Reports on global warming lag behind the science

When Rep. Bart Gordon gavels the House Science and Technology Committee to order Thursday morning, it will mark Congress's first hearings on the latest United Nations-sponsored report on global warming.

But even before several authors of the prestigious report discuss its findings, other authors say the process is too slow.

The problem: Climate science is moving too quickly for the ponderous reporting system to keep up, they argue. Besides receiving a written consensus once every six years, policymakers need some form of interim report to keep abreast of the science of global warming and make important decisions, they add.

"Some of us believe that going to some updates, especially as the science is changing very rapidly, might be a very good tack to take," says Linda Mearns, a scientist at the National Center for Atmospheric Research in Boulder, Colo., and one of 15 lead authors on the chapter dealing with projections of global warming's regional effects.

Updates could come from the UN-affiliated group itself, the Intergovernmental Panel on Climate Change (IPCC), or some other organization, such as the World Climate Research Program.

To be sure, many scientists involved in the laborious process look askance at having to wrestle with yet another report.

"Every six years is fine. Do you want me to start twitching" from the added pressure? quips Ronald Stouffer, a researcher at the federal Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, N.J., who has been deeply involved in the IPCC's four major science reports since 1990.

Pulling off a major, rigorously reviewed summary of climate science is a Herculean task.

While some critics hold that the report and its summary are the work of faceless bureaucrats, the main science report – more than 1,600 pages in its draft form – was compiled by 150 scientists as main authors, another 400 scientists as contributing authors, a team of review editors, and some 600 reviewers. The document went through two rounds of reviews. And unlike past efforts, review editors required chapter authors to respond to each responsible review comment.

Although governments review, suggest changes, and decide whether to accept the completed 21-page summary for policymakers, the scientists assembled in Paris last week had the final say over the report's wording, notes Keith Dixon, a researcher at the GFDL and another IPCC participant. If countries fail to accept the final product by consensus, the summary gets published anyway. At worst, the IPCC changes the report's billing, dropping the "for policymakers" from the title.

The process is a heavy draw on time and energy within the climate-science community. For example, scientists at GFDL devoted half of their supercomputer's time for a year running models for the latest report. It's a worthwhile task, Dr. Dixon says. Researchers who take part in the IPCC process do so as volunteers. But it comes at a cost. "The typical metrics that a lot of research scientists use to gauge their careers take a hit by doing this," he says. Individual research projects get postponed and journal articles don't get published.

Researchers who advocate some sort of interim update to the main reports say research results published too late to be included in this year's science assessment might have led to higher estimates for some of global warming's effects. For example, they cite work appearing throughout 2006 suggesting that Greenland's ice cap is losing mass faster than scientists expected or models projected. The melt would need to continue for at least 1,000 years for the ice cap to vanish, raising sea levels some 23 feet globally. But if the speedup in ice melt continues, estimates for sea-level rise this century would need to be revised upward – potentially affecting efforts to adapt to the changes.

Still, some scientists caution that tinkering with the process would be counterproductive. The three-year process of writing, reviewing, and achieving a consensus among the scientists is what makes the IPCC science report "a gold standard," notes Richard Somerville, a researcher at the Scripps Institution of Oceanography in La Jolla, Calif. Moreover, others suggest that more-frequent updates might give contrarians additional opportunities to push for a wait-and-see approach.

"The process needs to be what it is to ensure that it weathers criticism," says Vicki Arroyo, director of policy analysis for the Pew Center on Global Climate Change in Arlington, Va. "But something in the interim that at least allows you to give a sense of the most recent science would be helpful."