There is an interesting paper available for download from P.A. Kharecha and J.E. Hansen of NASA GISS and Columbia Univ. Earth Institute on the effects of the “peak oil” on the atmospheric CO2 and climate. A good summary of the paper with many charts and scenarios can bei found in The Oil Drum.
P.A. Kharecha / J.E. Hansen: We suggest that, if estimates of oil and gas reserves by the Energy Information Administration are realistic, it is feasible to keep atmospheric CO2 from exceeding approximately 450 ppm, provided that future exploitation of the huge reservoirs of coal and unconventional fossil fuels incorporates carbon capture and sequestration.
Existing coal-fired power plants, without sequestration, must be phased out before mid-century to achieve this limit on atmospheric CO2. We also suggest that it is important to “stretch” oil reserves via energy efficiency, thus avoiding the need to extract liquid fuels from coal or unconventional fossil fuels. We argue that a rising price on carbon emissions is probably needed to keep CO2 beneath the 450 ppm ceiling.