Major airlines warned on Wednesday that failure to agree a global approach to emissions trading in climate change talks could hurt their industry by leading to increased taxes and regulation.

"I think Copenhagen is very important for the airline industry, we must play our part," British Airways chief executive Willie Walsh said at a conference in Geneva, referring to the UN's climate change talks in Copenhagen in December.

"If we don't see progress at Copenhagen, I think the industry will suffer," he cautioned, acknowledging that some of the criticism of the approach taken by the aviation industry to environmental concerns "has been fair."

Airlines have long complained about the European Union's Emissions Trading Scheme, into which carriers operating in and out of the bloc would be included from 2012, saying it will hamper their operations in the region.

Swiss International Airlines chief executive Christoph Franz said that such a piecemeal regional or national approach could actually lead to more greenhouse gas emissions as airlines sought to fly around EU airspace.

"It is urgently necessary to create a global scheme," he told the two-day Aviation and Environment summit here.

The aviation industry's contribution to Copenhagen is meant to be distilled by the 190 government representatives in the International Civil Aviation Organisation (ICAO), a UN body.

However, the ICAO's talks are riven by divisions between developing and wealthy nations that broadly mirror the rift that has marred attempts in recent years to reach a global agreement to cap emissions, officials said.

Many airlines fear they will be cast as the villains if Copenhagen fails, even though they are trying to cut emissions from air travel.

"International aviation is ready and willing to be included as part of the next global climate deal and we need ICAO's leadership to drive the industry forward," said Paul Steele, head of the Air Transport Action Group, a lobby encompassing airlines, airports and aircraft makers.

Several technical measures intended to cut emissions further were announced at the meeting, including modified flight procedures and progress towards using "sustainable" biofuels on current aircraft.

However, feedstock or crops for alternative fuels are far more costly than crude oil. Carbon trading is regarded as key because it provides an additional incentive to save jet fuel by setting a financial cost for emissions.

The aviation industry also wants the money they spend on carbon credits ploughed back into "green" research and development for civil aviation.

"That's the problem with emissions trading, there's no clarity on where the money is spent," said Samer Majali, chief executive of Royal Jordanian Airlines.

Air transport contributes around two percent of global CO2 emissions according to the Intergovernmental Panel on Climate Change.

But international air travel has not been included in previous deals to regulate emissions, such as the Kyoto Protocol.

World leaders will be trying to negotiate a new climate deal to succeed Kyoto in Copenhagen.