CO₂ from fossil fuel burning: global distribution of emissions

The atmospheric concentration of carbon dioxide is increasing. An important source of this excess carbon dioxide is the burning of fossil fuels for energy uses. This paper describes an estimate of the areal distribution of CO₂ emissions from energy sources. CO₂ from fuel burned in international bunkers is not included nor is CO₂ from gas flaring or cement manufacture. Emissions are calculated on a 5° x 5° grid of latitude and longitude, based primarily on United Nations fuel use data. Fuel consumption data by country, by state within the US, and by province in Canada are used to calculate CO₂ emissions. Distribution of CO₂ emissions within these political entities is based on population distribution, using both discrete population data for subcountry units and population density maps. Aside from errors inherent in the UN fuel data and in our estimates for fuel composition and combustion efficiency, the major sources of error are (a) within-country regional variations in energy use per capita, (b) within-country regional variations in energy sources (e.g., hydroelectric versus coal electric), and (c) errors in our estimates of relative population density within political entities. While we believe regional patterns are accurately represented and that no CO₂ parcel is allocated very far from its correct source grid space, individual emission numbers by grid space are subject to large uncertainty. The final tabulation shows that 90% of total emissions are from the latitude band 20°-60° N, with the highest individual numbers from the grid spaces containing Frankfurt, London, and Tokyo.