Carbon capture and storage is a simple idea. As the carbon dioxide comes out of a steel mill, cement works or chemical factory, capture it and feed it into a pipeline before it gets into the atmosphere. The pipeline leads to an old oilfield or deep mine and is pumped underground to be sealed for all time and so save the world from global heating.

Britain is committed to spending £30bn on this technology, which is a get-out-of-jail-free card for heavy industry and a magic way of getting to net zero without having to actually cut emissions.

The trouble is that engineers have been trying to perfect a method of doing it for years and it has not been successful. It is hard to find suitable places far enough underground and at sufficient pressure to compress the carbon dioxide and be sure it will stay in place.

A new report says that worldwide, the maximum reduction that carbon capture and storage could manage for the atmosphere would be 0.7C, far short of the 5C to 6C industry and governments claim.

The conclusion: if we want to save ourselves from ever more dangerous weather there is no alternative to halting the production of carbon dioxide in the first place.