The advent of aviation has made the world a smaller place, but in doing so it has burned up an inordinate amount of kerosene. And as with any fossil fuel, the more you burn, the more greenhouse gas you churn out.

So common has air travel become that it is now a huge problem for the environment. Greenhouse gases from all UK flights alone have doubled in 13 years to around 40m tonnes, a direct consequence of jet engines torching fuel to generate thrust. Vast amounts of carbon dioxide are dumped into the atmosphere, nitrogen oxides are released at just the right altitude to damage atmospheric ozone and particles from the engines attract droplets of moisture, seeding cirrus clouds that warm the Earth like a blanket.

Air travel accounts for somewhere between 3% and 5% of Britain's total carbon dioxide emissions, but passenger numbers are increasing so dramatically that emissions are almost certainly going to spiral out of control, experts warn. Estimates suggest that by 2030, CO2 emissions will have reached a total of more than 70m tonnes and the government's own white paper on aviation, barring any drastic clampdown, emissions from the industry will account for half to 100% of the country's target CO2 emissions by 2050.

Last month, the UK aviation industry published self-imposed targets to reduce emissions from aircraft by 50% by 2020, but it is a target that many see as ludicrously ambitious. "They honestly haven't got a cat in hell's chance of achieving it," says Kevin Anderson, an expert in aviation and the environment at the Tyndall Centre for Climate Change at Manchester University. "The argument that's often made is that you can improve efficiency and cut emissions that way. But jet engines are a mature technology and there are no big changes on the horizon that are suddenly going to make them wildly more efficient."

There are some simple changes that airlines are making to cut their emissions. Devising more direct routes, spending less time in holding patterns above airports and minimising the time pilots have their engines running while still on the ground can all help. But tightening up on what is essentially sloppy practice is not going to cut emissions drastically.

At best, according to a report by the Intergovernmental Panel on Climate Change (IPCC), the industry will be able to cut its emissions by around 1.5% a year purely by improving efficiency. "What that means is that any increase in passenger numbers beyond that figure will mean carbon dioxide emissions go up," says Anderson.

For the aviation industry, the available options for cutting emissions are limited and largely unappealing. Hopes that hydrogen fuel cells might one day carry us to 35,000 feet are futuristic, requiring planes to be redesigned from scratch. "There are simply no alternative fuels on the horizon. It's kerosene for the next 50 years," says Peter Lockley of the Aviation Environment Federation.

One way carbon dioxide emissions might be reined is by committing the European aviation industry to a cap and trade system for emissions as already exists for other industries. Such a move would put pressure on the industry to ferret out the most efficient ways to cut emissions, but according to Anderson, the system would soon become ineffective if passenger demand continues to increase.

Which leaves the industry with little room for manouevre. If the government is serious about its aim to cut the country's carbon dioxide emissions by 60% by 2050, as set out in the last energy white paper, it must either persuade other industries to cut emissions more or restrict the growth in air travel. "Realistically, other industries aren't going to make cuts just so the air industry can continue to expand. So the only real way forward is for growth to match efficiency improvements," says Anderson. "We're not saying don't fly, we're saying that we cannot fly very much more than we do now."