A few months into his presidency, Bill Clinton got burned on global warming.
He proposed a tax on fuels that produce carbon dioxide, the main "greenhouse gas" many scientists believe is the culprit behind climate change. But the "carbon tax" idea went nowhere - and that was even before Republicans took over Congress - and Mr. Clinton fell back on proposals relying largely on voluntary efforts.
Now, the White House once again is emphasizing what is becoming a profound environmental issue that could have universal impact. Meeting with industry leaders this week, Clinton cited "pretty clear evidence that the climate is changing" and called for "realistic but binding limits to emissions of greenhouse gases." The key word here was "binding," meaning that strict limits would have to be met.
The White House activity comes at a time when the prospect of global warming, while still a subject of considerable scientific and political debate, seems to be more of a certainty. And it follows a shift in position by some industry skeptics who now agree that steps should be taken to head off global warming.
British Petroleum has broken from its oil-producing colleagues to acknowledge the likely existence of global warming. And major insurance companies around the world (which must cover the cost of property damage when extreme weather events occur) have called for "early, substantial reductions in greenhouse gas emissions."
"The balance of evidence suggests that there is a discernible human influence on climate," says Jane Lubchenco, professor of zoology at Oregon State University and one of seven prominent scientists who recently briefed the president and Vice President Al Gore on the latest evidence that human activities are affecting climate patterns around the world.
The event (which featured three Nobel laureates) was seen by the White House as an opportunity to educate the public as well on a subject that can seem arcane and threatening.
Dr. Lubchenco cites as evidence increases in recorded temperatures, changes in sea levels, increases in the incidence of tropical diseases, and more instances of extreme weather events such as floods, hurricanes, and droughts.
"You can't say that this flood or this hurricane or this drought was caused by climate change," cautions Lubchenco, who recently finished up a term as president of the 144,000-member American Association for the Advancement of Science (AAAS). "What you can say is that we are seeing increases in the frequency of these things, and those increases are consistent with the predictions of the [computer] models."
This, in essence, is the same thing some 2,500 scientists on the United Nations Intergovernmental Panel on Climate Change (IPCC) have said in recent reports.
Skeptics say such assertions aren't supported by hard facts, and they warn that forcing sharp changes in such things as transportation, energy generation, and manufacturing at this point could hurt the economy.
Under United Nations auspices, representatives of developed and developing countries met recently in Bonn to lay the groundwork for a December summit of 160 nations in Kyoto, Japan. Delegates to the Kyoto meeting aim to conclude an agreement that would reduce greenhouse gas emissions well below current levels.
Gail McDonald, president of the Global Climate Coalition (an industry organization), warns that moving now on such an agreement "could have devastating impacts on our economy" and "may easily become the most economically devastating federal policy blunder of the decade."
Clinton, too, is sensitive to the economic part of the global warming equation.
In his meeting Monday with 10 chief executives of utility, oil, gas, steel, chemical, manufacturing, and financial services companies, the president said "we have to do it in a way that keeps our economy growing."
Advocacy groups such as the Union of Concerned Scientists and the Environmental Defense Fund have insisted all along that energy conservation and alternatives to carbon-emitting fuels could reduce the threat of global warming while maintaining a healthy economy. But now, some companies are aligning themselves with this way of thinking as well.
"It is a moment for change and for rethinking of corporate responsibility," British Petroleum chief executive John Browne said at a speech at Stanford University in May. While noting the "large elements of uncertainty about cause and effect," Mr. Browne acknowledged "an effective consensus among the world's leading scientists and serious and well-informed people outside the scientific community that there is a discernible human influence on the climate, and a link between the concentration of carbon dioxide and the increase in temperature."
In addition to environmental and economic concerns, some experts see global warming as a matter of national security. Paul Nitze, who negotiated arms-control agreements with the former Soviet Union during the Reagan administration, says nations must "address the looming threat to geopolitical stability posed by climate change."
"The question is no longer 'Is our climate changing?' but 'What can we do about it?' " he wrote in a recent column in The Washington Post.