After months of discussion, the European Union's 28 member states have overcome their differences and agreed to cut greenhouse gas emissions by 40%, compared with 1990 levels, up to 2030.

Signed in Brussels on Oct. 23, the agreement also foresees increasing the share of renewable energy in the overall energy mix to 27% and improving energy efficiency by the same margin.

While the first target is binding and subject to enforcement throughout the EU, the second is not binding. Europe is already on target to cut CO2 emissions by 20% up to 2020, but up to now only five countries had climate targets beyond that date.

Finding a compromise was difficult, as individual member states have taken different paths in their approach to emissions control. Poland, which depends heavily on coal, lobbied for less ambitious goals. The UK, which is embracing shale gas, opposed nationally binding targets for renewables.

Depending on the commentator's position, the EU vote was hailed a "landmark deal" or a bad compromise.

In its favour, some noted that the accord makes the EU the first major global emitter to put its position on the table ahead of the UN climate meeting to be held in Paris at the end of 2015.

German chancellor Angela Merkel said the emissions target guarantees that Europe will be "an important player in future binding commitments of an international climate agreement."

EU Commission president, Hermann van Rompuy, called the deal "the world's most ambitious, cost effective" climate policy, and EU Commissioner for Climate Action, Connie Hedegaard, praised the leaders for "getting their act together on this pressing climate challenge."

Greenpeace, by contrast, called the climate package "very modest," and the European Environment Bureau said it was "desperately ineffective."

Environment groups contend that for Europe to make its proportionate contribution to curbing global warming, emissions would need to be reduced by 55%, the share of renewables to 45% and energy efficiency by 40% up to 2030.

With its latest "timid" move, the EU cannot possibly meet its self-set target of cutting emissions by 80% up to 2050, some commentators on the "green" side of the discussion said. Others said Europe had caved into industrial interests.