This article examines what role natural factors play in explaining cross-country differences in carbon dioxide emissions. Natural factors mean here differences in the climatic conditions. the availability of renewable and fossil fuel resources and the transportation requirements of countries. While income remains the main variable. regression results shock that natural factors contribute significantly to an explanation of cross-country differences in carbon dioxide emissions. Furthermore. drastic differences in natural conditions can lead to substantial differences in predicted emission requirements for individual countries at approximately the same level of income.