nonetheless the case that ever since the industrial revolution the activities that have generated CO2 have also produced important benefits, capital, and consumer goods that we continue to enjoy and that future generations will enjoy. Any reduction in costs for future generations will incur costs for the present and near future, and therefore predictably a reduction in certain benefits for the present and future. This is important for two reasons. One is that it is unreasonable to consider only the costs that future generations will incur from emitting activities; one has also to consider the gains in wealth that accrue to them due to our industrial activity. The second is that in the absence of a significant change in the global institutional structure, the future poor can be expected to suffer heavily in the payment of adaptation costs; and unless we construct our regulatory institutions to avoid it, the opportunity costs of mitigation will likely be especially costly to those who are presently poor. In the end one cannot really get a moral grip on the intergenerational alternatives that we face without some discussion of the intra-generational assignment of the costs and benefits of adaptation and mitigation. The realization that the intra-generational assignment of the costs of mitigation and adaptation are also matters of justice significantly complicates any discussion of the assignment of the intergenerational costs of climate change. In order to attempt headway, I discuss these matters under three different scenarios. One scenario, which I call Continued Deep Inequality or CDI, assumes that although very modest gains will be made in addressing absolute poverty, along the lines of the First Millennium Development Goal, global inequalities and attendant severe poverty will continue for the rest of the century. My second scenario, Global Justice or GJ, assumes that global inequalities and attendant severe poverty are permanently eradicated in the very near future, in the time that it would take to arrive at a new international agreement on climate change and to establish the institutions for governing it. Thus, at the inception of the new CO2 emissions reduction regime the global order is substantially just. The third scenario, which I call Progressive Inequality Reduction or PIR, assumes long-term institutional change, producing significant decreases in inequality and attendant poverty, such that by the end of this century the global economy is significantly more just than it is now. I consider the following three principles for the assignment of the intergenerational costs of climate change: Future Optimality: Present energy policy should produce an optimal sum of the foreseeable future costs and benefits of CO2 emissions. Future Sufficiency: Present energy policy should produce a sum of foreseeable future costs and benefits of CO2 emissions that at least ensures the maintenance of just political and legal institutions. Intergenerational Equality: Present energy policy should produce foreseeable future (adaptation) costs of CO2 emissions whose proportion to overall future economic output is equal to the proportion of (mitigation) costs to output of the present generation. By equalizing the proportions of costs to economic output, Intergenerational Equality allows that future persons might have more absolute costs than present persons. This would be permissible if the economic growth that our policies produced contributed to greater wealth in the future. By focusing on proportional equality and not absolute equality, then the principle can take into account the benefits of economic growth, which might be the result of polluting activity. Future Optimality could be understood in either aggregate or per capita form. One reason to take it in the per capita form is to control for population growth. Another way to control for this is to limit its aggregate application to cases in which the population is the same size. Derek Parfit calls such a version of Future Optimality The Same Number Quality Claim or simply Q: “If in either of two outcomes the same number of people would ever live, it would be bad if those who live are worse-off, or have a lower quality of life, than those who would have lived.”11 Parfit's principle is, of course, of limited value precisely because of the unrealistic constraint that the comparison sets must contain the same population size. But it is nonetheless the most discussed version of Future Optimality in the literature on intergenerational justice. James Woodward has criticized Q because of its demandingness on members of the present generation.12 This concern is directly applicable to Future Optimality in either its aggregate or per capita form because both require present sacrifices to improve maximally the well-being of future persons. They repeat, and amplify as moral principle, a general historical trend that philosophers in earlier times viewed as deeply problematic, even to the extent of requiring a theodicy if a providential understanding of history were to be salvaged. Immanuel Kant worries that “earlier generations seem to perform their laborious tasks only for the sake of later ones . . . and . . . that only the later generations will in fact have the good fortune to inhabit the building on which a whole series of their forefathers . . . had worked.”13 G. W. F. Hegel more vividly imagines the costs that the providential account has to justify when observing that history resembles “the slaughter-bench at which the happiness of peoples, the wisdom of States, and virtue of individuals have been victimized.”14 One need not assume that God is directing history to be bothered by Future Optimality. It is morally troublesome because it seems incompatible withimpartiality with respect to generational membership. It takes the interest of future persons as counting for everything, and those of the present