Analysis of Ultimate Fossil Fuel Reserves and Associated CO2 Emissions in IPCC Scenarios

The Intergovernmental Panel on Climate Change (IPCC) commissioned a special report on emissions scenarios in 2000 so as to forecast global carbon dioxide (CO₂) emissions for a variety of assumptions. These scenarios have been subjected to a multitude of criticisms, alleging overoptimistic predictions for fossil fuel production rates. Intrigued by this controversy, this paper employs the Hubbert linearization technique to solve for ultimately recoverable resources (URR) of fossil fuels for six significant IPCC scenarios. The predictions are substantially higher than geological URR estimates found in recent literature, ranging from 19 to over 200% higher for oil, 16 to over 500% for coal, and 171 to over 500% for natural gas, depending on the scenario. Subsequently, the atmospheric CO₂ concentrations resulting from full consumption of URR related to IPCC data, as well as literature-based URR, are determined with a simple model. The former concentrations range from 640 to over 1,300 ppm. In comparison, the peak-based URR in the literature yield 463–577 ppm. All of these figures are higher than the 450 ppm ‘threshold’ which some see as critical. Therefore, despite peaking fossil fuels, concern over climate change is still warranted. At the same time, the fossil fuel production inputs to the IPCC’s CO₂ emissions models appear predominantly overoptimistic, which calls into question the accuracy of the climate change assessment outputs. Moving forward, the IPCC is encouraged to re-assess its fossil fuel forecasts, incorporating more reasonable scenarios for peak production of fossil fuels.