The European Union proposed that the shipping and airline industries reduce greenhouse-gas emissions by as much as 20 percent over the next decade as part of any new United Nations accord to fight global warming.

Ships would have to cut greenhouse gases by a fifth in 2020 compared with 2005 and airlines would need to trim discharges by 10 percent during the period under the EU proposal to the UN. European environment ministers endorsed the negotiating position at a meeting today in Luxembourg.

The 27-nation EU is pressing the U.S., China, and India to accept a new UN treaty to counter the heat waves, storms and floods tied to global warming. The UN aims at a December meeting in Copenhagen for an agreement that would succeed the Kyoto Protocol after it expires in 2012.

“We must maintain momentum towards the December deadline” and seek an “ambitious deal,” said U.K. Energy and Climate Change Secretary Ed Miliband. The Swedish govenment, current holder of the EU’s rotating presidency, pushed through the proposal over resistance from maritime countries including Greece, Cyprus, and Malta.

Europe wants the world to tackle transport emissions after the 1997 Kyoto treaty excluded the maritime and aviation industries from reduction targets for greenhouse gases including carbon dioxide, the main such pollutant. Last year, the EU approved legislation that will cap CO2 from domestic and foreign airlines serving European airports as of 2012.

The EU law will add air carriers to the European emissions- trading system, which imposes CO2 quotas on energy and manufacturing companies and requires those exceeding their limits to buy spare permits from businesses that emit less.

The bloc, which accounts for 25 percent of the world’s shipping fleet, has so far held off imposing similar curbs on maritime emissions in order to allow for a coordinated global approach. Environmental groups hailed the new EU initiative.

“We welcome the first proposals for global targets to reduce carbon emissions within the aviation and shipping sectors,” said the European Federation for Transport and Environment. The World Wildlife Fund called the plan “a significant step forward.”

As part of their initiative, the EU environment ministers urged the use of “market-based instruments” worldwide to cut greenhouse gases from ships and planes. The ministers said these instruments should be developed within the International Maritime Organization and the International Civil Aviation Organization.

Europe’s goal at Copenhagen is to make fossil-fuel use more costly and turn the European emissions-trading system into the cornerstone of a global market. In that context, the EU is pressing wealthy economies to commit to reductions in greenhouse gases by 2020 and offer aid to poor countries.

In return, Europe wants developing nations such as China to commit to limiting emissions growth in 2020 to 15 percent to 30 percent below “business as usual.”

The EU is already on course to cut such pollution by a fifth in 2020 compared with 1990 and is willing to deepen its reduction target to 30 percent over the period provided other rich economies follow suit.