Gustaf Arrhenius

Climate ethics and future generations

The overarching question of this research program is to investigate what we should do with regard to climate change given that our choices will not just have an impact on future generations but also determine who and how many people will exist in the future. Informed decision-making about climate change policy requires not just an understanding of scientific facts, it also requires a firm grasp of the values and normative principles at stake. Should we for example aim for a smaller or larger population? How much ecological space and other natural resources should we save for people who will live long after we die? Such questions pose a great challenge to our ordinary principles of justice and value, since they haven’t been designed with future generations in mind. The guidance offered by these theories in relation to future people is often unclear or counterintuitive, and sometimes even paradoxical. Bringing together a group of outstanding philosophers and social scientists, this programme will explore the values and principles that should govern intergenerational relations. It will investigate important theoretical and practical problems in population ethics, the theory of justice, and climate ethics. In order to facilitate compliance with principles, the programme will also investigate under what circumstances laypersons care more or less about future people and climate change and when they are willing to make a sacrifice for the sake of future people.
Final report
Purpose and development of the programme

The primary objective was to integrate and develop the most important insights regarding climate ethics from different subject areas and methodologies. It has merged normative research from philosophy, economics, and political science with empirical research from economics, sociology, and demography. A research environment was created in which climate ethics researchers from all over the world worked together across academic disciplines. The programme has established Institute for Futures Studies (IFFS) as a world leading hub for climate ethics research.


The programme’s core team comprised 33 researchers, about half based at IFFS. Interdisciplinary collaboration and dissemination of results was promoted by in-person meetings at IFFS and video meetings. The programme conducted 32 workshops and four scientific conferences. All members of the core research group, along with many external scholars, regularly visited IFFS, which worked as the hub for the international team of researchers. The programme was led by PI Gustaf Arrhenius and two Co-PIs, Krister Bykvist and Göran Duus-Otterström, backed by a project coordinator. A steering committee, including the programme’s junior researchers, oversaw the day-to-day activities and convened monthly.

Results and conclusions

The questions addressed in the programme can be divided into three themes: (1) Population Ethics; (2) Climate Justice; and (3) From Theory to Practice. Below is a brief description of some significant results within each of these areas.

1. Population Ethics

The overarching question concerned how to value future lives in decision-making processes and in future scenarios where the number of people, their welfare, and their identities vary. This issue was examined in light of impossibility theorems in population ethics which shows that there is a contradiction in our core beliefs in this area, rendering them impotent for guiding actions. The programme explored innovative approaches to navigate around this challenge. Most results have been negative. One result is that the introduction of uncertainty in population ethics does not help us avoid the impossibility results. The original impossibility results are equally problematic for evaluating climate policy measures involving uncertainty and risk. Additionally, new impossibility results emerge.

A more promising result is that the paradoxes can be avoided by limiting the number of feasible alternatives, which also is a more realistic assumption. The question is how such limitations can be justified, a previously unexplored issue, and the programme found promising results here that opens up for new research. The programme has also examined the methodological status of the conditions for acceptable theories that generate the impossibility results. In these results, the conditions are seen as something a theory either meets or doesn’t meet. The programme explored an alternative perspective where the conditions are viewed as ideals that a theory can realise to a lesser or greater extent. This approach mitigates the consequences of the impossibility theorems, as some theories fulfil the conditions to a higher degree than others and should therefore be prioritized as guiding principles.

The programme has conducted innovative surveys about people’s views regarding climate ethics. The programme ran surveys in Sweden, Spain, China, and Korea, and found significant public concern for future generations and that people doesn’t discount future people’s well-being as such, but also widespread distrust in the benefits of future-oriented policies. The conclusion is that people do care for future generations but don’t trust governments to follow through with future oriented policies. This has important policy implications.

2: Climate Justice

The focus was on how the benefits and burdens in managing the climate crisis should be distributed in a just manner both within and between generations. The programme explored various historical principles for responsibility allocation, such as the principle that the polluter or the beneficiary pays. A key result is that these principles are more robust against objections than commonly assumed and thus gives support to the idea that climate justice at least partially involves corrective justice, that is, redress.

