President Bush this week called on the world's top emitters of greenhouse gases warming the world to set a "long-term goal" for reducing such pollution, but was vague on how to complete the task.

"By setting this goal, we acknowledge there is a problem," President Bush told representatives of 17 nations attending the Major Economies Meeting on Energy Security and Climate Change held in Washington, D.C., this week. "We must lead the world to produce fewer greenhouse gas emissions, and we must do it in a way that does not undermine economic growth or prevent nations from delivering greater prosperity for their people." The nations represented at the conference emit more than 80 percent of the globe's greenhouse gases.

Bush proposed that a conference be held by the summer to formally establish such a goal and pave the way for a "global consensus at the U.N. in 2009."

Strategies to meet the goal would vary by country and largely rely on advanced technology such as capturing the carbon dioxide spewed by coal-burning power plants; the Bush vision also foresees gasoline alternatives, nuclear power and an international clean technology fund to promote research into carbon-free energy sources. "The United States will do our part," Bush said. "We take this issue seriously."

Environmentalists hailed Bush's acknowledgement that climate change is a fact and largely man-made. But they say the proposal does not go nearly far enough. "He let the moment go by without making any change in his dogged refusal to put real limits on America's global warming pollution," says David Doniger, climate policy director at the Natural Resources Defense Council, a New York-based environmental group. "His opposition to capping and reducing our global warming pollution is the single biggest obstacle to making progress either here at home or with other countries."

Doniger notes that Bush has refused to sign on to a plan that calls for a 50 percent cut in carbon dioxide and other greenhouse gases by 2050 or to an effort to hold average temperatures from rising by more than 2 degrees Celsius (3.6 degrees Fahrenheit) above preindustrial levels, as have been proposed by other countries. "Real limits on pollution … would push private capital into clean energy projects," he says. "Instead, what he's proposing is an international government fund, with no money proposed—Treasury secretary Hank Paulson to pass the hat later. No matter what that comes up with, it will be smaller than what could be mobilized under carbon markets," where the right to emit greenhouse gases is traded among various sources.

Bush also came under fire from U.S. lawmakers, who slammed him for failing to propose or support any concrete plan for action. "The president is opposed to mandatory caps on greenhouse gases, opposing a mandatory 10- [mile-per-gallon] increase in cars and trucks, opposing a national renewable electricity standard, opposing state efforts to cut emissions from cars, and pushing for new sources of dangerous pollution from liquid coal," said Rep. Ed Markey (D–Mass.), chairman of the House Select Committee on Energy Independence and Global Warming, in a statement released after the speech. "For now, he still seems satisfied to reuse rhetoric and run out the clock on his administration without taking any measurable action to save the planet."

Markey's committee was created earlier this year by the Democratic-controlled House leadership to craft legislation to combat climate change. "At a certain point we will have a proposal," says committee spokesperson Eben Burnham-Snyder. But he says no timeline has been set. Meanwhile, a number of individual members of Congress have proposed their own potential laws.

The next international effort to come up with a global treaty to limit greenhouse gases is set to begin in Bali, Indonesia, on December 3. "Undoubtedly, there is a need for much deeper emission reductions from industrialized countries," said Secretary General Ban Ki-moon at the U.N. climate summit earlier this week. "Economic and social development cannot be sustainable unless we deal decisively with [climate change]."