In this paper, per capita CO2 convergence among the EU-25 countries between 1920 and 2007 is analysed using the distribution dynamics approach. Furthermore, the analysis is complemented by investigating the asymptotic half-life of convergence, mobility indices and the continuous version of the ergodic distributions. The novel aspect of this work consists in the fact that it examines whether patterns could differ if weighted by either the population of each country or their economic sizes. The unweighted analysis indicates that the convergence patterns differ strongly before and after World War II, with more convergence being displayed after the seventies. Results of weighting both by population and by economic size show that convergence is much faster when these features are introduced into the model. Conclusions from this analysis are important for the environment policy adopted across the EU-25 countries.