The Importance of Sound Science in Public Policy
Climate scientists—and experts in related fields—will continue their research to refine our understanding of the Earth's complex atmospheric system. However, despite the advances they have made, or perhaps because of them, climate science itself is under increasing attack in some media and policy forums. Ultimately, the best way to improve public understanding of global warming issues and to create a more receptive atmosphere for policy action is for scientists to repeatedly, patiently, and strategically present accurate, credible information to the media and policymakers. UCS's Sound Science Initiative is doing just that.
Part of what scientists must do is to explain why it is unrealistic and unnecessary to expect total scientific certainty before taking appropriate action to address the threat of global warming. As climatologist Stephen Schneider notes,
"I'm not 99 percent sure, but I am 90 percent sure [that the climate is changing]. Why do we need 99 percent certainty when nothing else is that certain? If there were only a 5 percent chance the chef slipped some poison in your dessert, would you eat it?"
In the IPCC's latest assessment report (2007), the scientists drew some very strong conclusions about the present reality of climate change. The Panel concluded, for example, that human-induced warming over recent decades is already affecting many physical and biological processes on every continent. Nearly 90 percent of the 29,000 observational data series examined revealed changes consistent with the expected response to global warming, and the observed physical and biological responses have been greatest in the regions that warmed the most. Examples of observed changes in response to 20th century warming include
- Shrinking glaciers
- Thawing permafrost
- Earlier break-up of river and lake ice
- Lengthening of mid- to high-latitude growing seasons
- Poleward and altitudinal shifts of plant and animal ranges
- Declines of some animal and plant populations
- Earlier tree flowering, insect emergence and egg-laying in birds.
The IPCC's Fourth Assessment Report has made it clear that there are a variety of strategies available today that, if implemented quickly, can rein in global warming and avoid the most severe consequences. The impact of the more ambitious of these strategies on the world economy is expected to be a fraction of a percent reduction in the annual average growth rate of global gross domestic product (GDP).
We also need strategies to cope with those consequences of global warming that are already unavoidable due to past emissions. Adaptation strategies are necessary to supplement climate change mitigation efforts.
While IPCC reports are not policy-prescriptive, the analysis they provide is highly policy-relevant. IPCC reports are strong evidence that scientists' voices can make a difference in the public debate and in public policy to address this global problem.
