EMF Publications

EMF OP 48 Preliminary Results from EMF 14 on Integrated Assessment of Climate Change

Occasional Paper

John P. Weyant - Stanford University

Published by
Stanford University, 1997

A historic Framework Convention on Climate Change was signed by 154 countries at the United Nations Conference on Environment and Development (UNCED) in Brazil in June 1992. A goal of the convention was to have countries work towards stabilizing concentrations of greenhouse gases in the atmosphere at a level that would prevent undesirable anthropogenically induced effects on the climate system. Ultimately, the appropriate course of action for each country will depend on its assessment of the costs and benefits of policy intervention.

There remain large uncertainties, however, about likely greenhouse gas emission levels in the future, about the relationship between emissions of greenhouse gases and their atmospheric concentrations, about the link between atmospheric concentrations and global climate change, about the changes in climate that will occur, about the impacts of the climate change on people and ecosystems, and about how these impacts ought to be evaluated. Over the past few years a number of “integrated assessment” models that represent these links have been developed. The purpose of this EMF study was to compare the various approaches to “integrated assessment” that have been employed to assess their usefulness (and recommend areas for improvement) in policy development and in setting climate change research priorities.

The study brought together representatives of “integrated assessment” modeling teams with experts (with or without models) on each of the key individual components and linkages (e.g. carbon cycle, atmospheric chemistry, climate, energy-economics, physical impacts of climate change, valuation of impacts, etc.). Working with individuals involved in the development of policies for dealing with climate change, these groups have run mutually agreed upon standardized scenarios and have compared key outputs produced. Because of its interdisciplinary nature and the complexities involved, this study required more component by component comparisons than previous EMF studies, as well as a closer look at the way model components are currently linked, and an assessment of whether or not improved linkages/component sets can/should be developed in the future.

The full EMF 14 working group met five times: (1) in June of 1994 in Washington D.C., (2) in December of 1994 at the International Institute for Applied Systems and Analysis outside Vienna Austria; (3) in May of 1995 at Stanford University; (4) in March 1996 at IIASA, and (5) in March 1997 in Tokyo, Japan. In addition, numerous study group meetings were convened between mid-1994 and mid-1997.