President George W. Bush signed a landmark bill Tuesday, marking a major change in U.S. energy policy designed to decrease Americans’ oil thirst and fight global warming.

The bill will sharply raise mileage standards for automakers for the first time in three decades and require more use of alternative fuels such as ethanol. It will also increase efficiency requirements for appliances and allow the establishment of regional efficiency standards for HVAC equipment.

At the signing ceremony, the president, flanked by Democratic leaders of the U.S. House and Senate, hailed the bill. “Taken together, all these measures will help us improve our environment,” Bush said. “It is estimated that these initiatives could reduce projected CO2 (carbon dioxide) emissions by billions of metric tons.”

Controversial bill provisions dealing with the repeal of tax breaks for oil and natural gas producers and renewable energy mandates for electricity production were dropped to ensure passage and the president’s signature.

Still in the final bill, however, were rules allowing the U.S. Energy Department to create regional energy-efficiency requirements for furnaces, heat pumps and air conditioners.

Currently, such equipment must conform to one nationwide minimum efficiency standard.

The provision split the HVAC community, with groups such as the Air Conditioning Contractors of America, Plumbing-Heating-Cooling Contractors, and the Heating, Refrigerating and Airconditioning Distributors International opposing the bill and the Air-Conditioning and Refrigeration Institute, which represents equipment makers, supporting it.

“The bill provides incentives and standards for both commercial and residential users to upgrade their heating and cooling equipment to more efficient choices with the goal of reducing energy consumption,” said Stephen R. Yurek, ARI president. “We commend Congress for passing it and President Bush for signing it into law.”

ARI officials note that before regional standards can be established, the Department of Energy has to prove they will save energy, be technologically feasible and not burden the industry.

“We hope Americans will embrace this new law and take advantage of the array of energy-efficient heating, cooling and commercial refrigeration equipment manufactured by our members,” Yurek said.

Members of the ACCA and HARDI, however, weren't buying it.

“This unprecedented ‘regionalization’ strategy will drive up equipment and installation costs for every homeowner,” said Charlie McCrudden, government affairs director for the ACCA.

HARDI Vice President Talbot Gee questioned whether the homeowners would see their overall energy costs decline because of the bill.

“I doubt that consumers will be thinking about the benefits of blended fuel in their cars when their air conditioners need to be replaced at the peak of summer and they can’t afford replacement equipment,” Gee said.