Pranay Sanklecha

Many people living in highly industrialised countries and elsewhere emit greenhouse gases at a certain high level as a by-product of their activities, and they expect to be able to continue to emit at that level. This level is far above the just per capita level. We investigate whether that expectation is legitimate and permissible. We argue that the expectation is epistemically legitimate. Given certain assumptions, we can also think of it as politically legitimate. Also, the expectation is shown to be morally permissible but with major qualifications. The interpretation of the significance of the expectation is compatible with the understanding that historical emissions should count in terms of fairly distributing the benefits of emission-generating activities over people’s lifetimes but constrains the way in which we may collectively respond to climate change.

The effects of climate change will be felt far into the future, long after currently living people have stopped existing. A popular way of understanding what this means ethically is to conceptualize the issue in terms of intergenerational justice: currently living people have duties of justice toward future generations to not wrongfully harm them, or duties to reduce the risk of violating the rights future people will have when they exist. In this article I show that this depends on assumptions about the existence, identity, and number of future people. I argue for the relevance and importance of ethically investigating these assumptions; in particular of asking: should humanity continue to exist? I argue that this ethical investigation is necessary to properly and fully understand the ethical challenges that climate change creates.

Expectations play an important role in how people plan their lives and pursue their projects. People living in highly industrialized countries share a way of life that comes with high levels of emissions. Their expectations to be able to continue their projects imply their holding expectations to similarly high future levels of personal emissions. We argue that the frustration or undermining of these expectations would cause them significant harm. Further, the article investigates under what conditions people can be thought to hold legitimate expectations, in particular about permissible levels of future emissions. We distinguish differing theories of understanding these conditions, namely authority-based and justice-based theories, that each allows us to systematically distinguish between legitimate and illegitimate expectations. Furthermore, with respect to individuals’ future permissible emissions we give several reasons for holding that such theories cannot identify a particular expectation to a specific level of personal emissions as the only legitimate one. Finally, we argue that the set of legitimate expectations that people hold with respect to a just and effective solution to climate change has normative significance in at least two ways: the differing but equally legitimate expectations ought to be taken into account when justifying what could count as such a solution and when determining the just way of arriving at and implementing such a solution.

Theories of intergenerational justice are a very common and popular way to conceptualise the obligations currently living people may have to future generations. After briefly pointing out that these theories presuppose certain views about the existence, number and identity of future people, I argue that the presuppositions must themselves be ethically investigated, and that theories of intergenerational justice lack the theoretical resources to be able to do this. On that basis, I claim it is necessary to do the ‘ethics of metaphysics’ in order to fully comprehend what, if anything, we may owe future generations. I defend these claims against some important objections.