Intergenerational Justice

Marcos de Armenteras Cabot

1. General definition

Considerations of justice tend to be associated with the relationship between contemporaries. Questions concerning the correction of social inequalities, the guaranteeing of equality of opportunity, the promotion of access to resources or the fulfilment of everyone’s needs are central issues in public debate about justice. Over the past few decades, however, the literature on justice between non-overlapping generations has grown exponentially.

Intergenerational justice starts from the intuition that decisions taken in the present will decisively affect the living conditions of those who will exist in the future. Although in the political sphere we find questions with a clear intergenerational dimension –such as public debt (Süssmuth and Weizsäcker, 2006, p. 170), public pension systems (Gragera Junco, 2021), the protection of cultural heritage (Giorgallis, 2025) and the safeguarding of democratic institutions (González-Ricoy and Gosseries, 2016)– it is the questions surrounding environmental protection and sustainability (Barry, 1999), access to energy resources (Armstrong, 2021) and, above all, climate change (Page, 2006; Gardiner, 2011) that have attracted the greatest concern from this perspective.

2. What are generations?

The academic definition of ‘generation’ refers to the set of people who are of approximately the same age. Even so, there is no clear criterion for determining how many individuals must coexist in order to constitute a generation, nor when we are dealing with one generation rather than another, since a society is evidently not transformed with each birth or death of an individual.

Moreover, it is important to distinguish between age groups and birth cohorts (Gosseries, 2023, pp. 14–15). Age groups comprise individuals who share the same age at a given point in time, regardless of the historical period to which they belong. Birth cohorts, by contrast, consist of individuals born within the same time interval, normally a calendar year, although this criterion may be broadened or narrowed depending on the analytical purposes at hand.

It is also necessary to distinguish between two ways of understanding who constitutes future generations. The first regards as future only those generations that will exist once the present generations have ceased to exist. The second, broader conception considers all people who have not yet been born to belong to future generations, regardless of whether they will coexist with those currently living. From a normative perspective, this second conception is more persuasive, since it adequately captures the temporal scope of our decisions and responsibilities (Trammel, 2009, p. 23).

It is also necessary to distinguish between two ways of understanding who constitutes future generations. The first considers only those generations that will exist once the present generations have ceased to exist as future generations. The second, broader conception considers all people who have not yet been born to belong to future generations, regardless of whether they will coexist with those currently living. From a normative perspective, this second conception is more persuasive, since it adequately captures the temporal scope of our decisions and responsibilities (Trammel, 2009, p. 23).

3. The moral relevance of future generations: concept and problems

There is extensive debate about the existence of obligations towards future generations. Those who defend the moral relevance of future generations maintain that our actions will have a decisive impact on them. This impact implies a causal relationship between the action and the foreseeable harm that will occur in the future. But this is problematic, since such harm is located in a future that, by definition, cannot yet be verified. Climate science has developed complex models that project future scenarios by taking into account the accumulation of greenhouse gases, thereby establishing a causal link between the emitter and those who will suffer the resulting harm. But can one harm someone who does not yet exist?

This question gives rise to the non-identity problem (Parfit, 1984), which arises when an allegedly harmful action is at the same time the necessary condition for the existence of the person harmed. The victim of a harm must necessarily be harmed by a specific action. However, if that action is necessary for the existence of the individual, it cannot be considered to harm them, since the alternative would be their non-existence.

Another relevant objection is the one known as the ‘Repugnant Conclusion’, also formulated by Parfit (1984, p. 388). According to this argument, for any population whose members enjoy a very high quality of life, another, far more numerous population can be conceived whose members’ lives are barely satisfactory but which, in aggregate terms, produces a greater total amount of overall well-being. If this reasoning were accepted, one would have to conclude that a world made up of billions of people with minimally valuable lives would be morally preferable to another with fewer inhabitants but much higher levels of well-being. This conclusion seems deeply counterintuitive and calls into question whether utilitarian theories can offer satisfactory criteria for intergenerational justice.

A final line of discussion should be added, one that emerges when we turn to the needs of future generations. The difficulty lies in giving content to intergenerational justice without any empirical knowledge of the needs of the future inhabitants of the planet. Doyal and Gough (1991, pp. 171–190) propose a typology of needs organised across three levels: (1) basic needs, identified with health and autonomy, without which human life loses an essential condition; (2) intermediate needs, such as food, water, housing, security, education, healthcare and an adequate environment, which make it possible to guarantee basic needs (see Eco-social determinants of health); and (3) social preconditions for the satisfaction of intermediate needs, which depend on the historical and cultural context. If we accept that needs are objectifiable and universal, we can give a timeless account of what human beings need. In addition, we must incorporate two universal preconditions: a social one, namely peace, and a natural one, consisting of an ecologically balanced setting (Ribotta, 2011, pp. 280–284). This implies that needs must be met within an ecological limit that guarantees such a setting for future generations (see Limits and Ecological footprint). In this way, the extent of basic needs will always be constrained by the fulfilment of a natural precondition with respect to present and future generations.

