* March EU summit to debate energy, environment goals
* Thirteen EU environment ministers calling for urgency
* Host of U.N. talks Poland not among them
* Poland says notion of EU leadership 'counterproductive'
BRUSSELS, Nov 8 (Reuters) - Once a clear environmental leader, the European Union is likely to set a more cautious tone for the global debate on a U.N. climate deal when it unveils a new chunk of green energy law early next year.
Warsaw talks starting on Monday assemble almost 200 nations to prepare for a U.N. global pact, to be sealed in 2015, by extracting new promises on emissions cuts.
The EU draft law should make the European Union the first major bloc to outline binding environment and energy targets for 2030.
Goals for 2020 agreed by EU leaders in 2007 became an international benchmark for climate ambition.
Scientific opinion has since become more convinced mankind is to blame for changes to the climate, but the political focus has shifted from the environmental to the economic crisis, especially in Europe.
European Commission President Jose Manuel Barroso said Europe has concerns about the impact on competitiveness if it acts when others do not, but he dismissed as "obscurantist forces" those who question whether the climate threat is real.
"If it's not more urgent (than economic crisis), it's more important because it's an essential threat to our planet. We should not relax our efforts. For that we need a global commitment. In Europe, we have been front-runners," he told Reuters.
The EU is still the main group among developed nations urging governments to declare their emissions goals.
EU Climate Commissioner Connie Hedegaard said all countries must "present bold pledges" in time for a summit organised by U.N. Secretary General Ban Ki-moon next September, which is meant to ensure the 2015 deadline for a new global deal is met.
Host of this month's climate talks, EU member Poland, whose economy depends on polluting coal, is among those who have emphasised collective action, rather than leadership.
Polish Environment Minister Marcin Korolec says EU efforts have handed an excuse to bigger emitters to leave the work to a bloc that emits a mere 11 percent of global greenhouse gases.
"This tendency of some European politicians stressing that the EU is a leader is in my opinion counterproductive," Korolec said, adding this only encouraged others to be inactive.
The biggest greenhouse gas emitters China and the United States have pledged to curb carbon, but on a modest scale.
China has promised to cut emissions per unit of economic output by between 40 and 45 percent on 2005 levels by 2020. As a reduction relative to gross domestic product (GDP), that will slow growth in emissions but not cut them.
The United States has said it will reduce carbon by 17 percent by 2020 compared with 2005, which equates to a fall of 3.5 percent below 1990 levels.
In Europe, recession and green energy use mean the EU has already nearly met its 2020 target of a 20 percent cut versus 1990 in greenhouse gas emissions, which include carbon and methane.
That could suggest bigger cuts would be easy, but instead divisions run deep on how many goals and what they should be.
Debate is expected to be intense at a March EU summit in Brussels on the proposed 2030 goals, which should be published in January, but are unlikely to be signed into law before 2015.
As industry and EU nations demand enquiries into the impact of green subsidies and carbon charges on a fragile economic recovery, some politicians say the bloc must retain its climate leadership to support industrial innovation and avoid long-term costs.
In October, a group of 13 EU environment ministers, who call themselves the Green Growth Group, urged prompt action. They are a counterweight to nations such as Poland, but alone does not guarantee a majority in a vote of the EU's 28 member states.
They are led by Britain's Environment Minister Ed Davey, who has pushed a British call for a 50 percent cut in carbon emissions by 2030 compared with 1990 levels.
Of this, 10 percent could be made up of carbon offsets bought on the global market and 40 percent would be domestic.
The 40 percent target is a doubling of the 2020 goal and EU sources say it is under consideration as part of the 2030 EU-wide package on climate and energy legislation.
Campaigners say it is not enough. Friends of the Earth, for instance, argues a 60 percent cut is needed for a good chance of capping temperature rises at 2 degrees Celsius, the limit which scientists say would prevent the most devastating consequences of climate change.
(Additional reporting by Stephen Adler and Luke Baker in Brussels, Susanna Twidale in London and Alister Doyle in Oslo; editing by Jason Neely)