Differentiated responsibilities and prosocial behaviour in climate change mitigation.

A characteristic feature of the global climate change dilemma is interdependence between the underlying economic development that drives anthropogenic climate change-typically modelled as a common pool resource dilemma1,2-and the subsequent dilemma arising from the need to mitigate the negative effects of climate change, often modelled as a public goods dilemma3,4. In other words, in a carbon-based economy, causal responsibility for climate change is a byproduct of economic development, and is therefore endogenous to it. To capture this endogeneity, we combine these two dilemmas into a 'compound climate dilemma' and conduct a series of incentivized experiments in the United States and China to test its implications for cooperation and prosocial behaviour. Here we show that, in a differentiated development condition, even while the advantaged parties increase their prosociality relative to an endogenous but homogeneous baseline condition, the accompanying decrease in cooperative behaviour by the disadvantaged parties more than offsets it. Furthermore, compared with exogenous but identically parameterized control conditions, this endogeneity decreases cooperation in the mitigation dilemma. In light of this interdependence, the basis upon which mitigation obligations should be differentiated becomes an additional dimension of conflict, with implications for domestic politics and international negotiations discussed5,6.