Carbon dioxide is understood to be the most important greenhouse gas believed to be altering the global climate. This article applies world-system theory to environmental damage. An analysis of 154 countries examines the contribution of both position in the world economy and internal class and political forces in determining a nation's CO2 intensity. CO2 intensity is defined here as the amount of carbon dioxide released per unit of economic output. An inverted U distribution of CO2 intensity across the range of countries in the global stratification system is identified and discussed. Ordinary Least Squares regression suggests that the least efficient consumers of fossil fuels are some countries within the semiperiphery and upper periphery, specifically those nations which are high exporters, those highly in debt, nations with higher military spending, and those with a repressive social structure.