The United Nations climate change talks continue in Doha, Qatar. President Obama is not expected to attend. But he has signed a law protecting U.S. airlines from more strict climate change regulations.

If you fly from the U.S. to Europe and back, you add about two tons of greenhouse gas to the friendly skies. The European Union passed a law to charge fees for that pollution. Under protest from the U.S., China and others, it just postponed implementing that law next year. Now President Obama has signed a bill that says U.S. airlines won't have to pay the E.U.'s carbon fees.

"Then you have a bunch of emissions that is nobody's responsibility," says Jake Schmidt at the Natural Resources Defense Council, "and unfortunately the planet keeps getting hotter."

Schmidt says the heart of the bill Obama signed is the idea that no foreign body should regulate U.S. industry. That thinking is not the most fruitful for combatting global climate change, he says.

Airline industry anaylst Helane Becker at Dahlman Rose says U.S. airlines have plenty reason to get more green on their own: the price of jet fuel.

"The last three or four years the fuel bill for the airline industry has doubled and tripled," Becker says.

She notes that U.S. companies are building lighter planes and more efficient engines, in addition to aggressively testing biofuels, as means of bringing down fuel costs. Pollution from airplanes will lower as those efforts bear fruit, but these are voluntary efforts with no guarantees on the levels or timeframes for reduction.