In the utopian vision of net zero pledges, there will be no new petrol cars on EU roads from 2035, American industry will run on green hydrogen, wind farms will whirr across the North Sea, and solar power will bring all Africans affordable energy.
The IMF claims all this can be achieved without straining government finances.
Estimates by its staff, presented at a recent conference, suggest that co-operation on decarbonisation could ensure countries meet their net zero targets at an overall economic cost of just 0.5 per cent of what global GDP is expected to be by 2030. For most countries, the fiscal impact would be positive or neutral by the end of the current decade, although some would incur later losses.