This Earth Day, a high-flying reminder from the Green Continent that what’s environmental is ultimately about what’s economic.

The world’s aviation industry says it’s taking climate change seriously, though it’s probably the bottom line that caught its attention. Either way, at the Third annual Aviation and Environment Summit in Geneva, airlines, airports, and aircraft makers all pledged for the first time to cut emissions.

Looking for gas money in the couch. (Associated Press)

Aviation accounts for about 2% of global emissions of greenhouse gases, although some scientists say the effect could be magnified because the emissions are high-altitude. Granted, that’s less than half as much as the cement industry—but aviation’s sheer visibility and relentless growth has made it a popular target for climate campaigners.

Now, the industry says it’s listening. Companies like Boeing and Airbus, and international aviation trade groups and airports, all signed off on a four-step plan to curb emissions from aviation. The four “pillars”: New technologies, including cleaner fuels; better fuel efficiency in fleets; more efficient air routes and air-traffic management; and “positive economic instruments” to cut GHG wherever it’s “cost-effective.”

What’s the common denominator there? Hint: Jet kerosene now costs $145 a barrel. And there’s no easy way to “hedge” against higher fuel prices when crude is $118 a barrel.

Higher fuel prices hammer airlines. Fuel has overtaken labor costs as airlines’ No. 1 expense, and that takes some doing. U.S. airlines, already fretful that a slumping economy will stint air travel, got drygulched this earnings season by higher fuel prices. Cost savings, even from fuel, is one of the factors behind the Delta-Northwest merger.

Airlines got the green bug a few years ago when fuel prices started rising. That explains the appeal of newer aircrafts, like Boeing’s Dreamliner, which uses lighter materials and new-generation engines to cut fuel consumption. Airbus’ big answer, the superjumbo 380, is to pack more passengers into a plane—which means lower unit costs for fuel, among other things.

The other pillars in Geneva address the same concerns. Airlines hate zig-zag air traffic routes that make them burn fuel dodging military no-fly zones. Airlines hate antiquated air traffic rules that make them stagger-step down for landing, or circle endlessly, burning extra fuel. And airlines are scared to death that Europe will see them as an easy target as it seeks to revamp economy-wide limits on greenhouse-gas emissions.

So what’s the answer? Bail us out, please. The summit’s declaration calls for governments to help finance research into new technology, revamp air traffic, and to make sure that any global climate change accord is “equitable.” In other words, a new meaning for the term “flag carrier.”