L’etica del cambiamento climatico alla prova dell’inefficacia causale individuale: discutendo la libertà collettiva di emissione di gas serra rispetto all’obiettivo di 1.5°C

In this article we address the so-called argument of «individual causal inefficacy» (ICI), according to which CO2-emission-generating actions are morally neutral with regards to climate change, in so far as, taken in their singularity, they are neither sufficient nor necessary to cause climate change. In the first part, we address the main substantive objection to ICI: if a single emission, analysed in isolation, does not cause any disutility, it is impossible to explain why climate change (which is the result of a sum of emissions) is the source of an enormous disutility; thus, ICI should be rejected in so far as it leads to a conclusion that is logically inconsistent. We argue, contrary to this, that it is possible to hold together ICI and individual moral responsibility for climate change, given the characteristics of the natural carbon cycle and of net-zero emissions. In the second part, accordingly, we propose a theory of individual responsibility for climate change which is based on the distinction between individual and collective freedom to emit, compatibly with a given mitigation target. This theory allows us to maintain that there exists a moral duty to reduce individual emissions, without having to demonstrate the fallacy of ICI. This duty is based on distributive reasons, which can prescind from the direct causal relationship between individual polluting actions and climate damage.