On almost every level the chancellor’s decision to expand the London airport looks naive, if not foolish

For 20 years, politicians, industry leaders and campaigners have fought in courts, parliament and public meetings over the idea of building a new runway for Heathrow. For some, a third runway would not only boost passenger numbers at the airport but would be a symbol of the country’s determination to seek economic regeneration. For others, it would demonstrate, in vivid terms, our complete failure to understand the grim, global threat posed by further increasing carbon emissions.

Last week, Rachel Reeves chose to enter the fray. Remarkably, for a supposed green chancellor, she elected to back the project and seek the expansion of Heathrow to raise its annual passenger capacity by 50% to about 140 million. “A third runway at Heathrow would unlock further growth, boost investment, increase exports and make the UK more open and more connected,” she claimed. It was a bold move. It is unlikely history will view it as a sensible or justifiable one, however. On almost every level – political, local or environmental – her decision looks naive, if not foolish.