In its new "Dirty Thirty" ranking of power station pollution in the European Union, the WWF (World Wildlife Fund) said Greece's Agios Dimitrios plant was the worst, followed closely by Frimmersdorf in Germany and Abono in Spain.

The WWF study ranked plants across the EU's 25 member states according to their efficiency -- a calculation based on the number of grams of carbon dioxide (CO2) emitted per kilowatt hour of electricity generated. Carbon dioxide, a byproduct which results from the burning of fossil fuels such as oil, gas and coal, is the primary component of greenhouse gases that trap the sun's heat and cause the Earth's temperature to rise.

German plants among worst offenders

Germany is home to five of the survey's ten dirtiest plants--four of which are run by the country's giant power company RWE. RWE was labeled as the biggest CO2 producer in the European power sector, according to the WWF.

"German power plants are Europe's top 'climate-killers,'" said WWF expert Regine Günther. "The summer of 2005, with the floods, droughts and heat-waves is just a taste of what can happen if CO2 emissions are not drastically reduced. Energy providers need to stop playing politics and finally start taking protective measures."

The WWF ranking showed that RWE plants in Frimmersdorf, Weisweiler, Neurath and Niederraussen ranked second, sixth, seventh and tenth respectively. Additionally, a plant in Jänschwalde operated by the Swedish power company Vattenfall ranked fifth. Of the dirtiest power plants, 27 out of the 30 are coal-powered facilities.

Energy sector target of renovation

"The power sector is responsible for 37 percent of all man-made CO2," said Imogen Zethoven, head of the WWF's power campaign.

"Coal-fired power stations rank dirtiest, because they use the most CO2-intense fuel. To switch off global warming we have to replace them with cleaner alternatives, such as gas and renewables," she said, referring to solar, wind and water power.

Over the next two decades, many of the "Dirty Thirty" are set to be decommissioned, noted the WWF, calling this a "historic window of opportunity to cut CO2 pollution." Replacing the outdated facilities with new coal power stations would result in a 13.5 percent cut in their total CO2 emissions by 2030, it said.

Likewise, a shift to gas would slash CO2 emissions by 47.8 percent, while replacing them with renewable energy sources would result in a 73.4 percent cut.

Europe just part of the equation

Under the Kyoto Protocol, industrial countries that have ratified the treaty are required to trim pollution of carbon gases by a deadline of 2012 as compared with a 1990 benchmark.

Many scientists still feel however that this effort falls far short of what is needed to avoid a rapid change in climate which could lead to a major global environmental crisis. After all, the UN plan does not include the world's top polluter, the United States, or developing countries such as China and India, where fast economic growth is driving up emissions.