By Barbara Lewis

BRUSSELS (Reuters) - Fewer United Nations climate summits and more incentives through carbon pricing could speed up international efforts to slow the pace of global warming, a draft European Commission paper seen by Reuters says.

U.N. climate talks have yet to recover from a disastrous Copenhagen summit in 2009 when talks ended in failure and subsequent annual meetings have been heavily criticized for dragging on for weeks yet achieving little.

The most recent summit in Doha in December was unable to agree anything that would have an immediate impact on rising greenhouse gas emissions. Instead, it laid out steps towards a new global deal, scheduled to be agreed in 2015 and to enter into force from 2020.

The European Union has sought to lead with a set of green energy targets, including a goal to cut carbon emissions by 20 percent by 2020 versus 1990 levels and an EU-wide Emissions Trading Scheme (ETS).

A draft paper from the Commission, the EU executive, on shaping the next years of international climate change policy raises the idea of less frequent summits.

"Their open-ended participation and decision-making by consensus often results in only agreeing on the lowest common denominator. Moreover, the costs of this negotiating process are considerable," the Commission paper said.

Measures to make U.N. negotiations more effective could include getting rid of the rule that requires all decisions to be agreed by a consensus of nearly 200 nations and "revisiting the frequency" of the annual summits, while continuing smaller, technical meetings.

The Commission does not comment on unpublished drafts. However, EU officials have said the document will be debated by environment ministers next month.

Apart from tackling the U.N. process, the Commission also says increased focus on market-based instruments would help by providing "cost-effective" incentives to a lower-carbon society.

The European Union's ETS, the world's biggest carbon market, has collapsed to a series of record lows under a surplus of emissions allowances generated by recession.

Against the backdrop of financial crisis and worries about energy costs, the Commission has been struggling to push through reforms to strengthen the market, but still says the ETS is central to EU environment policy.

INCLUSIVE DEAL

Looking ahead to a 2015 UN deal, the Commission says it must include all countries and be binding.

The 1997 Kyoto Protocol on tackling climate change excluded emerging economies, some of which are now richer than the poorest parts of the European Union. The United States never ratified the deal, which expired at the end of 2012.

"The 2015 Agreement will need to address the challenge of attracting the participation of all major economies, including the U.S., China, India and Brazil that have so far resisted legally-binding commitments to reduce their greenhouse gas emissions," the document said.

To prevent the worst effects of climate change, scientists say warming must be limited to 2 degrees Celsius (3.6 degrees Fahrenheit). To achieve that, they say, greenhouse gas growth must be reversed before 2020 and decline every year afterwards.

Apart from the difficulty of persuading nations to agree ambitious emissions-cutting goals, another obstacle has been finance to help the poorest deal with climate change.

The 2015 agreement will need to mobilize private and innovative financing. One source could be an international price on aviation and shipping emissions, the document says.

EU law to make all aircraft landing in EU airports pay for carbon emissions provoked international outcry, including from the United States, which said it breached sovereignty.

As a result, the European Union agreed a temporary suspension of the requirement intercontinental flights have to pay into the EU ETS. Talks at U.N. body the International Civil Aviation Organization continue this month to try to agree an alternative global plan for aviation emissions.

(Editing by Marguerita Choy)