The UK is guilty of "leaving behind a black hole where detailed policy and a plan of implementation ought to be" after setting its 2050 net zero target, a former BBC director-general has said. Lord Birt also slammed the government’s decision to commission Chris Skidmore to carry out a review into delivery of net zero, saying it was effectively "an overt declaration that the government were not wrestling with and resolving the host of unsettled issues" he identified.