Flights at Stansted were today grounded after at least 50 climate change protesters broke into the airport and occupied a runway.Activists cut through fencing and once on the landing strip chained themselves together and surrounded themselves with their security fencing to create a ‘fort’.Members of the Plane Stupid organisation, who are protesting against the proposed second runway, grounded flights after achieving their aim of closing the airstrip. The occupied runway had been due to reopen at 5am. Airlines were told to divert their planes in the skies and, although the airport terminal has been opened to passengers, no aircraft...