PROJECTIONS OF FOSSIL FUEL USE AND FUTURE ATMOSPHERIC CO2 CONCENTRATIONS

Using Hubbert's modeling techniques, projections of future fossil fuel use are developed both for the proved reserves of world natural gas, oil and coal, and for an estimate of the ultimate recoverable fossil fuel resource. The proved reserves are comprised of 3,670 quads (10¹⁵ BTU) of natural gas, 5,760 quads of oil, and 25,520 quads of coal, the combustion of these quantities of fossil fuel will generate 8.35x10¹⁷g C (carbon) as CO₂ emissions. The ultimate recoverable fossil fuel resource is estimated to be 11,670 quads of natural gas, 20,010 quads of oil, and 134,380 quads of coal, the combustion of which would generate 3.8x10¹⁸g C as CO₂ emissions, with emissions peaking at roughly the year 2070. A history of world CO₂ emissions from 1850 to 1990 is presented for fossil fuel use, deforestation, methane, Portland cement manufacturing, and volcanic activity. These emissions are extended into the future using two fossil fuel use projections and a projection of future population growth. The low and high estimates would generate 2.1x10¹⁸g C and 5.1x10¹⁸g C, respectively, as CO₂ emissions by the year 2200. The relationship between the historical world CO₂ emissions and the historical increase in atmospheric CO₂ is examined and used to develop two models to project future atmospheric CO₂ concentrations. 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 903 ppm with the most likely value reaching 632 ppm in the year 2076 and then falling to 450 ppm by the year 2150. This work is intended to offer new approaches to investigating the issues of energy resources, energy use and global climate change. The projections show that world resources of oil and natural gas, including future discoveries, will only be able to meet demand until roughly the year 2020. Then, coal will become the dominant fuel source and is projected to be able to meet demand until roughly the year 2070. Although large quantities of CO₂ emissions will result from fossil fuel use, ocean chemistry has the capacity to remove CO₂ at rates sufficient to prevent catastrophic build up.