EU heads of government are meeting in Brussels for their first summit of the year to discuss climate change.
One topic to be considered is the cutting of carbon emissions by 20% by 2020.
Disagreement is expected about how the cuts will be shared.
In pre-summit comments, German Chancellor Angela Merkel urged fellow-leaders to set the pace. She rejected concerns from business about the cost.
But Ms Merkel, who will chair the meeting, will have difficulty convincing up to a dozen countries to drop their resistance to binding targets.
She said binding targets would create the legal certainty that business leaders have demanded and argued it could be more costly to delay anti-pollution measures.
There jave been hints of a compromise, possibly allowing individual countries to manoeuvre on their take-up of renewables while setting a target for the EU as a whole.
But backers of tough action are wary of giving too much leeway.
