However, some present environmental damage might be presently harmless, and the activities that cause this damage may even provide net benefits for present and proximate generations of human beings. Such damage might nonetheless constitute a serious threat to the interests of more distant future generations. Writing in 1977, Toby Page cites a fictional example:

You are the director of the Office of Management and Budget. A proposal reaches your desk about a riskless project which will extract energy from the sun at an increased rate for 200 years. New production processes could use the energy to triple our GNP every year until 2180. Total project costs are negligible with one exception. The sun will explode [because of the project] and end life in 2180.

(Page 1977: 250)

Even though the people who would be harmed by this project are people who don’t presently exist, it is still plausible to think that we have an obligation not to adopt present policies that doom them (along with all other living creatures) to an untimely demise. One might urge that policies that doom the distant future, or which are negligent or reckless with respect to the risks they impose in the distant future, are inappropriate and unjust because they will cause harm to future people, even though they may provide benefits for people who presently exist. While Page’s scenario is fanciful, the essential elements are similar to contemporary arguments to mitigate the effects of global climate change by reducing the level of greenhouse-gas emissions: while current and proximate generations might benefit from present consumption of fossil fuels, the associated emissions may cause terrible human and environmental damage in the more distant future (IPCC 2007). Climate policy is often presented as a trade-off in which members of the present generation are asked to forego benefits for the sake of preventing harms to future generations (Gardiner 2011; Wolf 2009a). Thus a third strategy employed to support environmental regulations urges that such regulations are a necessary or appropriate way to protect the interests of distant future persons.

This article will begin in section II with a brief discussion of the status of future generations in environmental ethics and environmental law. Sections III and IV discuss two central grounds for skepticism concerning the possibility that future generations can have rights, and articulate several different strategies to address such skepticism. Section V very briefly considers whether liberal environmentalists who accept Mill’s harm principle (or a close relative of Mill’s principle) can accept liberty-limiting environmental legislation that aims to protect the rights and interests of distant future people. Then Sections VI and VII examine the status of future persons in contemporary theories of justice, with special attention in section VII to the work of John Rawls. Because Rawls’s work focuses on needs, and on the ability of institutions to provide stable intergenerational protections for needs, section VIII evaluates several different conceptions of intergenerational sustainability, and the relationship between need, sustainability and intergenerational justice. Finally, sections IX and X consider the status of future generations in positive law, and prospects for future environmental legislation designed to guarantee just treatment for the members of distant future generations.

It is perhaps surprising that environmental ethicists have not given more careful attention to environmental obligations to future generations. Perhaps this is partly explained by the way the field of environmental ethics is often distinguished from other fields: some ethicists define the field of environmental ethics around the distinction between “anthropocentric” and “non-anthropocentric” theories. Anthropocentric theories of ethics are those theories that hold that all our obligations are, in the final analysis, obligations to other persons. Non-anthropocentric theories, by contrast, hold that we can have obligations that are not directed at persons, and that our obligation to preserve and protect environmental systems are best understood as obligations to promote the intrinsic or noninstrumental value these systems possess. Thus quite a lot of discussion in the field of environmental ethics has involved explication of the concept of intrinsic value and the development of arguments to show that environmental systems have this kind of value.

When environmental ethics is identified as the study of non-anthropocentric value systems, then consideration of our environmental obligations to future generations is excluded from consideration as a topic in environmental ethics. But many of our most important environmental obligations involve the pursuit of multiple objectives: if we pursue efforts to regulate mountaintop removal as a method of coal mining, we may, at the same time, hope to preserve mountaintop ecosystems, protect rural communities, ensure the safety of mine workers, prevent stream runoff, maintain biodiversity and promote alternative methods of energy production. Some of these objectives may be non-anthropocentric, but these will at most be a subset of the total set of motives and interests that need to be taken into account in the articulation of an appropriate policy. Even if we do have fundamental and irreducible obligations to nature (or to natural systems), and even if one holds that these obligations are based on the intrinsic value of the subject to which they are directed, we need to place these values alongside other values and other kinds of values before we can properly understand the way in which they contribute to justifying environmental laws and policies. As many contemporary environmental ethicists recognize, the fields of environmental ethics and environmental-policy analysis must address this broader range of concerns and objectives.

One salient reason for implementing policies for environmental protection is that these policies are necessary, or would be an effective way to protect the interests and perhaps to secure the rights of future people or future generations of people. But some people find it odd to think that we have obligations to people who don’t yet exist, or that their future rights might constrain present liberties. The next sections will consider key challenges to the idea that present enforceable obligations might be linked to future claimants or to future rights.

III. Skepticism About Future Rights and Present Obligations

Because future persons do not presently exist, some writers are skeptical about the idea that they might have rights or that present persons might have obligations to them. Different grounds have been expressed for such skepticism. For example, Beckerman and Pasek write:

[P]roperties, such as being green or wealthy or having rights, can be predicated only of some subject that exists. Outside the realm of mythological or fictional creatures or hypothetical discourse, if there is no subject then there is nothing to which any property can be ascribed. Propositions such as “X is Y” or “X has Z” or “X prefers A to B” make sense only if there is an X. If there is no X then all such propositions are meaningless.

