(b) Measuring Methods: The lifetime of fuel resources in terms of the resources-to-
production ratio is computed by dividing the total energy resources of a commodity at
the end of a year by the total production of that commodity in that year.
(c) Limitations of the Indicator: The rate of use of energy resources depends on
many factors, including economic conditions, prices, technological progress and
exploration efforts. Therefore, this indicator represents only a relative measure of
resource availability.
(d) Alternative Definitions/Indicators: The total resources and depletion rate are
alternative definitions for this indicator.
ASSESSMENT OF DATA (a) Data Needed to Compile the Indicator: Data on available energy resources and
production.
(b) National and International Data Availability: Data on fossil fuel resources are
available from the annual publication Survey of Energy Resources by the World
Energy Council and are subject to frequent revision. Data on uranium resources are
available from joint publications of the International Atomic Energy Agency (IAEA)
and the Nuclear Energy Agency (NEA). Data are also available from national and
international oil and gas companies.
REFERENCES • NEA/IAEA, various editions. Uranium: Resources, Production and Demand. Paris, France: Nuclear Energy Agency (NEA)/International Atomic Energy
Agency (IAEA).
• UNDP/UNDESA/WEC, 2000, World Energy Assessment. New York, USA:
United Nations Development Programme.
• UNSD, various editions. Energy Statistics Yearbook. Published annually. New
York, USA: United Nations Statistics Division.
• WEC, various editions. Survey of Energy Resources. Published annually.
London, UK: World Energy Council.