4. Questions of distributive justice between generations

The stringency of the moral demands owed to future generations can be clarified by distinguishing between general moral obligations and obligations of distributive justice (Mosquera, 2021, p. 324). The former refer to basic duties not to cause harm and to provide assistance in situations of need –duties that derive from the moral consideration owed to every person regardless of their spatial or temporal location–. The latter pose a more ambitious demand: they are not content with guaranteeing minimum levels of protection but call for a fair distribution of the goods and burdens transmitted between generations. From this perspective, the fundamental question is not only whether we should prevent future generations from finding themselves in a situation of deprivation or vulnerability, but whether it is legitimate for the present generation to consume a disproportionate share of the available resources or to shift the costs of its current well-being onto the future (see Eco-social justice).

Intergenerational justice thus appears as a distributive problem between generations, in which what is at stake is determining which material, environmental and institutional conditions must be preserved to ensure that those who do not yet exist have equivalent opportunities to develop their own life plans. On this view, it becomes necessary to examine the main normative approaches that have sought to offer criteria for determining what we owe to future generations.

Utilitarianism holds that present decisions must be oriented towards maximising the aggregate well-being of all people, including future generations, even though this criterion may end up justifying intergenerational sacrifices that are difficult to accept. In contrast to this position, sufficientarianism argues that our main obligation consists in guaranteeing future generations the minimum conditions that allow them to lead a dignified life (Meyer and Roser, 2009) (see Good life). Given the difficulties that relational egalitarianism faces in addressing intergenerational problems (Lippert-Rasmussen, 2018, pp. 123–124), theories of indirect reciprocity ground obligations towards the future in the material, institutional and cultural inheritance received from past generations, so that each generation acquires the duty to transmit to the next that from which it has previously benefited (Gosseries, 2008a; Lema Añón, 2015). Along similar lines, the capabilities approach holds that intergenerational justice requires preserving the conditions necessary for future generations to develop fundamental capabilities and to pursue worthwhile life projects (Gómez Franco, 2020).

5. Law and justice between generations

Future generations cannot be subjects of rights because they do not yet exist (Feinberg, 1974, pp. 64–66; Gosseries, 2008b, pp. 470–471). Nevertheless, the legal system has incorporated the moral debate surrounding future generations through principles recognised in environmental law (see Ecological law). The principle of sustainable development and the principle of intergenerational equity are the two most relevant principles for giving legal expression to intergenerational justice.

The principle of sustainable development, formulated and popularised by the 1987 Brundtland Report, is defined as development capable of meeting the needs of the present without compromising the ability of future generations to meet their own. Since the end of the twentieth century, it has become established as one of the guiding principles of international environmental law. Its influence can be seen in numerous international instruments (Viñuales, 2013), from the 1992 Rio Declaration on Environment and Development to the 2030 Agenda and the Sustainable Development Goals. It has likewise been incorporated, in varying forms and with differing degrees of legal force, into numerous constitutional texts (Häberle, 2006), becoming both a criterion that guides the actions of public authorities and a governance framework intended to reconcile the demands of economic development, environmental protection, and intergenerational justice.

However, the effective realisation of this principle remains contested. Some affluent societies have achieved high levels of development at the expense both of their contemporaries and of resources that ought to be preserved for future generations. Consequently, a minority of the world’s population is responsible for a disproportionate share of environmental degradation (see Ecological harm) and greenhouse gas emissions, while enjoying high levels of material well-being in return. By contrast, a large proportion of the world’s population contributes little to such environmental impacts and yet lacks the resources needed to meet its basic needs adequately.

The principle of intergenerational equity is closely linked to the concept of sustainability and to the recognition that present decisions may have significant consequences for future generations. Following the publication of the Brundtland Report, the Advisory Committee of the project on ‘International Law, Common Patrimony and Intergenerational Equity’ drew up, in 1988, a proposal aimed at implementing intergenerational rights and obligations. The measures proposed included representing the interests of future generations in decision-making processes; creating advocates or commissioners responsible for their protection; monitoring natural and cultural resources; assessing the long-term impacts of public policies; promoting the sustainable management of renewable resources; and strengthening environmental research and education (see Eco-social education).

