WASHINGTON — President Bush called for a halt Wednesday in the growth of greenhouse gases by 2025, acknowledging the need to head off serious climate change.

The plan came under fire immediately from environmentalists and congressional Democrats who favor mandatory emission cuts, a position also held by all three presidential contenders.

Bush in a Rose Garden address for the first time set a specific target date for U.S. climate pollution reductions and said he was ready to commit to a binding international agreement on long-term reductions as long as other countries such as China do the same.

"There is a wrong way and a right way to approach reducing greenhouse gas emissions," Bush said, making clear that he opposes a Senate measure that would impose mandatory limits on greenhouse gases beginning in five years, followed by annual reductions.

"Bad legislation would impose tremendous costs on our economy and American families without accomplishing the important climate change goals we share," the president said.

He said he envisions a "comprehensive blend of market incentives and regulations" that would encourage clean and efficient energy technologies. And he singled out the electric utility industry, saying power plants need to stabilize carbon dioxide pollution within 15 years and reduce them after that.

While characterized by the White House as a fresh strategy to attack climate change, the president gave no new proposals for achieving these pollution reductions.

He cited, instead, measures already enacted such as a 40 percent increase in auto fuel economy, a requirement for a huge increase in use of ethanol and other biofuels, and some efficiency standards, as well as a push for developing clean energy technologies.

Environmentalists said the Energy Department's own forecasts have shown that even with those advances — encompassed in energy legislation approved last year — U.S. carbon dioxide emissions are expected to increase by about 10 percent by 2025.

"If this is President Bush's idea of 20/20 vision he needs to get his eyes checked," said Sen. John Kerry, D-Mass., calling the new White House climate initiative "late, insufficient and insincere."

Rep. Edward Markey, D-Mass., said Bush's remarks showed that "he has no intention of cooperating" to get climate legislation passed this year. "He's basically saying take two aspirins and call President Obama, Clinton or McCain next January," Markey told reporters.

All three presidential contenders are supporters of mandatory limits — a so-called cap-and-trade system — to reduce climate changing pollution, mainly carbon dioxide from the burning of fossil fuels. Sen. John McCain, the presumptive GOP nominee, has been a co-sponsor of mandatory emissions cap legislation. Democratic candidates Sens. Barack Obama and Hillary Rodham Clinton both have said they would make binding emissions reduction requirements a top priority.

Some conservative House Republicans have expressed privately to the White House concern about Bush's call for a timetable for emission reductions, while other congressional Republicans said they welcomed the president becoming more engaged in the issue.

"The president has articulated a progressive vision for a comprehensive solution to climate change," said Sen. George Voinovich, R-Ohio, who has voiced concern about the economic cost of the Senate climate bill.

Rep. James Sensenbrenner, R-Wis., who like the president has been critical of mandatory caps on greenhouse emissions, said, "It is clear ... that we both share important principles that must be part of any policy addressing climate change, including support of technology."

Still, Senate Democrats and environmentalists said the president's plan would allow continued growth of greenhouse gases for nearly two decades, during which the government estimates heat-trapping emissions from U.S. electric power plants alone are expected to grow by 16 percent.

Sen. Barbara Boxer, D-Calif., chairwoman of the Senate Energy and Environment Committee, called Bush's new climate strategy "worse than doing nothing" and would "have America stand by while greenhouse gases reach dangerous levels."

A climate bill expected to be taken up by the Senate in June would call for a 19 percent reduction in greenhouse gases by 2025 and about a 70 percent reduction by mid-century from power plants, transportation and industrial sources.

Bush called such a requirement "unrealistic" and economically damaging, but indicated that he would like to see some congressional action on climate this year to avert what aides have characterized as a "train wreck" of regulations under existing laws such as the Clean Air Act and Endangered Species Act.

These laws "were never meant to regulate global climate change," said Bush, and would "make the federal government act like a local planning and zoning board."

A year ago, the Supreme Court declared that carbon dioxide is a pollutant under the Clean Air Act and directed the Environmental Protection Agency to determine whether CO2 is endangering public health or welfare. If so, the court said, the EPA must regulate CO2 emissions.

At the same time, the Interior Department has been told by another court to decide whether the polar bear should be brought under the protection of the Endangered Species Act because of disappearing sea ice — a phenomenon blamed by scientists on global warming.

White House: www.whitehouse.gov