Demographic Change, Carbon Convergence and Climate Policy

Per capita carbon emissions are an important concept in international negotiations of
climate policies and also in future projections of aggregate carbon emissions. This paper
argues that the convergence studies on per capita carbon emissions in the literature are
theoretically biased because demographic structure is not considered. The paper
therefore links demographic change to carbon convergence analysis and examines
historical convergence of per capita carbon emissions for a global sample of countries
over the period of 1960-2014. The results show that although demographic structure
does not change the existence of carbon convergence, the growth of worker shares is
significant in most estimations in this paper, and it also affects the estimates of the
convergence speed. The time period of empirical analysis also matters for the
convergence results. The paper further extends the IPAT identity by introducing
demographic structure as well as economic and energy structure, and argues that the
convergence of per capita carbon emissions depends on the convergence of each
component, and each component may converge within different time horizons. The
paper proposes that emissions rights should be allocated across countries based on a
mix of long-term, medium-term and short-term rules.