U.S. environmental regulators quietly published a draft study on Thursday that linked global warming to higher levels of smog that could harm human health, a report green groups said stood in contrast to the Bush Administration's slow movement on climate change.
The draft report published by the Environmental Protection Agency in the Federal Register said, "Climate change has the potential to produce significant increases in near-surface (ozone) concentrations in many areas of the U.S."
It said parts of the Mid-Atlantic, Northeast and lower Midwest show some increases in ozone in study simulations, and the seasons in which ozone is a problem could last longer as a result of higher temperatures.
Ozone smog endangers the health of people, especially the young, old and those with respiratory problems.
"This report addresses the fundamental question that global warming is a threat to public health," said Frank O'Donnell, president of the nonprofit group Clean Air Watch.
"It stands in sharp contrast to the Bush administration's foot-dragging political approach," on regulating man-made emissions of carbon dioxide and other gases blamed for warming the planet, he said.
A White House spokesman did not immediately respond to a request for an interview about the draft study.
Earlier this week, leading Senate Democrat Barbara Boxer accused the Bush Administration of a "cover-up" aimed at stopping the EPA from tackling greenhouse emissions.
Jason Burnett, the agency's former associate deputy administrator who resigned last month, accused Vice President Dick Cheney's office of pressuring the EPA to remove references to the human health consequences of climate change in testimony for delivery to Boxer's Environment and Public Works Committee last year.
The EPA has been under pressure since a landmark 2007 ruling by the Supreme Court that it must reconsider its refusal to regulate carbon dioxide emissions from new cars and trucks.
In March, it started the long process of writing regulations for emissions from both cars and stationary sources like power plants. EPA administrator Stephen Johnson is slated to hold a press conference on Friday on proposed rulemaking on greenhouse gases.
The EPA said Thursday's draft study does not represent agency policy "at this stage" and announced a 45-day public comment period on the draft ending on August 25.
