PurposeTo investigate whether CO2intensity falls at a diminishing rate as countries grow richer.Design/methodology/approachRegression of CO2intensity on the gross domestic product (GDP) per capita, including squared and cubic terms, for a panel of countries and individual countries.FindingsCO2intensity falls at a diminishing rate as countries grow richer.Originality/valueMany studies have found that CO2intensity falls with GDP per capita, but whether it does so at a diminishing rate has not been investigated. This result suggests that structural changes in GDP (more services) as countries get richer will provide little or no help toward decarbonization. It is shown that the extraction of minerals critical for industrial production has increased on par with real GDP. This could explain why CO2emissions fall at a diminishing rate.