The programme has also made progress concerning the right to emit greenhouse gases. The research has resulted in new arguments for both emissions egalitarianism and emissions sufficientarianism and demonstrated that the debate between these principles is largely determined by whether one starts from a predefined carbon budget or not. Furthermore, the programme has explored arguments for counting emissions at the point of final consumption. A significant finding here is that although consumption-based emissions accounting is more distributively just, as it would assign greater responsibility to wealthier actors, there are reasons to be concerned about its environmental effectiveness, in part because it would place more emissions beyond the direct regulatory reach of states.

The work on how the interests of future people should be addressed in democratic decision-making followed two tracks: firstly, investigations of principles for democratic inclusion and secondly, explorations of ways to make democracies more sensitive to the interests or political preferences of future persons. A result was that institutional reforms such as ombudsmen or future councils are not sufficient to achieve long-term thinking since the root causes of short-termism also need to be addressed. For example, longtermism is likely to require both that people are provided with a secure economic situation and that the discounting of future wellbeing in decision-making stops. An interesting formal finding was that the influential all-affected principle for democratic inclusion could, when applied across generations, lead to the ‘repugnant conclusion’, a well-known problem in population ethics. This unveils an unexpected connection between democratic theory and the field of population ethics.

3: From Theory to Practice

The question here were primarily how we should act when uncertain about which theories to apply; what are the demographic consequences of climate changes and vice versa; and how can people’s environmental values and attitudes be changed?

The first question has been extensively explored and a book on the subject was published within the project. The researchers developed a new theory regarding how to act under moral uncertainty and applied it to cases in climate ethics where there is uncertainty about how to value future lives and the value of changes in population size.

Regarding the second questions, the programme’s demographers created a model illustrating the interdependence of population size, population growth, and welfare. A further finding, based on uncontroversial assumptions in demography, shows that if everyone reproduces over the replacement level, that will rapidly yield great inequalities with respect to the reproductive opportunities of future generations. This observation stands in contrast to the prevalent ethical belief in a universal right to reproduce.

Regarding the last question and focusing on policies for reducing either global warming or public debt, an important finding is that political trust operates on attitudes by shaping people’s (a) confidence in policies’ effectiveness and (b) willingness to sacrifice for others. The influence of political trust outweighs that of subjective concern, while, surprisingly, discounting has so little impact that people who expect future generations to be richer are more, not less, willing to sacrifice. This suggests that it is important to promote political trust in order to motivate people to make sacrifices for the future.

New research questions

Many new and exciting research questions have emerged from the programme, as evidenced by the fact that it has generated nineteen major spin-off projects. These are new research projects that have received external funding to further explore the questions and research environment created by the programme. Some examples are:

The effect of climate change on non-human animals; how to manage catastrophic climate risk; severe empirical uncertainty; how should individuals, groups, and states coordinate their actions to mitigate climate change; ethical questions concerning the positive discount rate used in integrated assessment models; the feasibility and efficacy of so-called climate clubs.

Dissemination and collaboration

The program's research has been disseminated through 231 scientific articles, 70 chapters in anthologies and handbooks, and over 300 scientific presentations. Eleven scientific books have been published or accepted for publication, including Population Ethic, Moral Uncertainty, and What We Owe Future People, by OUP. Six anthologies with selected scientific articles from the program have been compiled, printed, and made freely available. The program's website,, and newsletter has been efficient channels for distributing materials and for communicating news to the rest of the academic world.

The researchers have been actively participating in outreach activities, resulting in over 200 interviews, panel discussions, lectures, and op-eds. Led by IFFS editor Magnus Linton the popular book Klimat och moral was published by Natur & Kultur in 2021. The program has also collaborated and organized open events with, among others, Fri Tanke, Internetstiftelsen, Klimatpolitiska rådet, and Almedalen. In a notable collaboration with the art world, the researchers participated in the creation of the 8-meter high performative sculpture Tipping Point. At the international environmental conference Stockholm +50, the program organized a seminar series in collaboration with Formas and the Global Challenges Foundation.
Grant administrator
Institutet för Framtidsstudier
Reference number
SEK 40,930,000
RJ Programmes