Coal produces about 30% of US greenhouse gas emissions
The US state of Georgia has blocked construction of a new coal-fired power station because of concerns over its carbon dioxide emissions.
Environmentalists welcomed the news, and predict the decision will lead to reconsideration of many coal power plants under development in the US.
The judge cited a decision by the Supreme Court last year which issued a ruling recognising CO2 as a pollutant.
This is the first court judgement on an industrial plant based on that ruling.
Earlier this year, Georgia's Department of Natural Resources issued a permit allowing the Dynegy company to begin construction of its Longleaf coal plant.
But Fulton County Superior Court Judge Thelma Wyatt Cummings Moore has now halted construction of the 1,200 megawatt facility, ruling that the permit should have set limits on carbon emissions.
Coal plants across the country will be forced to live up to their clean coal rhetoric Bruce Nilles, Sierra Club
She based her decision on the 2007 federal Supreme Court judgement that ended several years of legal disgreements by ruling that carbon dioxide, the most important gas in the human-induced greenhouse effect, should be regarded as a pollutant under the US Clean Air Act.
Dynegy is the largest coal plant developer in the US, with more proposed new coal plants than any other company.
Major emissions
Environmentalists believe the decision will influence the building of power plants across the US.
Bruce Nilles, director of the Sierra Club, said the decision marked a change in global warming regulation in the US because coal plants would now have to take into account their CO2 impacts.
"Coal-fired power plants emit more than 30% of our nation's global warming pollution," he said.
"Thanks to this decision, coal plants across the country will be forced to live up to their clean coal rhetoric."
Coal is a particular target for environmental campaigners
The Fulton County court is the first to apply a ruling of this nature under the Clean Air Act, although last year, Kansas governor Kathleen Sebelius rejected a new coal plant on the grounds that global warming is a threat to public health and agriculture.
The developers of the $2 billion Longleaf plant plan to appeal to a state appeals court, and say they are still committed to the project.
Scott Segal, director of the Electric Reliability Coordinating Council, a Washington based industry organisation, said the judges assumptions "do not square with the facts or the law".
"The Georgia state court has written an opinion fully in uncharted territory," he told the Reuters news agency.
More coal plants are now under construction in the US than at any time in the last 20 years.
The Sierra Club anticipates that the ruling will accelerate moves to produce a strong federal bill to protect the climate.
