We all want cleaner skies. We're even encouraged that governments, even airlines, are in agreement that reducing greenhouse gases is a good thing for everyone. Sadly, this is where the friendly handshakes and pats on the back end. Without a globally consistent way to deal with aircraft emissions, efforts to clean the air could reveal a dirty little practice.

Airlines around the world fear that the lack of a global aircraft emissions solution will entice individual governments to impose their own rules, creating a tangled web of taxation and fees. Recently, airlines protested a British government idea to double passenger taxes at U.K. airports as soon as 2010. Many airlines and their supporters denounced this as a new way for governments to raise revenue by disguising a tax as environmental policy. Carriers continue to insist that taxation schemes in the name of cleaner air don't take into account the fact that aircraft are becoming more fuel efficient and, with improvements in navigation and air traffic flow, environmental mandates can be met without the imposition of ad-hoc emissions schemes. What's counter-productive, they argue, is the barrier to compliance that additional fees could create. Cash strapped airlines could be hindered from investing in new aircraft and technology that would reduce emissions more quickly.

Asian carriers fear that similar attempts will be made across the globe. In an interview with Reuters, Dominic Purvis, Cathay Pacific's general manager for environmental affairs exclaimed: "What we don't want to see is a proliferation of regional schemes or regional and [sectoral] combinations or some weird and wonderful brainchild that applies in one country but not in others." Another sticky issue is the manner in which such emissions taxes or schemes could be implemented. The most comprehensive emissions trading scheme (ETS) belongs to the European Union which, from 2012, plans to include the aviation industry. Any airline using EU airspace will be affected. What many airlines object to is the likelihood that the scheme will include an aircraft's entire journey, even the distance outside of EU airspace. Both the United States and Australia are contemplating their own versions of an emissions trade system and, if the EU succeeds at implementing its all-distance plan, it's safe to say other countries will consider retaliatory measures. For an idea designed to reduce pollution, a lot of dust is certainly being kicked up.

The aviation industry produces just 2 per cent of the world's carbon emissions. However, when taken from a per-mile-(or kilometer)-traveled ratio, the industry is considered a high polluter. Given the fact that aircraft emissions are deposited very high in the atmosphere, it's hard to expect that the industry will find its way out of all environmental taxation or trade schemes. The question remains: can there be one, universal system, and what will keep that from happening sooner than later?