The objective of this paper is to review previous research on convergence of carbon dioxide emissions among countries. We discuss the key findings in this work, how the choices of model, data, statistical tests, etc. influence the results, and highlight some policy implications. The empirical research on convergence in per capita carbon dioxide emissions shows some evidence of convergence between developed (OECD) countries, while at the global level there appear to be relatively persistent gaps or divergence. These results are however sensitive to the choice of econometric approach and data set (e.g., the length of the time series). Still, the empirical basis for an egalitarian rule of equal per capita emissions in the design of global climate policy is not solid; it ignores the specific structural characteristics of countries such as climate, natural resource endowments, etc. The analysis therefore points to a need for more in-depth analyses of the structural determinants of carbon intensity (productivity) at the country level, as well as to additional research on the economic consequences of different types of equity principles (including combinations of such principles).

There is a rich empirical literature testing whether per capita carbon dioxide emissions tend to converge over time and across countries. This article provides a meta-analysis of the results from this research, and discusses how carbon emissions convergence may be understood in, for instance, the presence of international knowledge spillovers and policy convergence. The results display evidence of either divergence or persistent gaps at the global level, but convergence of per capita carbon dioxide emissions between richer industrialized countries. However, the results appear sensitive to the choice of data sample and choice of convergence concept, e.g. stochastic convergence versus β-convergence. Moreover, peer-reviewed studies have a higher likelihood of reporting convergence in carbon dioxide emissions compared to non-refereed work. POLICY RELEVANCE The empirical basis for an egalitarian rule of equal emissions per capita in the design of global climate agreements is not solid; this supports the need to move beyond single allocation rules, and increase knowledge about the impacts of combined scenarios. However, even in the context of the 2015 Paris Agreement with its emphasis on voluntary contributions and ‘national circumstances’, different equity-based principles could serve as useful points of reference for how the remaining carbon budget should be allocated.