18/01/2012 11:44 GMT | Updated 19/03/2012 05:12 GMT

Why a New Airport in the Thames Estuary is a Complete Flight of Fantasy

The UK government has been talking about building a new airport in the Thames estuary for over 30 years. And every time a new plan is put forward, it's been rejected -- for very good reasons.

Historically, Thames estuary airports have never got off the ground because they have been deemed too expensive to build, wouldn't attract the traffic needed to be financially viable, lacked local council support, would create major noise pollution for residents and destroy world-class wetlands which are rich in birdlife.

All of these reasons for not building a new airport still exist and prompt much discussion. But absent from this list is the biggest reason of all - climate change.

Aviation is the fastest growing source of UK carbon emissions, contributing to 13% of climate damage according to the Government's own figures. The UK Climate Change Act has set a legally binding target to reduce emissions by 80% by 2050 and aviation is expected to contribute to the achievement of this target. But how can it if a new Thames estuary airport creates what is likely to be the single biggest source of carbon emissions in the UK?

Funnily enough, the 'growth at all costs' aviation and business lobby, which is currently behind the siren calls for expansion, never once refer to the climate costs that a new Southeast airport would have. Or how it would be compatible with meeting UK climate targets--or the advice of the Committee on Climate Change, the Government's climate advisers, who recommend that aviation emissions return to 2005 levels by 2050.

According to WWF research on available airport capacity, there is only a 1% shortfall in Southeast runway capacity to 2050, in line with meeting UK climate targets, once you allow for larger planes and higher aircraft loading -- which hardly justifies building a new airport. And once you factor in all the other trends which favour alternatives to flying such as HS2, which the government says will replace 4.5 million flights, and greater use of videoconferencing, used by over 60% of large UK companies to permanently cut flights (, there will be even more spare capacity available.

Another argument made for expansion is a loss of competitiveness to continental airports, at a cost to the UK economy. We probably do need a few more flights to China and Brazil, using spare capacity at other London airports, but let's not lose sight of the fact that Heathrow has by far the best connectivity to emerging markets such as India and South Africa, in addition to unbeaten links to the Middle East, many parts of Asia and North America.

Ultimately, it's not about having the greatest number of destinations that matters to the economy, it's having the most flights to key business destinations - which Heathrow already has.

Finally, circulating in the aviation industry is the bizarre assertion that having more air routes will magically lift the UK out of recession. But air routes don't create business - business creates business! And building a new airport to 'predict and provide' all these new routes will simply lead to unconstrained airport growth and unfilled planes - a model of thinking that has long been rejected as a justification for roadbuilding.

Which brings me back to climate change. Let's not forget that the previous government plan to build a third runway at Heathrow was rejected by the UK High Court on the grounds that it didn't sufficiently consider developments in climate change policy or legislation. It seems inconceivable that a new Thames estuary airport will pass the climate test, without this government running roughshod over the UK Climate Change Act.

So why does building one more London airport really matter, in the scheme of things? Because it is yet one more decision to build high carbon infrastructure, which reduces the world's chances of avoiding dangerous climate change. The UK has always punched above its weight in terms of global influence. If we build more airports, we'll be encouraging other countries to do the same. But if we refuse to build more airport capacity in the Southeast and use available capacity better, allowing growth within environmental limits, we'll be showing the world how to move to a lower carbon economy without having to sacrifice competitiveness.