Although the E.U. has embraced renewable energy, efforts to implement more energy efficiency are moving much more slowly, as reflected in the cumbersome negotiations for the new European strategy to reduce emissions. On the one hand, countries agreed to a binding target of supplying 20 percent of Europe’s energy demand through renewable sources by 2020, up from the current 7 percent. But they couldn’t agree on which efficiency measures to implement, and instead left it to each country to decide how to meet its emission target.

If achieved, the goal could save the E.U. close to $180 billion annually, and enough G.H.G. emissions to meet its 2020 target, according to data from the E.U. Commission. While Europe’s overall share of renewable sources has increased, political unwillingness to enforce efficiency measures, coupled with growing energy demand, are the biggest challenges to meeting the emission reduction targets.

“Countries are not doing enough. Everybody is saying efficiency is important, but when it comes to implementing legislation, everything is a problem,” says Ferran Tarradellas, a spokesman for the E.U. Energy Commission. “The problem is politics. The reality is all that countries see is short-term investment, not the long-term results.”

Spain, for example, has achieved one of Europe’s most impressive increases in renewable energy installed capacity, but at the same time its emissions have increased by more than 50 percent since 1990. Economic growth accounts for most of the increase in emissions. But some analysts are hopeful that efficiency will help reduce the rate of growth of emissions in Spain, where both gas and electricity are still subsidized. “The trouble is that efficiency has to be implemented at member state level,” says Christian Egenhofer, a European energy policy and regulation expert in the Brussels-based Centre for European Policy Studies.

Less than half of the E.U. countries are implementing their efficiency plans, according to Egenhofer. As part of its carrot and stick strategy, the Commission will lay out a series of compulsory measures this year, geared particularly towards increased building insulation and improved transportation and household efficiency.

“There is very little progress in reducing domestic energy use,” Egenhofer said.

Car emissions, which are over 10 percent of the overall E.U. emissions, are a prime example. Although total E.U. emissions have decreased since 1990, due mostly to increased use of renewable energy, automotive emissions have jumped by nearly 30 percent.