‘Just what is Tony up to?’ That was what one Labour MP asked, quizzically, when I bumped into them in Westminster this morning. Blair has made quite the splash with his latest political intervention, writing an introduction to a pamphlet that criticises net zero. The former prime minister warns that the debate on climate change had become ‘irrational’, with people in rich countries no longer willing to make financial sacrifices ‘when they know that their impact on global emissions is minimal’.