The suit demands the Environmental Protection Agency regulate so-called greenhouse gases such as carbon dioxide, which the EPA under President George W. Bush has so far avoided, the groups said in a statement.

"The administration has insisted it's not their job to fight global warming," said David Bookbinder, attorney for Sierra Club, which was joined in the suit by Environmental Defense and the Natural Resources Defense Council.

"In fact they have both the legal and moral responsibility to tackle global warming pollution," he said.

The states of California, Connecticut, Maine, Massachusetts, New Mexico, Oregon, New York, Rhode Island, Vermont, Wisconsin are parties to the suit filed in US District Court in Washington, as were the District of Columbia and New York City.

EPA does not regulate carbon dioxide, the most plentiful of the greenhouse gases, because the agency, on direction from the White House, does not consider it pollution, the groups said.

While carbon dioxide is not toxic -- humans exhale it in large quantities -- it does contribute to the so-called greenhouse effect, where certain gases in the upper atmosphere allow sunlight in, without allowing the heat to escape Earth, not unlike a greenhouse.

The greenhouse effect has always been with us, but scientists say that as cars and power plants release increasing amounts of gases like carbon dioxide, temperatures rise faster and have already begun to disrupt weather patterns.

Related Links
-