Cumulative Carbon and Just Allocation of the Global Carbon Commons

Recent research has shown that the effect of human activities on climate can be characterized by a single statistic, called cumulative carbon. This statistic is the aggregate amount of carbon emitted in the form of carbon dioxide by activities such as fossil fuel burning and deforestation over the entire time such activities persist. In this paper the concept is used to address the question of fair allocation of carbon emissions amongst nations or other emitting units. It is concluded that even if emissions prior to the year 2000 are left out of the accounting, North America would have a just obligation to cease emissions completely in thirteen years, even if the emissions rate were froZen at its current level. China, India, and other developing nations could continue emissions for much longer before exhausting their fair share of the Carbon Commons. If historical emissions are fully taken into account, North America exceeded its fair share of usage in 1970, and has been in carbon overdraft ever since, whereas none of the major nations of the developing world have yet exceeded their fair shares. It is concluded that, based on principles of human equality, North America, and in particular the US, has a strong moral obligation to take the lead in actions that will ultimately reduce global carbon emissions. Western Europe has similar obligations, but has begun measures to take on a fair share of responsibility for emissions reduction, whereas such action has been largely absent in North America