This paper analyzes the role of international cooperation on CO2 emissions growth in 36 OECD economies over the period 1970-2016. The indices of political globalization are the benchmark measure of international cooperation since a higher value of the index of political globalization is an indicator of collaboration in the world. The paper finds that political globalization decreases CO2 emissions growth. The findings remain robust when we consider the sub-indices of political globalization and include various controls. Also, the findings of the panel quantile regressions with the fixed-effects via the method of moments indicate that the effects of per capita income and the initial level of CO2 emissions are higher in more pollutant countries. However, the impact of political globalization on CO2 emissions is stable at different quantiles. The paper also discusses the potential implications for the role of international cooperation on climate change.