Among scientists in two fields that focus closely on climate—geophysics and meteorology—few now doubt that the planet is warming or that human activity is to blame, even though views diverge on the dangers posed, says a new survey released by the Statistical Assessment Service at George Mason University.
Of the 489 Earth and atmospheric scientists surveyed by Harris Interactive, 97 percent said that global temperatures have increased during the past 100 years, and 74 percent agreed that "currently available scientific evidence substantiates the occurrence of human-induced greenhouse warming." The findings mark a significant increase in concern over climate change since 1991, when a Gallup survey of the same universe of scientists showed only 60 percent agreed that temperatures were up and 41 percent believed that evidence pointed to human activity as the cause.
The scientists were about evenly divided on whether they thought the effects of global climate change over the next 50 to 100 years were likely to be near catastrophic (41 percent) or moderately dangerous (44 percent). About 13 percent saw relatively little danger. About 56 percent of the scientists said that global climate change was a mature science, while 39 percent termed it an emerging science.
"There is still more debate among scientists than I expected," said Robert Lichter, STATS president, pointing to these last results. "It's not surprising that there's a long-term trend toward consensus. But I think in the media you don't always see the continuing debate beneath the headlines. Scientists are not aligned with the yes party and the no party. They are still searching. They believe human-induced global warming is a problem but that there are many things we need to know."
Only 41 percent of the geophysicists and meteorologists in this survey said they were directly involved in any aspect of global climate science. One of the nation's leading climate scientists, Richard Somerville, professor emeritus at the Scripps Institution of Oceanography at the University of California-San Diego, says there is a readily available source for the consensus view of scientists who do focus on climate: the reports of the Nobel Prize-winning Intergovernmental Panel on Climate Change. Somerville was a lead coordinating author on the most recent IPCC report, which concluded that warming was "unequivocal" and most of it was "very likely due" to increased greenhouse gas concentrations caused by human activity. "Are people agreed there are other things we need to know? Yes," says Somerville. "But the fact that the science is incomplete is not a reason for postponing action. When your physician says you need to cut back on eating or drinking and exercise more, you don't answer by saying the medical science is incomplete or ask him to predict what day your heart attack will occur."
Harris Interactive, conducting the poll for STATS, sought a random sample of scientists who were members of either the American Meteorological Society or the American Geophysical Union who also were listed in the current edition of American Men and Women of Science. (That method of sampling excluded TV meteorologists who were not scientists, says Lichter.) Although scientists in many other fields study the effects of global warming—ecologists and agronomists, for example—Lichter said STATS sought those most concerned with climate issues most of the time. However, 72 percent of those polled said they had "never" or "almost never" published articles or books on climate change. Lichter said the survey sought to replicate the universe polled by Gallup in 1991 and repeated several of the Gallup questions verbatim in order to track the change in opinion over time.
Funding for the survey came from the Randolph Foundation. STATS describes itself as a nonpartisan nonprofit that seeks to improve public understanding of science and scientific data. It has been frequently critical of media coverage of science.
About 65 percent of those surveyed said television news was "not very" or "not at all" reliable as a source of information on global climate change. In contrast, about 65 percent found the Al Gore documentary An Inconvenient Truth either "somewhat" or "very" reliable. There was not much faith in local newspaper coverage (about 58 percent ranking it unreliable), but coverage of climate by national newspapers like the New York Times and the Wall Street Journal was viewed as reliable by 67 percent of those surveyed.