Preliminary 2006-2007 Global and National Estimates by Extrapolation

For nearly 25 years CDIAC has been issuing essentially annual updates to its data set on CO2 emissions from burning fossil fuels and manufacturing cement. Estimates for years since 1950 are based on energy data from the United Nations and cement data from the US Geological Survey. Occasionally we refer to national or other data sources when there are questionable or missing values in these primary data sets. Emissions estimates for years prior to 1950 have been constructed using a variety of sources. Collection, organization, and release of energy data by the United Nations Statistics Office is time and labor intensive and typically requires 2 to 2 ½ years after the end of a calendar year. Because of this time lag and because of wide interest in having an indication of CO2 emissions for the most recent years, we provide preliminary emissions estimates for two years more recent than the end of the UN energy data set. The formal CDIAC data set of CO2 emissions is now current through 2005 and this spread sheet offers estimates for the global total and for many of the major emitting countries for 2006 and 2007. Our experience with this process suggests that these preliminary numbers provide a good estimation of recent trends but there will be refinements in these numbers as full UN energy data become available for 2006 and 2007 and data for years up to 2005 are revised and updated. Estimates for 2006 and 2007 are based on energy data from the energy company BP. The BP energy data are published in June of each year and cover years up to the most recently completed calendar year. We use the BP data to extrapolate two additional years beyond the end of the UN energy data set. For emissions from cement we extrapolate the UN cement-production time series for two years and for emissions from gas flaring we assume that emissions are unchanged from the 2005 values.