Governments must act quickly to reduce emissions of greenhouse gases, the world's science academies said Tuesday.

The statement, jointly published by the national academies of science in several countries, came as British Prime Minister Tony Blair met with U.S. President George W. Bush in Washington, D.C.




Blair and other European leaders support mandatory limits on greenhouse gas emissions that scientists say contribute to global climate change.

The White House opposes mandatory limits, saying it would cost too much to the American economy. The U.S. administration favours using technology to reduce emissions.

"The current U.S. policy on climate change is misguided," said Lord May, president of the Royal Society. He added the policy ignores scientific evidence from the U.S. National Academy of Sciences.

After meeting with Blair, Bush called climate change "a serious long-term issue that needs to be dealt with," but the pair did not agree on a new way to tackle emissions.

The statement is published by the U.K. national academy of science, along with its counterparts in France, Russia, Germany, U.S., Japan, Italy and Canada.

Academies in Brazil, China and India, countries which are among the largest emitters of greenhouses gases in the developing world, also signed the statement.

The statement was also released ahead of the July G-8 summit of wealthy countries in Gleneagles, Scotland.

It calls on G-8 nations to find "cost-effective steps" immediately to "contribute to substantial and long-term reductions in net global greenhouse gas emissions."

Delaying action increases the risk of poor effects on the environment and will likely cost more, the statement said.

"It is clear that world leaders, including the G-8, can no longer use uncertainty about aspects of climate change as an excuse for not taking urgent action to cut greenhouse gas emissions."

Fighting global warming and contributing more aid to Africa top Blair's agenda for the G-8 summit.