In a stark shift for the Bush administration, the United States has sent a climate report to the United Nations detailing specific and far-reaching effects that it says global warming will inflict on the American environment.
In the report, the administration for the first time mostly blames human actions for recent global warming. It says the main culprit is the burning of fossil fuels that send heat-trapping greenhouse gases into the atmosphere.
But while the report says the United States will be substantially changed in the next few decades "very likely" seeing the disruption of snow-fed water supplies, more stifling heat waves and the permanent disappearance of Rocky Mountain meadows and coastal marshes, for example it does not propose any major shift in the administration's policy on greenhouse gases.
It recommends adapting to inevitable changes. It does not recommend making rapid reductions in greenhouse gases to limit warming, the approach favored by many environmental groups and countries that have accepted the Kyoto Protocol, a climate treaty written in the Clinton administration that was rejected by Mr. Bush.
The new document, "U.S. Climate Action Report 2002," strongly concludes that no matter what is done to cut emissions in the future, nothing can be done about the environmental consequences of several decades' worth of carbon dioxide and other heat-trapping gases already in the atmosphere.
Its emphasis on adapting to the inevitable fits in neatly with the climate plan Mr. Bush announced in February. He called for voluntary measures that would allow gas emissions to continue to rise, with the goal of slowing the rate of growth.
Yet the new report's predictions present a sharp contrast to previous statements on climate change by the administration, which has always spoken in generalities and emphasized the need for much more research to resolve scientific questions.
The report, in fact, puts a substantial distance between the administration and companies that produce or, like automakers, depend on fossil fuels. Many companies and trade groups have continued to run publicity and lobbying campaigns questioning the validity of the science pointing to damaging results of global warming.
The distancing could be an effort to rebuild Mr. Bush's environmental credentials after a bruising stretch of defeats on stances that favor energy production over conservation, notably the failure to win a Senate vote opening the Arctic National Wildlife Refuge to exploratory oil drilling.
But the report has alienated environmentalists, too. Late last week, after it was posted on the Web site of the Environmental Protection Agency, private environmental groups pounced on it, saying it pointed to a jarring disconnect between the administration's findings on the climate problem and its proposed solutions.
"The Bush administration now admits that global warming will change America's most unique wild places and wildlife forever," said Mark Van Putten, the president of the National Wildlife Federation, a private environmental group. "How can it acknowledge global warming is a disaster in the making and then refuse to help solve the problem, especially when solutions are so clear?"
Scott McClellan, a White House spokesman, said, "It is important to move forward on the president's strategies for addressing the challenge of climate change, and that's what we're continuing to do."
Many companies and trade groups had sought last year to tone down parts of the report, the third prepared by the United States under the requirements of a 1992 climate treaty but the first under President Bush.
For the most part, the document does not reflect industry's wishes, which were conveyed in letters during a period of public comment on a draft last year.
The report emphasizes that global warming carries potential benefits for the nation, including increased agricultural and forest growth from longer growing seasons, and from more rainfall and carbon dioxide for photosynthesis.
But it says environmental havoc is coming as well. "Some of the goods and services lost through the disappearance or fragmentation of natural ecosystems are likely to be costly or impossible to replace," the report says.
The report also warns of the substantial disruption of snow-fed water supplies, the loss of coastal and mountain ecosystems and more frequent heat waves. "A few ecosystems, such as alpine meadows in the Rocky Mountains and some barrier islands, are likely to disappear entirely in some areas," it says. "Other ecosystems, such as Southeastern forests, are likely to experience major species shifts or break up into a mosaic of grasslands, woodlands and forests."
Despite arguments by oil industry groups that the evidence is not yet clear, the report unambiguously states that humans are the likely cause of most of the recent warming. Phrases were adopted wholesale from a National Academy of Sciences climate study, which was requested last spring by the White House and concluded that the warming was a serious problem.
A government official familiar with the new report said that it had been under review at the White House from January until mid-April, but that few substantive changes were made.
Without a news release or announcement, the new report was shipped last week to the United Nations offices that administer the treaty and posted on the Web (www.epa .gov/globalwarming/publications /car/).
A senior administration official involved in climate policy played down the significance of the report, explaining that policies on emissions or international treaties would not change as a result.
Global warming has become a significant, if second-tier, political issue recently, particularly since James M. Jeffords, the Vermont independent, became chairman of the Senate Environment and Public Works Committee last year. Mr. Jeffords has criticized the president's policy.
The new report is the latest in a series on greenhouse gases, climate research, energy policies and related matters that are required of signatories to the United Nations Framework Convention on Climate Change, which was signed by Mr. Bush's father and ratified by the Senate.
The convention lacks binding obligations to reduce gas emissions like those in the Kyoto Protocol.
Mr. Bush and administration officials had previously been careful to avoid specifics and couch their views on coming climate shifts with substantial caveats. The president and his aides often described climate change as a "serious issue," but rarely as a serious problem.
The report contains some caveats of its own, but states that the warming trend has been under way for several decades and is likely to continue.
"Because of the momentum in the climate system and natural climate variability, adapting to a changing climate is inevitable," the report says. "The question is whether we adapt poorly or well."
Several industry groups said the qualifications in parts of the report were welcome, but added that the overall message was still more dire than the facts justified and would confuse policy makers.
Dr. Russell O. Jones, a senior economist for the American Petroleum Institute who wrote a letter to the Environmental Protection Agency a year ago seeking to purge projections of specific environmental impacts from the report, said it was "frustrating" to see that they remained.
"Adding the caveats is useful, but the results are still as meaningless," Dr. Jones said.
Copyright 2002 The New York Times Company