White House Shifts Its Focus on Climate
August 26, 2004
By ANDREW C. REVKIN
In a striking shift in the way the Bush administration has
portrayed the science of climate change, a new report to
Congress focuses on federal research indicating that
emissions of carbon dioxide and other heat-trapping gases
are the only likely explanation for global warming over the
last three decades.
In delivering the report to Congress yesterday, an
administration official, Dr. James R Mahoney, said it
reflected "the best possible scientific information" on
climate change. Previously, President Bush and other
officials had emphasized uncertainties in understanding the
causes and consequences of warming as a reason for
rejecting binding restrictions on heat-trapping gases.
The report is among those submitted regularly to Congress
as a summary of recent and planned federal research on
shifting global conditions of all sorts. It also says the
accumulating emissions pose newly identified risks to
farmers, citing studies showing that carbon dioxide
promotes the growth of invasive weeds far more than it
stimulates crops and that it reduces the nutritional value
of some rangeland grasses.
American and international panels of experts concluded as
early as 2001 that smokestack and tailpipe discharges of
heat-trapping gases were the most likely cause of recent
global warming. But the White House had disputed those
The last time the administration issued a document
suggesting that global warming had a human cause and posed
big risks was in June 2002, in a submission to the United
Nations under a climate treaty. President Bush distanced
himself from it, saying it was something "put out by the
That may be harder to do this time. The new report, online
at www.climatescience.gov, is accompanied by a letter
signed by Mr. Bush's secretaries of energy and commerce and
his science adviser.
The White House declined yesterday to explain the change in
emphasis, referring reporters to Dr. Mahoney, assistant
secretary of commerce for oceans and atmosphere and the
director of government climate research.
In an interview, he said the report was mainly an update on
the overall climate research program and was not intended
to be a conclusive "state of the science'' summary of the
administration's thinking. A series of 21 reports are
promised on particular issues in coming years, he said, and
the studies on climate models, agriculture and other
subjects mentioned in the new report are "significant but
Still, the report was disputed by some groups, aligned with
industry, that oppose restrictions on carbon dioxide
emissions and have attacked science pointing to dangerous
human-caused warming as flawed.
Myron Ebell of the libertarian Competitive Enterprise
Institute said the report was "another indication that the
administration continues to be incoherent in its global
At the same time, the report did not please environmental
groups, which have repeatedly criticized Mr. Bush for
opposing efforts to require restrictions on the gases
linked to global warming, though he has gradually come
around to the position that warming is at least partly
caused by emissions.
"The Bush administration on the one hand isn't doing
anything about the problem, but on the other hand can't
deny the growing science behind global warming," said
Jeremy Symons of the National Wildlife Federation.
The studies in the report that point to a human cause for
recent warming all involved supercomputer simulations of
climate, which have increased in power over the last
The latest analysis, done at the National Center for
Atmospheric Research in Boulder, Colo., found that natural
shifts in the output of the sun and other factors were
responsible for the warming from 1900 to 1950, but could
not explain the sharp and continuing rise since 1970.
The report's section on agriculture focused on several
studies in which fields and grasslands were exposed to
doubled concentrations of carbon dioxide, with growth
patterns in plants shifting in ways that could harm yields.
In such conditions, it said, plots of shortgrass prairie in
northeastern Colorado contained less of the nutrient
nitrogen, and their grasses were less digestible than those
that grew with no extra carbon dioxide.
"In another experiment, increased CO2 stimulated the growth
of five of the most important species of invasive weeds,
more than any other plant species yet studied," the report
said. "This suggests that some weeds could become bigger
problems as CO2 increases."