for nothing. Privileging the interests of future persons over the present is especially problematic according the PIR scenario (stated previously) in which poor people in the future are assumed to be less poor both absolutely and relatively than those who are presently poor. The problem with Future Optimality is that it runs afoul of our intuitions regarding impartiality. It is, however, easier to identify cases in which our intuitions about impartiality are violated than it is to understand clearly what impartiality requires. In most of the remainder of this essay this will be my concern. John Rawls's employment of the original position argument is a contractualist effort at modeling deliberative impartiality. It seeks an impartial outcome by means of procedural impartiality, in particular by the parties' absence of knowledge about various aspects of themselves—their location behind the veil of ignorance. Criticisms of contractualist approaches to intergenerational justice call into question whether there is such an approach that can advance our understanding of the requirements of impartiality in the context of intergenerational justice and even whether impartiality is a desideratum of intergenerational justice.15 In this section I distinguish three versions of a broadly Rawlsian approach and argue that one is useful for present purposes. To begin with, consider the requirements for fairness in the deliberation about principles of justice for the distribution of the costs of climate change. The point of an argument based upon hypothetical consent, in contrast to actual consent, is to insulate the outcome from the manner in which real-life privileges can distort the deliberative process. Given the global scope of climate change, an appropriate original position—if there is such—employed to justify duties of justice with respect to the costs of CO2 emissions necessarily would be cosmopolitan in seeking to prevent parties from bargaining on the basis of their citizenship status. Moreover, due to the intergenerational nature of the problem of climate change, the original position also would have to prevent strategic bargaining on behalf of one's own generation. Controversy, however, surrounds the manner of construction of an original position that could prevent distortions resulting from bargaining on behalf of one's generation. Because different constructions of the original position could lead to different principles being agreed upon, the controversy is material to understanding what intergenerational justice requires. Consider then the following three possibilities for constructing an original position for intergenerational justice: Intergenerational veil of ignorance and all possible persons. Parties in the original position are (or represent) all actual persons from the present generation and all possible persons from all future generations. They are subject to a deliberative constraint of a generational veil of ignorance that renders each of them ignorant of which generation is theirs.16 Intergenerational veil of ignorance and all actual persons. Parties in the original position are (or represent) all actual persons from the present and all future generations. They are subject to a deliberative constraint of a generational veil of ignorance that renders each of them ignorant of which generation is theirs.17 Present time of entry. Parties in the original position are (or represent) all actual persons from the present generation. They are subject to a deliberative constraint of a generational veil of ignorance that renders them ignorant of the place of the generation, of which they are all members, in history. They are also subject to the constraint that they must choose only a principle that they could endorse past generations as having chosen.18 The general idea of the original position is to model deliberative fairness so that the outcome of the deliberation is distinct and can be endorsed by everyone who accepts the moral importance of fair terms of deliberation. Different versions of the original position might be appropriate for different considerations of justice. In seeking to determine which version—if any—is appropriate, we ask ourselves not only which considerations ought not to influence deliberation, but also what manner of constraint can be put on deliberation to remove the unwanted influence. In actual deliberation we approximate impartiality when we rule out appealing reasons that could not be appealed to in the original positions due to its constraints. Each of the three proposals above seeks to prevent one from rejecting principles simply because they do not favor members of one's own generation. In order to determine which principle of intergenerational justice would be selected once such influences were removed, we must determine the most sensible manner of preventing the rejection of principles that do not favor one's own generation. Consider the first proposal. In this proposal parties are ignorant of whether they are (or represent) actual or merely possible persons. Parfit claims that one cannot deliberate on the assumption that one might not exist. “We can imagine a different possible history, in which we never existed. But we cannot assume that, in the actual history of the world, it might be true that we never exist. We therefore cannot ask what, on this assumption, it would be rational to choose.”19 Parfit's point is not, I think, meant to be a psychological one, such as the problems that some people encounter when trying to reason as if they did not know their gender. Nor, if we look at the second sentence of the quotation, is the problem only one of practical deliberation. It seems rather to be an epistemic or logical problem. We cannot assume about the actual world that we never existed. If this is correct, then merely possible persons gain no representation in the original position. Parfit does not