Projections of fossil fuel use and future atmospheric CO2 concentrations

Using the published record of atmospheric CO2 levels from 1743 to 1990 and the published record of world anthropogenic CO2 emissions from 1860 to 1990 for fossil fuel use, deforestation, biological methane production and cement manufacturing, the Future Atmospheric CO, Model (FAC Model) is developed that projects future atmospheric CO2 levels. Projections of future anthropogenic CO2 emissions, also developed in this paper, are the input to the FAC Model determining the projections of future atmospheric CO2 levels. Published data from 1990 to 2001 are used to test the FAC Model. When published anthropogenic CO2 emissions from 1990 to 1999 are entered into the FAC Model, the projection of atmospheric CO2 concentrations is parallel to but 2 ppm higher than the instrumental record from Mauna Loa, Hawaii. World fossil fuel production is modeled using Hubbert's Resource Model (HR Model) and projected into the future. These projections are converted to CO2 emissions and combined with projections Of CO2 emissions for deforestation, biological methane production and cement manufacturing to form the input to the FAC Model. Proved reserves of world fossil fuel are used to develop a low estimate of future anthropogenic CO2 emissions and proved reserves plus an estimate of future discoveries of world fossil fuel are used to develop a high estimate of future anthropogenic CO2 emissions. The two estimates of future anthropogenic CO2 emissions are put into the FAC Model to generate future atmospheric CO2 levels. The scenarios presented in this study define a range of anthropogenic impact on atmospheric CO2 from the low value of 453 ppm to a high value of 632 ppm in the year 2076 and then falling to 450 ppm by the year 2150. The FAC Model predicts that it is unlikely atmospheric C02 levels will rise above 650 ppm.