Guardian: BAA has admitted that the opening of a second runway at Stansted airport will be delayed by two years because there are not enough passengers to meet demand. Amid warnings from green campaigners that the admission undermines the case for expansion, Britain’s third largest airport will instead open a new runway in 2017 if it secures planning permission at a public inquiry due to start in April. The airport’s owner, BAA, said the economic downturn had affected passenger demand …