For E.U. Climate Meeting, Deep Divisions and High Stakes

BRUSSELS — The leaders of the 28 members of the European Union are set to meet here on Thursday to reassert their global leadership in climate protection, but they will first need to finesse deep divisions over how to generate and distribute energy.

Curbing the emissions that contribute to climate change has long been a popular cause in Europe, where policy makers frequently highlight how their industries and citizens emit fewer greenhouse gases like carbon dioxide than do the United States and other industrialized countries.

The two-day summit meeting this week is intended to strengthen and expand the region’s efforts to cut emissions, bolster renewable sources, improve energy efficiency and connect power markets separated by national borders.

But the long economic downturn in Europe has badly pinched spending on green-energy projects, and the advent of technologies to extract cheap shale gas — despite its uncertain prospects in Europe — has reduced the attractiveness of some renewable alternatives.

Adding to the complexity of the fight against emissions is the fallout from the disaster in Fukushima, Japan, where an earthquake and tsunami in 2011 led to multiple meltdowns at a nuclear power plant. This prompted questions about the future of nuclear energy even though nuclear facilities emit almost no gases linked to global warming. Germany, for one, has announced plans to shut all of its nuclear power plants by 2022.

Also hanging over the summit meeting is the standoff between the West and Russia over its annexation of Crimea in March and its involvement in fighting in Ukraine. For countries like Poland that border Russia, reliance on coal, which is highly polluting, is seen as preferable to switching to natural gas. Russia, a major supplier of gas, has been known to cut off supplies to countries during political disputes.

The Polish stance, which is also aimed at protecting jobs in its powerful mining industry, has put it at loggerheads with countries like Sweden and Germany that are seeking more ambitious targets for the use of renewable sources and to improve energy efficiency.

The British government vehemently opposes targets on energy efficiency because it fears that such limits would provide new arguments to opponents of Prime Minister David Cameron; some of them contend that he has surrendered sovereignty to Brussels and want Britain to leave the European Union.

France has been resisting demands to expand electricity connections across the Pyrenees that would transport large amounts of wind and solar energy from Spain and Portugal but and could reduce demand for French nuclear power.

The main item on the agenda at this week’s meeting is expected to be the so-called 2030 climate and energy package that was proposed in January by the European Commission, the executive arm of the European Union. The commission’s goal is to reduce greenhouse gas emissions by 80 percent to 95 percent below 1990 levels, by 2050.

On Thursday, the leaders are expected to discuss cutting emissions by 40 percent compared with the 1990 level, by 2030. Also under consideration are a target to generate 27 percent of energy in the bloc from renewable sources; improving energy efficiency by 30 percent; and increasing the number of so-called interconnectors between nations.

The European Union is on target to meet goals, set in 2008, to cut emissions by 20 percent by the end of this decade. But its members have not yet agreed on a course of action for after 2020. Reaching a deal this week would give the union bragging rights before a United Nations climate conference in Paris scheduled for late 2015, by making it the first major global emitter to put forward its position.

Polish leaders, however, have hinted that they may veto any agreement. And the German chancellor, Angela Merkel, has already warned that the summit meeting may end in deadlock, requiring further discussions. Analysts have warned that if a deal is reached, it will most likely be a messy compromise.

“The reality is that no true European solution seems possible in the energy sector at the moment,” said Georg Zachmann, an energy and climate specialist at Bruegel, a research organization based in Brussels. “Even if leaders agree on the proposed targets on renewables and efficiency this week, these can only be a weak form of coordination between countries with too many vested interests.”