Press Release: New Report on Discounting the Benefits of Future Climate Change Mitigation

For Immediate Release:  
December 20, 2001

Contact: Katie Mandes
703-516-4146

New Report on Discounting the Benefits of Future Climate Change Mitigation

Washington, DC - How do we compare the costs of greenhouse gas reduction measures taken today with the future benefits of these actions? How do we calculate the value of investments when benefits will continue to accrue over centuries? These are important questions, because the way we value the benefits of greenhouse gas emission reductions will guide the development of cost-effective solutions to the threat of global climate change. A report released today by the Pew Center on Global Climate Change addresses these crucial questions.

The report, Discounting the Benefits of Future Climate Change Mitigation: How Much Do Uncertain Rates Increase Valuations?, by Richard Newell and William Pizer of the independent nonprofit research institute Resources for the Future, highlights an important variable that often goes unexamined in current climate change models-uncertainty in future interest rates. Climate models incorporate discount rates to compare costs and benefits over time-in essence, they tell us how high future benefits need to be to justify spending a dollar today. Most climate models choose one rate and hold it constant over the time horizon of the model.

This study questions that conventional approach, arguing that future rates are uncertain. The authors demonstrate that acknowledging uncertainty about future interest rates leads to a higher valuation of the future benefits of reducing greenhouse gas emissions today - regardless of the initial rate one chooses. The authors conclude that, by ignoring uncertainty, current approaches used in economic modelling may be consistently undervaluing the future benefits of current climate change mitigation efforts. The report shows that including the effect of interest rate uncertainty in climate models could raise valuations of mitigation efforts by as much as 95 percent relative to conventional discounting at a constant rate.

"This report indicates that immediate action to address global climate change could yield significantly greater benefits in the long-run than conventional economic models have estimated," said Eileen Claussen, President of the Pew Center. "This information will be especially useful for policymakers as they seek to balance near-term mitigation costs with long-term economic and environmental benefits."

This report is the first to be published as a technical report in the Pew Center's economics series. The results of this work - and additional ongoing Pew Center analyses - will be incorporated into a dynamic general equilibrium model in order to better capture the full complexity of the climate change issue.

A complete copy of this report and other Pew Center reports can be accessed from the Pew Center's web site, www.c2es.org.

The full text of this report is accessible on the Internet:
Discounting the Benefits of Future Climate Change Mitigation: How Much Do Uncertain Rates Increase Valuations? Report.

###



The Pew Center was established in May 1998 by the Pew Charitable Trusts, one of the United States' largest philanthropies and an influential voice in efforts to improve the quality of the environment. The Pew Center is conducting studies, launching public education efforts and working with businesses to develop market-oriented solutions to reduce greenhouse gases. The Pew Center is led by Eileen Claussen, the former U.S. Assistant Secretary of State for Oceans and International Environmental and Scientific Affairs. The Pew Center includes the Business Environmental Leadership Council, which is composed of 37 major, largely Fortune 500 corporations all working with the Pew Center to address issues related to climate change. The companies do not contribute financially to the Pew Center - it is solely supported by contributions from charitable foundations.