By Barbara Lewis and Alastair Macdonald
The dialogue in Brussels dragged on into the early hours of Friday as Poland sought to preserve its coal industry and other states changed the draft on global warming to protect various economic interests, from nuclear plants and cross-border power lines to farmers whose livestock emit polluting methane. .
Finally, a general objective was agreed for the bloc of 28 countries to reduce its emissions by 2030 at least 40 percent over the levels set in the reference year of 1990.
The existing goal of a 20 percent reduction by 2020 has almost been met.
EU leaders called the 40 percent goal an ambitious sign, which the United States and China could emulate at a United Nations climate summit that France will host in December next year.
"Europe is setting an example," said French President Francois Hollande, who acknowledged that it had been a difficult compromise to obtain. "This is basically about survival," said summit director Herman Van Rompuy, president of the European Council.
But environmentalists had already complained that the deal could leave the EU short of the 80 percent reduction by 2015, which its own experts consider necessary to limit the rise in average global temperatures to two degrees Celsius.
Oxfam's Natalia Alonso applauded the 40 percent deal, but warned: "It falls too short of what the EU needs to contribute to the fight against climate change."
"Insufficient action like this by the world's richest countries places an even greater burden on the poorest people who are the most affected by climate change, but least responsible for causing the crisis," he added.