elaborate on the point. So, consider two possible lines of reasoning in support of the view. The first is Cartesian: One's activity of imagining the world commits one logically to one's actual existence. This puts a constraint on how the actual world can be imagined. Although one might imagine oneself as deliberating about principles to apply in other worlds in which one does not exist, one cannot imagine not existing in the actual world. The second is based upon the idea that justice is meant to apply to the actual world and the claim that a necessary condition of the actual world is that all and only actual persons exist in it. If any actual person's existence is a necessary condition of the actual world, and if one cannot imagine what is logically impossible, then one cannot imagine actual persons not existing in the actual world. I do not know which of these lines of reasoning—if either—Parfit would endorse. Both, however, seem plausible enough to create doubts about the first version of the original position. So, whatever the demands of impartiality are, I suppose that they cannot require us to treat similarly the interests of actual and possible persons. I turn then to the second manner of constructing the original position. This construction avoids the problem of the first by including (or representing) only actual persons, present and future. But there seems to be no non-question-begging way to arrive at principles on this construction.20 Different principles will guide different institutional schemes of regulating energy production and consumption. Within the histories of these different institutional schemes different people will meet, have sex, and rear children—for the reasons that Parfit rehearses. We cannot include actual future persons, then, unless we already assume an institutional scheme. But any scheme is in question so long as the principles that would regulate it are up for deliberation. Insofar as the constraints of the original position are meant to model our deliberations about justice, the upshot of the question-begging charge is that in our thinking about how to act in order to fulfill our duties to future generations, it makes no sense to suppose that persons who will exist are somehow fixed. Hence, whatever deliberative impartiality requires, it cannot range over both persons now living and persons who certainly will live. Jeffrey Reiman, however, endorses what appears to be this second version of the original position. “Because they do not know their generation, the parties in the original position, in effect, represent all and only those people who, from this moment on, will ever exist: people who are currently living, and future people who do not yet exist but who one day will.”21 He distinguishes between the properties of persons and particular persons. “Normally, which particular one is will determine which properties one has. However, we can distinguish these two, and say that a person's fate (whether her life turns out to be good or bad) depends on her properties and not on which particular she is as such, that is, as distinct from which properties she has.”22 Reiman maintains that future persons' rights can be violated if our actions or institutions assign them properties (such as being impoverished) that are contrary to their rights. His account allows that the particular person is contingent on the principles adopted, but that persons' interests are not contingent. From a future person's standpoint, it makes sense to think that it is in his or her interest to be born with certain properties rather than others, but it is not in his or her interest to be born this particular one rather than that particular one independent of differences in properties. Thus a future person's properties may be morally relevant now, but which particular a future person is beyond the difference in properties is not.23 In response to the question-begging charge, suppose that Reiman claimed that in our deliberations about what we owe future generations we can distinguish between our lack of knowledge about who in particular will exist—which depends on the principles chosen—and the interests that persons who will exist will have. Reiman's view would certainly be attractive if it managed to be a version of the original position that was free of the problems canvassed above. But this does not seem to be the case. For either the original position includes only actual (particular) persons or not. If it does not then, then it includes possible future persons. It therefore has the problems of the first version of the original position. If it includes only actual persons from all generations, then it is a question-begging account since the existence of persons regardless of their severability from their interests is dependent in part on which principles are selected. Reiman might counter that it is not persons, but interests that are represented in the original position. But unless we attach persons to these interests there will be no deliberation; and we do not then have a model for the impartial selection of principles. There does not seem to be a deliberative constraint that will, as it were, let future generations speak for themselves in regards to what we owe them. Given the problems associated with the first two versions of the original position, Rawls seems to have been correct in Justice as Fairness to devise the original position along the lines of the third version for matters of intergenerational justice. Similar to the other two, the third constrains deliberation so as to establish impartiality, but unlike the other two the third does not involve representing parties from future generations. It therefore does not contain the problem of either including possible future persons deliberating or of begging the question about principles by including only actual future persons. In the present time of entry version, although