Leading article: The true cost of cheap flights

The budget airline revolution is showing no signs of slowing. On 4 July EasyJet will offer its customers the opportunity to fly from Glasgow to Marrakech. This will be the first time a budget carrier has offered a flight outside of Europe

In the past decade, cheap flights have resulted in millions more of us making trips by air to European destinations. The budget airlines are now likely to have a similar impact on visits to destinations outside Europe too. There is no reason to believe that EasyJet's ambitions stop in Morocco. And given the highly competitive nature of the budget sector, other carriers are likely to follow.

This is deeply concerning from an environmental perspective. The boom in European air travel generated by cheap carriers is already threatening to wreck our attempts to bring climate change under control. Britons are forecast to take 101 million foreign trips by 2020. The continued expansion of budget airlines means that we are likely to hit this target even sooner. And if people are to be travelling greater distances, there will be a corresponding increase in carbon emissions.

If ever there was a time for the international community to give serious consideration to some form of global tax on air travel, it is now - before this new trend sets in. Yet it would be wrong for governments to penalise cheap flights alone, since this would hit primarily the less well off. Such a levy should affect all air passengers equally. A tax on airline fuel is the obvious solution. The fact that the airline industry has been allowed to operate for so long paying no tax on their fuel is a scandal. With no incentives to conserve fuel or cut pollution, it is little wonder that the airlines are responsible for such a high proportion of the world's carbon emissions.

France proposed a tax on aviation fuel at last year's G8 summit in Gleneagles. And the proposal won support of 66 countries at a United Nations meeting last year. This is an idea that cannot be resisted forever, particularly as the drastic affects of climate change become ever more apparent to us.

Governments and consumers alike must adopt a more responsible view of air travel. No one would argue that we ought to return to the days when only the rich could afford to fly. But there needs to be some recognition of the damage that each flight does to our environment.

Cheap foreign air travel is undeniably an attractive and liberating thing. But it comes at a price. And it is time that we began paying it off ourselves, rather than leaving the bill for future generations.