Persuading the European Union as a whole to accept an increase in its target for cutting carbon emissions to 30 percent by 2020 would be politically very difficult, Danish Climate and Energy Minister Martin Lidegaard said on Tuesday. Denmark takes over the rotating EU presidency at the start of next year and is expected to promote a green energy agenda, in contrast to the incumbent Poland which has been viewed as an obstacle to a more ambitious climate agenda.

"I have not given up," Lidegaard told Reuters on the sidelines of a panel discussion. "But I'm looking at the political climate and thinking it's going to be hard to achieve 30 percent."

Poland's six-month presidency got off to a bad start as far as the environmental lobby was concerned after it blocked an attempt by EU ministers to introduce a 25 percent target for carbon reduction compared with the current goal of a 20 percent cut by 2020.

The 20 percent target is binding, as is another goal to increase the share of renewable energy in the mix to 20 percent, while a third target to improve efficiency by 20 percent is not binding.

Climate Commissioner Connie Hedegaard has said the 25 percent could be achieved simply by meeting the efficiency target and did not amount to a brand new goal.

As it stands, only about a 9 percent improvement in efficiency is likely to be made, Hedegaard said at the panel debate on Tuesday.

Lidegaard said the Danish presidency would prioritize legislation on energy efficiency as well as road maps on the climate and on energy, which aim to establish milestones toward a greener and more intelligent energy network beyond the binding 2020 targets.

A leader in wind energy, Denmark has one of the most ambitious sets of targets in the world for shifting from fossil fuels to carbon-free energy.

Scientists have said an 80-95 percent cut in carbon emissions is needed by the middle of the century to stave off the worst effects of global warming.

Ahead of a climate summit in Durban, South Africa, later this month, the European Union Environment Council in October adopted a set of conclusions in which it reaffirmed a conditional offer to move to a 30 percent cut in carbon emissions by 2020 compared with 1990.

The conditions attached included that other developed countries commit to comparable reductions.