I have a theory about intra-Johnson family politics. Some time in 2017 or 2018 Stanley agreed to shut up about his opposition to Brexit if Boris dropped his climate scepticism and threw himself wholesale into green issues. A truce between father and son certainly seemed to emerge around that time, and Boris, the man who a few years earlier had written that wind farms ‘couldn’t pull the skin off a rice pudding’ was reborn an environmentalist.