AN ASSESSMENT OF WORLD HYDROCARBON RESOURCES

Assessments of global coal, oil, and natural gas occurrences usually f ocus on conventional hydrocarbon reserves, i.e. those occurrences that can be exploited with current technology and present market condition s. The focus on reserves seriously underestimates long-term global hyd rocarbon availability. Greenhouse gas emissions based on these estimat es may convey the message that the world is running out of fossil fuel s, and as a result, emissions would be reduced automatically. If the v ast unconventional hydrocarbon occurrences are included in the resourc e estimates and historically observed rates of technology change are a pplied to their mobilization, the potential accessibility of fossil so urces increases dramatically with long-term production costs that are not significantly higher than present market prices. Although the geog raphical hydrocarbon resource distribution varies significantly, a reg ional breakdown for 11 world regions indicates that neither hydrocarbo n resource availability nor costs are likely to become forces that aut omatically would help wean the global energy system from the use of fo ssil fuel during the next century.