Projections of fossil fuel use and future atmospheric CO2 concentrations

Abstract

Using the published record of atmospheric CO 2 levels from 1743 to 1990 and the published record of world anthropogenic CO 2 emissions from 1860 to 1990 for fossil fuel use, deforestation, biological methane production and cement manufacturing, the Future Atmospheric CO 2 Model (FAC Model) is developed that projects future atmospheric CO 2 levels. Projections of future anthropogenic CO 2 emissions, also developed in this paper, are the input to the FAC Model determining the projections of future atmospheric CO 2 levels. Published data from 1990 to 2001 are used to test the FAC Model. When published anthropogenic CO 2 emissions from 1990 to 1999 are entered into the FAC Model, the projection of atmospheric CO 2 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 CO 2 emissions and combined with projections of CO 2 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 CO 2 emissions and proved reserves plus an estimate of future discoveries of world fossil fuel are used to develop a high estimate of future anthropogenic CO 2 emissions. The two estimates of future anthropogenic CO 2 emissions are put into the FAC Model to generate future atmospheric CO 2 levels. The scenarios presented in this study define a range of anthropogenic impact on atmospheric CO 2 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 CO 2 levels will rise above 650 ppm.