ECO4: Reserves-to-production ratio Brief Definition Ratio of energy reserves remaining at the end of a
year to the production of energy in that year. Also,
lifetime of proven energy reserves or the
production life index
Units years
Alternative Definitions Total reserves
Depletion rate of reserves
Agenda 21 Chapter 4: Consumption and production patterns
POLICY RELEVANCE (a) Purpose: The purpose of this indicator is to measure the availability of national
energy reserves with respect to corresponding fuel production. Reserves are generally
defined as identified (demonstrated and inferred) resources that are economically
recoverable at the time of assessment. Reserves are also defined as those quantities
that geologic and engineering information indicates can be recovered with reasonable
certainty in the future from known or identified energy resources under existing
economic and technical conditions The indicator considers fuels such as oil, natural
gas, coal and uranium, and provides a relative measure of the length of time that
proven reserves would last if production were to continue at current levels.
(b) Relevance to Sustainable Development: Availability of energy fuel supplies is a
key aspect of sustainability. This indicator provides a basis for estimating future
energy supplies with respect to current availability of energy reserves and levels of
production. The proper management of proven energy reserves is a necessary
component of national sustainable energy programmes.
(c) International Conventions and Agreements: None.
(d) International Targets/Recommended Standards: None.
(e) Linkages to Other Indicators: This indicator is linked to indicators of annual
energy production, annual energy use, imports, prices and resources.
