The Special Report on Emission Scenarios (SRES), compiled in 2000 by the Intergovernmental Panel on Climate Change (IPCC), is a collection of forty possible global emission outcomes over the next 100 years that have served as a basis for many projections on global climate change. Unfortunately many of these scenarios have missed the mark and are no longer entirely plausible. Höök et al. have reviewed the data and have concluded that due to an over-reliance on outdated works as well as a certain unnecessary optimism with regards to mankind’s technological progression, the SRES greatly overestimates the amount of recoverable fossil fuels that will be available to humanity through the year 2100. This has ramifications not only for the overall economic outlooks projected by the SRES, but also for the report’s estimates of total greenhouse gas output, as the burning of fossil fuels accounts for about 57% of anthropogenic greenhouse gas in the atmosphere. Therefore, the SRES needs to revise downwards its estimates of total CO2 in the atmosphere for all of its scenarios to compensate for its overstatement of available resources.¾Steven Erickson
Höök, M., Sivertsson, A., Aleklett, K., 2010. Validity of the fossil fuel production outlooks in the IPCC emission scenarios. Natural Resources Research, 63–81
Höök et al. reviewed not only the projections for fossil fuel production provided by each of the 40 SRES emissions scenarios and the assumptions made and research used in reaching these projections, but also the relevant literature and statistics that have been published since the SRES’s 2000 publication. After this review they concluded that the IPCC had been overly optimistic about the amount of fossil fuels that could be viably extracted within the next century, and had therefore overestimated the amount of CO2 emissions possible during that time period. Many of the scenarios seem to project the recovery of more fossil fuels than are currently thought to exist, place too much weight on the quantity and feasibility of unconventional fossil fuel reserves, and put unreasonably large demands on the growth of fossil fuel production capacity of several hydrocarbon rich countries.
The authors believe that these errors stem from the SRES taking an optimistic view of future oil production supported by Rogner (1997) and Gregory and Rogner (1998) and economists Adelman and Lynch (1997). These sources essentially took the viewpoint that we should not look at oil reserves as a fixed quantity, but rather a fluid amount linked directly to our technical knowledge, with the implication that as our technology progresses, our ability not only to use fossil fuels more efficiently, but also to extract unconventional fossil fuels such as coal-bed methane or oil contained in oil shale which were once not viable, will allow us to extend our production of fossil fuels almost indefinitely.
Höök et al., on the other hand, identify various studies that show that the depletion of fossil fuel reserves increases costs enough to offset any gains from new technology, a fact that the SRES seems to ignore.
They also identify studies that show that the worldwide production of unconventional oil would be required to attain a growth rate of 10% per year for the next 20 years (de Castro et al., 2009) in order to meet SRES projections, which according to Höök and others in 2009 is a feat that has never been attained by any energy system in history.
Finally, the authors point out that even the quantity and economic viability of unconventional fossil fuels may be in question. The SRES uses scant detail to assume that coal-to-liquid technology, supposedly a key player in the sustained usage of fossil fuels, is much cheaper than current literature would suggest. Moreover, the estimated quantity of gas hydrates, another key unconventional fossil fuel, have recently decreased by three orders of magnitude, from 1018 m3 to 1015 m3, due largely to an increase in geological knowledge. This means that many of the sources used by the SRES have become obsolete and that the conclusions based on those sources are suspect at best.
The authors purport that all of these factors necessitate numerous revisions downwards in regards to the expected output of fossil fuels, and that already several scenarios contained in the SRES can be ruled out. If the IPCC would like to avoid such exaggerated figures on resource availability in the future the authors suggest that the IPCC would do well to hire more resource experts the next time around.