If you think climate change activists like me will take the decision over airport expansion lying down, you’ve got another think coming

Here we go again.

Ten years ago last month, I joined 24 other brave souls and a Baptist Minister to cut through the fence at Nottingham East Midlands airport, where we held a sermon on the runway. This was Plane Stupid’s first ever runway occupation, in defiance of government policy backing a trebling of passenger numbers and massive expansion at dozens of British airports. The UK did not yet have a Climate Change Act, but it was already clear that aviation was now the fastest growing source of greenhouse gas emissions, and that government policy pushing this could not be squared with effective action on global warming.

I went on to be taken to the High Court by BAA, scale the House of Commons, take part in a mass occupation of the runway at Stansted and help my comrades to superglue themselves to Gordon Brown and slime Peter Mandelson. But all these (and many more) direct actions were themselves just one small part of an unprecedentedly broad and diverse movement that mobilised against a third runway at Heathrow. Environmental NGOs and development charities, local MPs and councils of every hue, grassroots noise campaigners and the Mayor of London all took up the cause. At the centre of everything were the members of the communities that would disappear beneath the tarmac if the third runway went ahead.

The sheer force of our collective will eventually brought the weight of public opinion behind us, and the fate of the third runway was sealed – “no ifs, no buts”. David Cameron even planted a tree on the site to commemorate its passing.

The tree died. But the third runway lived on, in the hopes and dreams of Britain’s aviation lobby. Today, it is rising remorselessly like a zombie from the grave, clawing its way to the top of the political agenda once again. Why won’t it stay buried?

Former MP Chris Mullin gives some clues in his account of his time as aviation minister: “I learnt two things. First, that the demands of the aviation industry are insatiable. Second, that successive governments have usually given way to them.” The cosy relationship between the Department for Transport and the aviation industry was laid bare in 2008, when officials were reported found to have been colluding with Heathrow to engineer the outcome of air quality assessments needed to approve expansion.

Heathrow and Gatwick have reportedly spent over £30m each on PR and lobbying since the elaborate political long-grassing exercise that was the Airports Commission began its deliberations over where to put new airport capacity in the South East. This was the wrong question (of which more in a moment) but the framing of the Commission has conspired with the huge marketing budgets of the rival airports to conjure up an “airport capacity crisis” for London.

This is now the new common sense – our airports are full, and delaying new runways is doing irreparable harm to the British economy. This hysteria climaxed in the summer with the comical claim that these delays are costing us £6m a day. But it seems to have worked. Labour’s shadow aviation minister Andy MacDonald sums up the new paradigm thus: “It is beyond doubt that additional capacity is needed. The imperative is overwhelming.”

Neither is true. Stansted’s runway slots are half empty. The direct contribution of the aviation sector to the British economy (£18bn) is less than the combined value of the annual tax subsidy it enjoys (£11bn) and the UK’s gaping tourism deficit (£17bn and rising). Only one in ten international flights by UK residents is now for business, and the proportion goes down a little more every year. The latest incarnation of the runways debate has been almost magically effective at conflating the financial interests of the big airport owners with the national economic interest.

Airport capacity faces a profound challenge in the shape of climate change. Aviation has a uniquely generous target under the Climate Change Act: absolutely no reduction in emissions, while the rest of the economy must make up the shortfall with extra cuts. Yet the aviation sector is still set to break the budget. The problem is that annual growth in demand for flights greatly outstrips efficiency improvements – by a rate of about five to one, globally.

In the UK, the Committee on Climate Change has advised that for aviation to comply with the Act, demand growth must be limited to around 60 per cent to 2050. But the Department for Transport expects demand to grow over this period by 93 per cent; this is the extra demand which a new runway is clamouring to cater for. The solution is clear, but horrifies politicians: we will have to have policy to manage the growth in demand. There is simply no other way.

Eventually, if the UK stands by its commitment to tackle climate change, some government must grasp the nettle of demand management. When it does, we will be ready. Demand growth for air travel is driven by lavish tax breaks on fuel duty and VAT which keep air fares artificially low. A frequent flyer levy that shifts tax off ordinary holidaymakers and on to frequent flyers would benefit the large majority of UK residents. Those who would have to pay more are those who can most afford to. Modelling shows that it could keep aviation emissions within safe limits at the same time as distributing flights more evenly across the income spectrum, and raising more money to support alternatives.

In the meantime, people will just have to rise up once more against the green light next week. Heathrow is set to become a lightning rod for radical climate activists all over the country, and the old networks from the former alliance are starting to light up again for the first time in years. Once more, dear friends, once more – but let’s make sure it’s really dead this time.

Leo Murray is a co-founder and former activist with Plane Stupid. He is currently campaigning for a fairer tax on air travel at afreeride.org.