Wednesday, July 30, 2008

Climate Experts Tussle Over Details. Public Gets Whiplash.

When science is testing new ideas, the result is often a two-papers-forward-one-paper-back intellectual tussle among competing research teams. When the work touches on issues that worry the public, affect the economy or polarize politics, the news media and advocates of all stripes dive in. Under nonstop scrutiny, conflicting findings can make news coverage veer from one extreme to another, resulting in a kind of journalistic whiplash for the public.

This has been true for decades in health coverage. But lately the phenomenon has been glaringly apparent on the global warming beat.

Discordant findings have come in quick succession. How fast is Greenland shedding ice? Did human-caused warming wipe out frogs in the American tropics? Has warming strengthened hurricanes? Have the oceans stopped warming? These questions endure even as the basic theory of a rising human influence on climate has steadily solidified: accumulating greenhouse gases will warm the world, erode ice sheets, raise seas and have big impacts on biology and human affairs.

Scientists see persistent disputes as the normal stuttering journey toward improved understanding of how the world works. But many fear that the herky-jerky trajectory is distracting the public from the undisputed basics and blocking change. “One of the things that troubles me most is that the rapid-fire publication of unsettled results in highly visible venues creates the impression that the scientific community has no idea what’s going on,” said W. Tad Pfeffer, an expert on Greenland’s ice sheets at the University of Colorado.

“Each new paper negates or repudiates something emphatically asserted in a previous paper,” Dr. Pfeffer said. “The public is obviously picking up on this not as an evolution of objective scientific understanding but as a proliferation of contradictory opinions.”

Several experts on the media and risk said that one result could be public disengagement with the climate issue just as experts are saying ever more forcefully that sustained attention and action are needed to limit the worst risks. Recent polls in the United States and Britain show that the public remains substantially divided and confused over what is happening and what to do. Some environmentalists have blamed energy-dependent industries and the news media for stalemates on climate policy, arguing that they perpetuate a false sense of uncertainty about the basic problem.

But scientists themselves sometimes fail to carefully discriminate between what is well understood and what remains uncertain, said Kimberly Thompson, an associate professor of risk analysis and decision science at Harvard. And, Dr. Thompson said, the flow of scientific findings from laboratory (or glacier) to journal to news report is fraught with “reinforcing loops” that can amplify small distortions.

For example, she said, after scientists learn that accurate, but nuanced, statements are often left out of news accounts, they may pre-emptively oversimplify their description of some complex finding. Better, but more difficult, Dr. Thompson said, would be to work with the reporter to characterize the weight of evidence behind the new advance and seek to place it in context.

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