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Compendium on methods and tools to evaluate impacts of, and vulnerability and adaptation to, climate change

Historical or Geographic Analogs: Forecasting by Analogy

This qualitative tool is a method for evaluating the effectiveness of potential adaptation strategies by comparing observed adaptations to past climate extremes in different geographic locations, sectors, or time periods. This method compares events that have had a similar effect in the recent past to the likely impact of future events associated with climate change, assuming that lessons can be learned from such past experience and then applied to future situations.

These compared situations can generally share several important characteristics such as time scale, severity, reversibility, impacted sector, or aggravating factors, and point out how well actual adaptation response worked or did not work.

Appropriate Use This approach is useful during the initial survey stages of evaluating adaptation strategies to avoid duplicating research or to narrow the list of feasible options, and is generally used in conjunction with a quantitative evaluation of adaptation options. This approach does not provide a method to weigh the trade-offs among different adaptation options, but instead provides insight into how the adaptation process may work. Also, an example of adaptation in one place at a particular time is not always applicable to a future adaptation at a different place. This approach has not seen extensive use recently.
Scope All locations; all sectors; national or site-specific.
Key Output A broad perspective on previous research and attempted strategies used to address similar situations.
Key Input General information on other adaptation issues: research done, approaches used, problems encountered. Often performed by a multidisciplinary panel of experts, including relevant members of the research community such as climatologists, meteorologists, hydrologists, entomologists, and epidemiologists.
Ease of Use Relatively easy to use, although the robustness of the comparison depends on the extent of the user’s knowledge of the situations being compared.
Training Required Requires a background understanding of the adaptation issues being compared
Training Available Contact Michael Glantz for more information
Computer Requirements None
Documentation Glantz, M., and J. Ausubel. 1998. Impact assessment by analogy: Comparing the impacts of the ogallala aquifer depletion and CO2 induced climate change. In Societal Responses to Regional Climate Change: Forecasting by Analogy. M. Glantz (ed.). Westview Press, Boulder, CO, USA.

Used in U.S. EPA-supported project on analogous forecasting of the societal responses to the regional impacts of global warming. Also used to evaluate fisheries in Poland, Mexico, and the Far East.

Contacts for Framework, Documentation, Technical Assistance

Michael Glantz

University Corporation for Atmospheric Research, P.O. Box 3000, Boulder, CO 80303 USA; Tel: +1.303.497.8117; e-mail:

Cost Low cost to obtain documentation

Glantz, M. (ed.). 1998. Societal Responses to Regional Climatic Change: Forecasting by Analogy. Westview Press, Boulder, CO, USA. Coastal: Hands, E.B. 1983.

The Great Lakes as a test model for profile responses to sea level changes. In CRC Handbook of Coastal Processes and Erosion, Komar, P.D. (ed.). CRC Press, Boca Raton, pp. 167-189.

N. Mimura and H. Nobuoka. 1995. Verification of the Bruun Rule for the estimation of shoreline retreat caused by sea-level rise. In Coastal Dynamics 95, W.R. Dally and R.B. Zeidler (eds.). American Society of Civil Engineers, New York, pp. 607-616.

Parkinson, R.W. (ed.) 1994. Sea-level rise and the fate of tidal wetlands. Journal of Coastal Research 10:987-1086.

Health: FAO. 1998. An El Niño Primer. FAO Rome. (

Jury, M.R. 1996. Malaria forecasting project. In Workshop on Reducing Climate-Related Vulnerability in Southern Africa. Victoria Falls, Zimbabwe, October 1-4, 1996. SADC/NOAA/NASA. NOAA, OGP, Silver Spring, MD, USA.