Sir Keir Starmer’s legislative plan to green Britain has arrived not a moment too soon. Last week, the government’s advisers warned thatonly a third of the carbon reductions required by law would be met under existing plans. The Climate Change Committee said that, for the first time since setting itself carbon-reduction targets, the UK is not on track to meet its goal. It is supposed to reduce emissions in 2030 by 68% compared with 1990 levels, to meet net zero by 2050.