SAN FRANCISCO (Reuters) -- California Gov. Gray Davis on Friday announced plans to sue the U.S. Environmental Protection Agency over its recent decision that carbon dioxide should not be regulated under the federal Clean Air Act.

California, which has one of the worst pollution problems in the nation, recently adopted its own plan to combat global warming, partly through the strict regulation of carbon dioxide, which is emitted from cars, trucks, factories, power plants and several other sources.

Davis said the lawsuit was a preemptive move, designed to prevent the EPA would from blocking state efforts to regulate such emissions. "The EPA is wrong in its decision to relinquish federal control over greenhouse gases," Winston Hickox of the California Environmental Protection Agency said during a press conference to announce the planned lawsuit. "It delays addressing a serious health threat." A spokesman for Davis, who faces a recall election next Tuesday that could remove him from office, said the lawsuit would be filed "within days, not weeks."

The unpopular governor has long viewed protecting the environment as a cornerstone of his political agenda.

The debate over the regulation of carbon dioxide stems from the original language of the federal Clean Air Act, which was adopted 33 years ago, when lawmakers had less information about the causes of pollution and smog.

At the time, carbon dioxide was considered a benign gas, but has in more recent years been identified as a key source of pollution.

However the EPA has never adjusted its rules to address the latest science around the dangers of carbon dioxide.

During the administration of President Bill Clinton, it was silent on the matter, and last month it said it determined not to identify carbon dioxide as a source of pollution.