John Sauven: We <i>do not</i> need a bigger Heathrow

Gordon Brown surrendered his credibility on climate change yesterday. He instructed his Transport Secretary to stand up in the Commons and claim a new runway at Heathrow could actually help to cut carbon dioxide emissions by 80 per cent by the middle of the 21st century. In reality, the airport would become the single largest source of CO2 in Britain.

Thankfully, this runway will never be built. Not only does Greenpeace and more than 15,000 people now have a legal stake in the land but the public will never accept such a wilful ignorance of climate change science. Ministers and their friends in the aviation industry may try to greenwash this announcement but the facts remain. A third runway alone would emit millions of tonnes of climate-changing carbon dioxide. Geoff Hoon's claim that the Government will only let so-called "greener" planes use this £9bn white elephant beggars belief. Modest improvements in engine efficiency do not change the fact that large aircraft are huge sources of CO2. His attempt to promote biofuels as an alternative to jet fuel will only exacerbate the problem.

Hoon also attempted to drop another artificial sweetener into this brew: a high-speed rail line to connect the airport to the North. There is only one problem – a new railway can only reduce emissions if it replaces extra airport capacity. If it is built next to an expanded Heathrow, it is like slapping a nicotine patch on as you light another cigarette.

If the Government is truly committed to making the railways a viable alternative to domestic and short-haul flights, it would build a new high-speed line instead of a third runway. In Spain, a new rail link has led to a 20 per cent drop in domestic flights in the past year alone.

John Sauven is the executive director of the campaign group Greenpeace.