Global convergence in per capita CO2 emissions

Climate change is now widely recognized as the major environmental problem. In order to reduce CO2 emissions so as to cope with climate change, a wide range of effective policies, and an enforced international cooperation are required. A better understanding of the dynamic changes of CO2 emissions will strengthen international cooperation and provide necessary information for policy making. This paper investigates the global convergence in per capita CO2 emissions over the period 1971–2008. The results manifest an absolute convergence within subsamples grouped by income level, while provide little evidence of absolute convergence in the full sample containing 110 countries. Furthermore, this paper takes the GDP per capita into consideration within the conditional convergence framework. Interestingly, the result shows that, within different income groups, the relationships between GDP per capita and per capita CO2 emission growth are different. Specially, per capita CO2 emissions of high-income countries keep at the “steady state” as income rises. This result is contrary to Environmental Kuznets Curve, which indicates that the CO2 emissions will decline when income rises beyond a certain level.