the parties are ignorant of their generation's place in history, they know each other to be from the same generation; and an acceptable principle is constrained by the requirement that parties can endorse its selection by previous generations. The important lesson of this version is that we achieve impartiality in our deliberations about intergenerational justice in part by binding ourselves only to principles that we would find it acceptable for previous generations to have bound themselves. With an account of how to model deliberative intergenerational impartiality in hand, I return now to the discussion of the principles of justice for the assignment of climate change-related costs. In discussing choice within an original position the constraints on the parties are decisive. According to the present time of entry interpretation, the parties—all members of the same generation—are subject to four important conditions: They do not know the place of their generation in history. They must choose only a principle that they would affirm as having bound all previous generations as well. They are indifferent to the well-being of members of other generations. They seek maximal avoidance of costs for themselves (or for those whom they represent). Just as the veil of ignorance constrains the rational pursuit of the primary goods in the intra-generational original position, so conditions (1) and (2) constrain condition (4). Rawls argues that in the intra-generational original position there would be agreement on a benchmark of equality, but that deviations from this to affirm the difference principle would be rational given the circumstances.24 In the present case, conditions (3) and (4) would incline parties to favor their own generation maximally. Condition (2), however, constrains that choice. How do these constraints play out in considering the principles of Future Sufficiency and Intergenerational Equality? Would they lead to reasonably determinate results as, arguably, does the veil of ignorance in the case of intra-generational justice? In deliberating about these principles I suppose that Intergenerational Equality guarantees Future Sufficiency, in other words that by Intergenerational Equality future generations do at least as well as they do by Future Sufficiency. So, Future Sufficiency might permit the present generation to assume fewer costs of mitigation than does Intergenerational Equality. The choice between the principles when looking forward can be seen as a choice between assuming more mitigation costs now to equalize costs between generations or allowing the possible assumption of fewer costs now so as only to ensure that just institutions are possible in the future. But when looking backward it is a choice between assuming fewer adaptation costs now because earlier generations chose to equalize or assuming greater adaptation costs now because previous generations only mitigated enough to preserve just institutions. An argument that the parties would select Intergenerational Equality over Future Sufficiency goes as follows: The parties would prefer previous generations to have maximally mitigated their climate change adaptation costs. The parties would prefer to minimize the costs of mitigating future climate change. All other things being equal, Intergenerational Equality best satisfies the preference stated in the first premise. Future Sufficiency best satisfies the preference stated in the second premise. The parties are constrained to choose only the principle that they would prefer earlier generations to have followed. The parties are constrained to select Intergenerational Equality. I call this the equality argument. Premises two and four are logically irrelevant to the argument, but they serve to illustrate the merits of the competing principle. If premise five were not there, there would be no rational grounds for choosing Intergenerational Equality over Future Sufficiency. A deliberative impasse would result. So, premise five has the virtue not only of modeling impartiality but also of producing a determinate outcome. I take the equality argument to be a pro tanto warrant for Intergenerational Equality. In effect, it amounts to claiming that if we adopt an impartial attitude toward generational membership, and thereby exclude reasons that serve only to favor one generation over another, there is good reason to endorse the principle of Intergenerational Equality, which requires not imposing climate change adaptation costs on future generations that are a greater percentage of the overall economic output than the percentage of the mitigation costs for the present generation. In the next two sections I further defend this principle by addressing objections to it. One might object to the equality argument on grounds that the deliberative constraint that parties must select only the principle that they would prefer earlier generations to have chosen (condition (2) above) favors Future Optimality since any generation would prefer that the previous ones maximally benefit it. In section II, I maintained that intuitively Future Optimality seems inappropriate because the burden that it places on those now alive does not conform to our intuitions about the requirements of intergenerational impartiality. The present objection contends that condition (2) does not in fact support our intuitions about intergenerational impartiality. This objection, however, fails to appreciate that the original position consists of practical deliberation about a principle to guide the (unspecified) present generation in relation to future generations, not a hypothetical deduction of what present persons would have liked past persons to have done. So, although condition (2) would not rule out Future Optimality if the parties were not deliberating about a principle to bind themselves, Future Optimality is ruled out by the parties' rational self-intere