The world's airlines have committed themselves to a global cap on emissions in 2020, even allowing for a return to growth after the worldwide economic slump, the industry chief said Monday.

The fuel-hungry air travel industry, which has been under attack from environmentalists for its contribution to global warming, faces estimated losses of 20 billion dollars in 2008 and 2009.

But despite the global financial crisis, the International Air Transport Association (IATA) said at its annual meeting here that carriers had set an ambitious environmental goal that other major industries had yet to strive for.

"Two years ago we set a vision to achieve carbon-neutral growth on the way to a carbon-free future. Today we have taken a major step forward by committing to a global cap on our emissions in 2020," IATA chief Giovanni Bisignani said.

"After this date, aviation's emissions will not grow even as demand increases. Airlines are the first global industry to make such a bold commitment," he said.

Earlier, the IATA director general said a new forecast pointed to a nine-billion-dollar loss for the airline industry in 2009 on top of a revised estimate of a 10.4-billion-dollar loss for 2008.

"There is no modern precedent for today's economic meltdown. The ground has shifted. Our industry has been shaken," Bisignani told the meeting.

"This is the most difficult situation that the industry has faced."

He said that in 2009, the carbon footprint of air transport was expected to shrink by seven percent.

"Of this, five percent is due to the recession and two percent is directly related to efficiency gains from IATA's four-pillar strategy," he said, referring to improved technology, effective operations, efficient infrastructure and economic measures that governments have to implement.

"No other industry is as united. And no other industry can point to such good results and progress," he added.

Bisignani said the International Civil Aviation Organization (ICAO) must set binding carbon emissions standards on aircraft manufacturers.

Legal and fiscal measures must be put in place to promote "sustainable biofuels" and governments must work with navigation service providers to foster infrastructure projects that will reduce emissions, he said.