Sufficientarianism and the economics of climate change

Can economics reflect climate justice? Although the scenario forecasts of climate economists are key inputs to IPCC assessments, their ethical assumptions fail to reflect important considerations of justice. This is clearest regarding sufficientarian justice, which requires that no person falls below a minimum level of well-being. This view is reflected in an important strand of climate diplomacy and activism that highlights the plight of those most vulnerable to climate harms. However, I show that sufficientarian justice is largely incompatible with predominant approaches to climate economic modelling. I then examine the prospects for a sufficientarian climate economics, considering dual discounting approaches, well-being ‘guardrails’ approaches and basic needs modelling. I find that the latter two are closest to sufficientarianism, although they reflect different interpretations of its core claims. Finally, I consider whether climate sufficientarianism requires economic ‘degrowth’, as some have claimed. I argue that sufficientarianism is compatible with periods of economic growth, but is likely to be incompatible with the indefinite pursuit of growth due to the ecological impacts this would entail. Since growth is a standard assumption in climate economics, this reiterates the need for new economic approaches in the pursuit of a just and sustainable future.