The summit's host, German Chancellor Angela Merkel is preparing for divisive negotiations on Thursday and Friday. Merkel, who currently holds the rotating EU presidency, has made energy policy a top priority. A number of ambitious proposals would position Europe as the global frontrunner in the fight against radical climate change.

While EU members have endorsed some of the proposals put forward by the German presidency, others have been met with determined resistance. At a meeting of European foreign ministers in Brussels on Monday, member states agreed to cut carbon dioxide emissions to 20 percent below 1990-levels by 2020. This target will likely be legally binding.

But German Foreign Minister Frank-Walter Steinmeier, who chaired the meeting with his European colleagues, said that "no breakthrough was possible" on the question of how much energy should be supplied from renewable and nuclear sources. "It will have to be debated at the European Council" later this week, he said.

50-50 split on the nuclear issue

Diplomats in Brussels said the 27-member European Union was split squarely down the middle. Germany, Sweden, Denmark, Britain, Spain and Italy have voiced strong support for a binding target of 20 percent of energy consumption from renewable sources by 2020.

On the other side, France has been the most vocal critic of the renewable energy targets, but may accept a binding agreement if nuclear energy is included in the mix. Poland, Finland, Luxembourg and Bulgaria also expressed doubts about the binding nature of the targets, warning against setting unreachable goals on member states.

"That's going to be the key issue" at Thursday's summit, Steinmeier said.

Germany has one of Europe's leading renewable energy industries, with an extensive network of wind turbines, solar and hydro-electric plants. The German government plans to phase out its nuclear reactors. Meanwhile, France relies heavily on nuclear energy, and is worried that the renewable targets could jeopardize its national energy mix.

"Renewable energies are important, they must be developed and France is well placed to do that, but it is not enough to achieve our own goals," French European Affairs Minister Catherine Colonna told the AFP news agency.

Atomic energy reactors emit very little carbon dioxide gas, but pose other environmental problems. Uranium fuel rods, necessary for nuclear energy production, are costly and hazardous to dispose of when spent, and there is always a small chance of a nuclear meltdown. In many EU countries, therefore, public opinion is strongly anti-nuclear.

Europe leading the world

Europe -- and Germany in particular -- has expressed its desire to put in place the world's most progressive energy policies, leading the way for other nations in the global effort to mitigate the effects of global warming.

European member states have agreed on a 10 percent increase in bio-fuels – such as ethanol gained from corn crops – over the next three years. And Germany has already achieved close to a 20 percent national reduction of its CO2 levels compared to 1990.

But at times, the EU has struggled to agree on a common approach, as member states tend to put national interests first. According to German Chancellor Merkel, this is all about to change.

"So far, European nations have made their own energy policy," she told the German daily Süddeutsche Zeitung on Sunday, but "all that is now up for negotiation" at the upcoming EU summit.

Meanwhile, other industrialized nations are falling behind what climate experts say is a necessary global reduction of greenhouse gases. In the United States, a Bush administration report to the United Nations estimates that instead of reducing US emissions by 2020, they will actually rise to 20 percent above 2000 levels. A copy of the document, whose publication has been delayed for over a year, was obtained by the Associated Press on Monday.

And in Britain, a recent independent scientific audit of British climate change policies described the government's projections as "overly optimistic."

The German presidency is an opportunity for Chancellor Merkel to get other industrialized nations, as well as developing countries, to make solid commitments for a cleaner future. But the divisions in the run-up to this week's EU summit are only a taste of the difficulties that lie ahead of Merkel's ambitious green crusade.