Geir Bjarne Asheim

There are clear conflicts of interest between generations: the wellbeing of future generations might be undermined unless we take costly action today. Climate policies are a prime example of such costly current action with long- term future benefits: Should we incur costs today, by abating greenhouse gas emissions, in order to reduce the risk of serious and irreversible changes in future living conditions? This normative question of intergenerational equity can be addressed by imposing ethically attractive properties (called axioms) on distributions of wellbeing among generations to determine what criteria should be used for evaluating climate policies. The basic support for sustainability yielded by criteria of intergenerational equity with fixed population and certainty seems not to generalize to the relevant context of variable population and risk. Rather, with variable population and risk, a main concern becomes to avoid lives with low wellbeing, e.g. after some catastrophic future environmental degradation. The main research question is thus to investigate the tension between the seemingly innocent axioms on which criteria of intergenerational equity are based, and the seemingly unattractive implications that such criteria might lead to in the context of variable population and risk.