In the past two decades, income inequality has steadily increased in most developed nations. During this same period, the growth rate of CO2 emissions has declined in many developed nations, cumulating to a recent period of decoupling between economic growth and CO2 emissions. The aim of the present study is to advance research on socioeconomic drivers of CO2 emissions by assessing how the distribution of income affects the relationship between economic growth and CO2 emissions. The authors find that from 1985 to 2011, rising income inequality leads to a tighter coupling between economic growth and CO2 emissions in developed nations. Additionally, the authors find that increases in the top 20 percent of income earners’ share of national income have resulted in a larger association between economic growth and CO2 emissions, while increases in the bottom 20 percent of income earners’ share of national income reduced the association between economic growth and CO2 emissions.