Guardian: Bully for Ed Miliband, committing the government to an 80% cut in UK carbon emissions by 2050 compared with 1990. The previous target, set in 2000, had been a 60% cut. All those who care about fighting climate change (which ought to be everybody) should be pleased. The only question is: how credible is it? Britain’s net CO2 emissions were 161.5m tonnes in 1990. A 60% reduction therefore requires that UK emissions should go down by 96.9m tonnes by 2050, and that implies that emissions …