In July, the world watched as record levels of rain fell on parts of Germany and Belgium, causing widespread flooding. More than 200 people died after rivers burst their banks, many homes and livelihoods were destroyed, and the long-term economic impacts are expected to run into many billions of euros.

As well as its devastation, the event was notable because local officials were quick to blame the extreme weather on global warming. During a visit to one of the worst-affected areas, the premier of North Rhine-Westphalia, Armin Laschet, said the region would be “faced with such events over and over, and that means we need to speed up climate-protection measures”.

Just two months later his strong words were vindicated. A team of 39 scientists at international network World Weather Attribution produced a ‘rapid attribution study’ showing that climate change had increased the risk of the heavy rain by between 1.2 and 9 times and made the rain itself between...