The statement by Geoff Hoon, Secretary of State for Transport, on 15 January about the Government’s proposal to build a third runway at Heathrow airport drew predictable criticism from those concerned with its environmental impact.  While noise and local noxious emissions might be ameliorated by cleaner, quieter aircraft, it is hard to see how substantial growth of flying could be compatible with an overall reduction of carbon emissions by 80% by 2050, the Government’s declared target.

The Government’s attempt to reconcile seemingly contradictory stances is worth considering carefully, however.   It argues that carbon dioxide emissions from international aviation are included in the EU 20% greenhouse gas reduction target for 2020.   Under the EU emissions trading scheme this reduction will occur whether or not Heathrow is expanded.  With a fixed cap for aviation across Europe, doing nothing at Heathrow would allow extra capacity at other hub airports like Frankfurt, Schipol and Charles de Gaulle.  So not building the third runway at Heathrow would damage the UK economy and have no impact what so ever on climate change.

Mr Hoon announced funding of £250 million to promote the take-up, and commercialisation within the UK, of ultra low emission road vehicles. With road transport emissions so much greater than aviation’s, even a relatively modest take-up of electric vehicles beyond 2020 could – on its own – match all the additional carbon dioxide generated by the expansion of Heathrow, he believes.  Mr Hoon also intends to establish a new target to get aviation emissions in 2050 below 2005 levels and has asked the Committee on Climate Change to advise on the best basis for this development.

The Government claims to have the toughest climate change regime for aviation of any country in the world, and to be confident that the UK will achieve its 80% emissions reduction target.   Is this credible? 

It has to be allowed that the purpose of an emissions trading scheme is to achieve an overall cap on total carbon emissions which reduces over time, within which context it should not matter from which sector reductions are made.   Nevertheless, it seems a bad idea to allow large new sources of carbon emissions, whether runways or coal-fired power stations.   Since carbon emissions are cumulative, what matters is not just the ultimate target but also the trajectory to get there.   A big technology switch to low carbon late in the day would result in more ice cap melting etc than would steady progress in this direction in the years to 2050.  

Mr Hoon plans to constrain the increase in carbon dioxide emissions from the third runway by limiting the initial extra capacity to around half of the original proposal and by specifying that new slots will have to be ‘green slots’ for use only by the cleanest planes.  Given that the new runway would need to be funded and built by the airport operator, it will be interesting to see what impact these constraints, as well as the overall carbon reductions target, have on the business case for raising finance.

The challenge of our time is to reconcile economic development, including air travel, with the need to tackle climate change. The Government’s stance on Heathrow is unconvincing.   The sooner the Committee on Climate Change addresses these issues the better.