Brown Weiss (1989) developed this principle of intergenerational equity on the basis of the idea that each generation receives the Earth as a trustee and has a duty to conserve the diversity of resources and options available to those not yet born (see Public trust doctrine). Building on this contribution, the principle acquired growing doctrinal significance and can today be regarded as an emerging principle of environmental law. Although its roots lie in the idea of sustainable development, intergenerational equity has distinct content of its own. Whereas sustainable development seeks to reconcile economic development, environmental protection, and the satisfaction of human needs, intergenerational equity places the emphasis on the obligations that present generations owe to future generations and on the need to preserve for the latter the environmental conditions and resources that enable them to pursue their own life projects.

These principles have served as decisive interpretive criteria in novel environmental and climate litigation (see Climate litigation). Courts in different jurisdictions have drawn on environmental law when public decisions generate risks whose effects extend over the long term. In this way, they have made it possible to incorporate the temporal dimension into legal reasoning, requiring that the lawfulness of present actions also be assessed in light of their future consequences. This development represents a significant transformation of contemporary environmental law. Such principles increasingly function as frameworks that limit public discretion when current decisions may produce cumulative or irreversible harm. As a result, they help to steer legal interpretation towards a long-term perspective, integrating into decision-making the protection of environmental goods whose conservation is indispensable for present and future generations.

Bibliography:

Armstrong, C. (2021). Natural resources, sustainability, and intergenerational ethics. En S. M. Gardiner (Ed.), The Oxford handbook of intergenerational ethics. Oxford University Press.

Barry, B. (1999). Sustainability and intergenerational justice. En A. Dobson (Ed.), Fairness and futurity: Essays on environmental sustainability and social justice (pp. 93–117). Oxford University Press.

Brown Weiss, E. (1989). In fairness to future generations: International law, common patrimony, and intergenerational equity. United Nations University.

Doyal, L., & Gough, I. (1991). A theory of human needs. Macmillan.

Feinberg, J. (1974). The rights of animals and unborn generations. En W. T. Blackstone (Ed.), Philosophy and environmental crisis. University of Georgia Press.

Gardiner, S. M. (2011). A perfect moral storm: The ethical tragedy of climate change. Oxford University Press.

Giorgallis, A. (2025). The idea of protecting cultural heritage for the benefit of future generations in international cultural heritage law. International Journal of Cultural Property, 32(1), 76–99.

Gómez Franco, I. (2020). Deudas pendientes: La justicia entre generaciones. Plaza y Valdés.

González-Ricoy, I., & Gosseries, A. (Eds.). (2016). Institutions for future generations. Oxford University Press.

Gosseries, A. (2008a). Theories of intergenerational justice: A synopsis. Surveys and Perspectives Integrating Environment and Society, 1, 63–69.

Gosseries, A. (2008b). On Future Generations’ Future Rights. The Journal of Political Philosophy, 16(4), 446–474.

Gosseries, A. (2023). What is intergenerational justice? Polity Press.

Gragera Junco, J. M. (2021). Desigualdad intergeneracional y sistemas de pensiones. Isegoría, 64, 12.

Häberle, P. (2006). A constitutional law for future generations. The «other» form of the social contract: The generation contract. En C. J. Tremmel (Ed). Handbook of Intergenerational Justice. Cheltenham, United Kingdom: Edward Elgar Publishing.

Lema Añón, C. (2015). La reciprocidad indirecta y las generaciones futuras. Anuario de Filosofía del Derecho, 31, 203–226.

Lippert-Rasmussen, K. (2018). Relational egalitarianism: Living as equals. Cambridge University Press.

Meyer, L. H., & Roser, D. (2009). Enough for the future. En A. Gosseries & L. H. Meyer (Eds.), Intergenerational justice (pp. 219–248). Oxford University Press.

Page, E. A. (2006). Climate change, justice and future generations. Edward Elgar.

Parfit, D. (1984). Reasons and persons. Clarendon Press.

Ribotta, S. (2011). Necesidades, igualdad y justicia: Construyendo una propuesta igualitaria de necesidades básicas. Derechos y Libertades, 24, 259–299.

Süssmuth, B., & von Weizsäcker, R. K. (2006). Institutional determinants of public debt: A political economy perspective. En J. Tremmel (Ed.), Handbook of intergenerational justice (pp. 305–326). Edward Elgar Publishing

Thompson, J. (2010). Intergenerational justice and climate change. En A. Gosseries & L. H. Meyer (Eds.), Intergenerational justice. Oxford University Press.

Viñuales, J. E. (2013). The Rise and Fall of Sustainable Development. Review of European, Comparative and International Environmental Law, 22(1).