(2001: 15)

If one wishes to respond to this argument in defense of the rights of future persons, there are three principal strategies one might pursue: first, one could argue, pace Beckerman, that future persons do in fact have present rights. Second, one might argue that legislation may create legal rights for future persons, even though these rights would not be associated with any antecedent moral rights. Third, one might argue that present actions can be wrong because they violate future rights—the rights that future people will possess when they come to exist.

In support of the first strategy, it should be noted that the present nonexistence of future people does not make them imaginary like fictional people: they do not exist in an alternative possible world, but in a future state of our own world. In some contexts, we refer to future individuals by the properties they will or may come to possess, as when as-yet-nonexistent children are accommodated in a will. Further, possession of a right is not like current ownership or like the possession of a property. To say that A has a right against B is simply to describe a moral relation that holds between A and B. But perhaps relations can hold between individuals who exist at different times: for example, the “prior to” relation would seem to hold wherever A exists prior to B, and present persons exist prior to future ones. If the existence of a normative relation between present and future people is more like the existence of a relation between them, then it will not follow that future persons cannot have rights merely because they suffer the temporary present embarrassment of nonexistence. While this argument does not show that future persons have present rights, it may be sufficient to undermine Beckerman and Pasek’s argument against the possibility that they could.

A third strategy, consistent with the other two, and perhaps sufficient in itself, focuses on the rights that future people will have when they come to exist. On this view, present actions may be wrong and appropriately prohibited when they are likely to violate the legal or moral rights that people will come to possess in the future (Davison 2008; Feinberg 1986). In other legal contexts, such a view concerning future rights is relatively uncontroversial. For example, consider the following:

Scheme for future theft

Before Beth’s birth, Alph works to set in place a scheme to steal money that would otherwise come to Beth as an entitlement when she reaches a certain age. As a result of Alph’s scheme, Beth’s money is later untraceably transferred to the account of Alph’s children. Many years later, long after Alph himself has died, Alph’s children innocently enjoy this windfall, unaware that it has been stolen.

It is plausible to think that Alph’s wrongful action violated some of Beth’s present rights, by changing her prospects. But it is also plausible to think that Alph’s action results in the later violation of additional rights that Beth acquires when she comes of age. If someone noticed Alph’s scheme and intervened to set things right, Alph would still have violated the earlier rights but the later rights would not have been violated at all. Obviously, legal measures that prohibit actions like these are fully justified by a legitimate interest to protect the rights that people will come to possess.

It is a short and highly plausible step to urge that present actions may be similarly wrongful when they lead to the violation of the future rights that people come to possess, even if the people who will possess these violated rights don’t exist when the wrongful actions take place. On this view, legal prohibition of such wrongful actions would be justified by the need to prevent future rights violations and their associated harms. While the present enforcement of future rights might seem hypothetical, courts have sometimes found ways to accomplish it. For example, the Philippine Constitution asserts in Article II, section 16 that, “The state shall protect and advance the right of the people to a balanced and healthful ecology in accord with the rhythm and harmony of nature.” The Philippine Supreme Court ruled in 1993, in a case to be discussed at further length in section IX, that this right belongs to future as well as present generations of Philippine citizens. The court found that timber contracts that threatened destruction of the nation’s forests were accordingly unconstitutional (Minors Oposa v. Secretary of the Department of Environment and Natural Resources (DENR) (1993) 33 I. L.M. 173). The courts of other nations have not, for the most part, found ways to follow this road, but there is no reason in principle why similar constitutional provisions or similar legislation could not be crafted to accomplish the same thing.

There is another well-known argument that is regarded by many people to call into question the idea that future persons may have rights, and even the more modest view that presently existing people may have obligations to the members of future generations. According to the nonidentity problem, present actions do not simply change the circumstances of life for future generations, they also change the constituency of future generations (Parfit 1984, ch. 16). That is, different people will exist, depending on our present choices. Any large-scale social policy will cause subtle changes in many people’s lives, and as a consequence different people will meet and different children will be born. Over time, small changes create more and more differences between the actual world and the world as it would have been if the policy had not been put in place. Eventually, it is claimed, entirely different people will exist from those who would have existed otherwise. This argument is sometimes taken to undermine the view that present actions could violate distant future rights: can one be harmed by an action without which one would not have existed at all? For the same reason, this nonidentity argument is sometimes thought to undermine the view that present actions could set back future interests.

Some people find this argument persuasive (Heyd 1992). But as a reason for skepticism about rights or obligations, it is peculiar. Typically our obligations to other people accrue to them not because of their unique genetic identities but, as Annette Baier puts it, “because of the roles they fill, roles that relate to others. For example, children, qua children have obligations to and rights against parents qua parents. My obligations as a teacher are owed to my students whoever they may be” (Baier 1981: 173). Analogously, the obligation not to roll boulders down a mountain is owed to anyone who might be passing on the path below, and do not in any way depend on the specific identities or the genetic makeup of the persons who might be harmed by such an action (Wolf 2009b: 108). To set a boulder rolling is to set in motion a causal chain of events that may cause harm. Even if the boulder roller is lucky and no one is harmed, the act is wrong because it recklessly creates a risk of harm.