It is vitally important that we stabilise global temperature rises below the danger line of 2C – and the aviation industry stands in the way.

Probably the single most polluting thing that you or I will ever do is step on to a plane. Take that tempting return flight to, say, Thailand and you immediately become responsible for about six tons of greenhouse gases entering the atmosphere – three times more than is likely to come from any other activity that you do in the year, including driving and heating your house. This is why aviation is the most bitter and divisive issue in environmental politics today.

There is almost no consensus anywhere in this debate. Even my last paragraph will have caused annoyance for some: my six tons figure for the Thailand flight includes a 2.7x multiplier to account for the aggravating impact of greenhouse gases released by aircraft high into the atmosphere. However, citing scientific uncertainty, airlines choose to ignore this extra warming effect: if you use British Airways’ carbon calculator to assess my Thailand flight, it returns a figure of “only” 2.16 tons.

Not surprisingly, the industry downplays the impact of its activities. Stephen Nelson, chief executive of BAA, the airports operator, argues that aviation accounts for only 6% of UK carbon emissions and 3% of those globally. (These figures of course include no multiplier.) Aviation “should not be demonised, and we should not be cutting back on capacity at a time when people want to fly more”, he insists.

However, if air travel goes on expanding, all carbon reduction targets go out of the window. As the Tyndall Centre – the UK’s best known academic body specialising in climate research – reported in a 2006 study, aviation could account for 100% of the UK’s carbon allocation by 2050 in a climate stabilisation scenario. In other words, all other carbon-emitting sectors will need either to go zero carbon or to shut up shop, merely to allow for the growth in air traffic.

Tyndall Centre scientists are adamant that “there is no chance for the climate without tackling aviation” – and that means stopping the expansion of airport infrastructure. This is again where BAA comes in. The company is lobbying for a second runway at Stansted and is close to completing Heathrow’s terminal 5. It also wants to see a third runway at Heathrow and a sixth terminal to serve it. The company seems to have an umbilical relationship with the Department for Transport – everything that BAA wants to see happen, the DfT wants, too.

Most people hope for an eventual technical fix to the emissions problem. Sir Richard Branson has pledged billions for biofuels research, but even if technical hurdles – such as biofuels’ propensity to freeze at high altitude – could be overcome, there isn’t enough land out there to support the volumes of fuel that would be required without either displacing large areas of food production or further destroying tropical forests.

Nor does hydrogen offer much hope; it takes up more space than kerosene for the same amount of energy produced, and the water vapour emissions from burning hydrogen will still warm the climate. Nobody, not even airline PR people, claims that alternative fuels can be developed for at least another 30-50 years, much too late to help reduce climate change, which requires concerted action in the next decade.

You could offset, of course – but this is another thorny moral and political debate. Certainly it is true that offsetting does not reduce emissions – it simply allows them in one place while trying to mop up the damage somewhere else. However, I would argue that it is better to offset than not, particularly as most of the projects – from biofuel school stoves in India to rainforest restoration in Uganda – are worthy in themselves.

Environmentalists suggest that at the very least the aviation industry should pay as much tax on its fuel as everyone else. The Aviation Environment Federation has estimated that airlines pay just 18p per litre on fuel – helping to net the industry as much as £9 billion in hidden subsidies. But wouldn’t taxing aircraft fuel, thereby raising the price of tickets, simply price poorer travellers out of the market? Not necessarily. Most of the boom in low-cost air travel has been soaked up by rich people travelling more often. Surveys show that most people in the lowest social groups do not fly at all.

A better way to make the industry pay its environmental way would be to bring it into the European Union Emissions Trading Scheme. In principle, this would force airlines to buy enough credits to cover their activities within the context of an overall economy-wide emissions reduction. But the principle and practice are somewhat different. Governments are allowed to set their own national carbon caps each year. Airlines know their political power, which is probably why most say they are happy to participate in the trading scheme: if the squeeze got too tight, they could simply pick up the phone to the aviation minister.

The industry has grown too powerful for its own good. BAA certainly overplayed its hand in asking for an injunction against climate change protesters that would potentially have covered 5m people. In taking such an arrogant stance, BAA has helped to drive together an unusual alliance against it: from local communities, to direct action protesters, to the widening number of ordinary people who recognise the threat that aviation poses to our future. It is a movement that is growing rapidly in confidence and in numbers.

Like the police, BAA constantly invokes the terrorism threat as an excuse to stamp out protest, crying wolf in a political argument that it knows it is losing. Scientists revealed on August 9 that the Arctic sea ice had reached its lowest level in recorded history. With a further month of melt left to go, the experts expect that the previous record – set in 2005 – will be “annihilated”.

Don’t expect to read about this in a BAA press release or a government white paper. But do expect to hear a lot more about it from campaigners. The stepping up of direct action protests on global warming has come not a moment too soon.

© The New Statesman

Mark Lynas is the author of Six Degrees: Our Future on a Hotter Planet, Fourth Estate, £12.99

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