Sufficiency – Does Energy Consumption Become a Moral Issue?

Reducing the externalities from energy use is crucial for sustainability. There are basically four ways to reduce externalities from energy use: increasing technical efficiency (“energy input per unit energy service”), increasing economic efficiency (“internalising external costs”), using “clean” energy sources with few externalities, or sufficiency (“identifying ‘optimal' energy service levels”). A combination of those strategies is most promising for sustainable energy systems. However, the debate on sustainable energy is dominated by efficiency and clean energy strategies, while sufficiency plays a minor role. Efficiency and clean energy face several problems, though. Thus,the current debate should be complemented with a critical discussion of sufficiency. In this paper, I develop a concept of sufficiency, which is adequate for liberal societies. I focus on ethical foundations for sufficiency, as the discussion of such is missing or cursory only in the existing literature. I first show that many examples of sufficiency can be understood as (economic) efficiency, but that the two concepts do not coincide. I then show that sufficiency based on moralization of actions can be understood as implementation of the boundary conditions for social justice that come with notions of liberal societies, in particular the duty not to harm other people. By this, to increase sufficiency becomes a duty beyond individual taste. I further illustrate this in the context of the adverse effects of climate change as externalities from energy use.