NEW YORK (Reuters) - The way some of the big U.S. airlines tell it, they’re responsible stewards of the environment working hard to shrink their footprints.

An airplane flies near a gas flare from a factory at Keihin industrial zone in Kawasaki, south of Tokyo June 10, 2009. REUTERS/Toru Hanai

American Airlines, in an article in its in-flight magazine American Way, says the company is “committed to identifying and implementing programs to reduce our environmental impact.” Just this week, American announced the purchase of 460 new fuel-efficient aircraft.

The newly merged United Continental UAL.N recently launched an "Eco-Skies" campaign that, according to a company web site, reflects "a common focus on protecting the environment" and "allow(s) us to integrate our programs and focus on the environmental commitment of our combined company."

So why are these environmental stewards hiring lobbyists and going to court to fight common-sense rules that will help protect the environment? And why are some members of Congress introducing legislation that would make it illegal for air carriers to obey new European clean air standards?

On January 1, 2012, all civil aviation flights using airports in Europe will become accountable for their global warming pollution. A new European law, designed to reduce global warming emissions from aviation as part of the larger effort to avert climate catastrophe, will apply to all airlines without regard to nation of origin. (The law exempts airlines that operate a small number of flights to/from the EU).

In its first year, the law requires the airlines to make a modest three percent reduction from their 2004-2006 emissions levels, and to cut pollution 5 percent through 2020. The law gives airlines broad flexibility to determine how to reduce pollution.

Innovative carriers that cut emissions below required levels can sell their surplus allowances. This mild law won’t hurt the carriers’ business; in fact, a 2007 study by the industry’s International Air Transport Association found that the regulation’s “net impact is slightly positive for (both) the profitability of airlines operating extra-EU flights and the overall profitability of flights arriving and departing the EU.”

Instead of complying with the EU law, the American carriers United/Continental and American Airlines are doing what companies often do when they don't like a law or regulation: they're going to court and hiring lobbyists. On July 5, a Grand Chamber of the European Court of Justice ECJ.L held a day-long hearing on the airlines' challenge to the EU-ETS Aviation Directive.

This week, House Transportation and Infrastructure chairman John Mica (R-FL) introduced the European Union Emissions Trading Scheme Prohibition Act of 2011, a bill that would actually make it against the law for US airlines to participate in the European system -- even just to report their emissions.

The House bill mirrors language the carriers’ lobbyists have already inserted into pending legislation declaring that the EU aviation law is illegal under international law and that the administration should use all available legal, political and diplomatic means to make sure US airlines don’t have to comply.

In talks with the Europeans in Oslo last month, some Obama administration officials, at the behest of the airlines, raised objections to the EU program. To date, however, the President has avoided weighing in -- wisely so, since taking the airlines’ side would put the President in the position of international scofflaw if, as looks likely, Europe’s highest court affirms the regulation.

The arguments the airlines and their supporters in the House make in opposing the law range from the implausible to the absurd. They claim, for example, that the EU law is a violation of U.S. sovereignty and illegal under international law and the Chicago Convention, the treaty that regulates international air travel.

But the EU law only holds the U.S. airlines accountable for their emissions if they land in any nation of the EU. The law does not require anything for flights outside the EU. In that regard it’s like many American laws that set requirements for aircraft and ships coming in and out U.S. territory. A good example is the U.S. law passed after the Exxon Valdez spill. That law requires all ships carrying oil in U.S. waters to be equipped with a double hull -- even though that means tankers must have double hulls when they leave their ports of origin in Europe or anywhere else.

The airlines also claim the EU law will generate more pollution, alleging that airlines will re-route via intermediate airports to escape the additional costs of flying into Europe. That claim is simply preposterous. With fuel prices at record highs, the costs of rerouting simply to avoid the EU law would far exceed the costs of complying with the law. Airlines respond to the demands of their passengers, and no passenger flying between Johannesburg and Frankfurt, for example, wants an extraneous stopover in Addis Ababa or Cape Verde.

Nor is cost of compliance is an issue. Estimates of the cost of compliance for airlines range from a high of roughly $50 per ticket and downwards per long-haul seat. If that cost sounds high, consider this: in 2009 the UK instituted a roughly $80 per ticket air departure duty with no significant decrease in traffic observed.

It’s bad enough in this year of runaway heat waves, drought and flood, to deny that greenhouse gas reductions are necessary. But for the airlines to fight common-sense regulation while heaping on the hypocrisy by touting their green credentials is even worse. It’s time for American and United/Continental, as my daughters would say, to “get real’. It’s time for the carriers to explain to the public and their passengers why they don’t want to step up and do their share to curb carbon emissions.