There’s been a minor ding-dong in the UK with a leaked report from Chancellor Philip Hammond warning the ‘cost’ of meeting a proposed ‘net zero’ 2050 target for climate emissions will be £70bn a year, compared to the Committee on Climate Change’s estimate of £50bn a year. To put that figure in context, £70bn is about 2.5% of current GDP.

One immediate response is how on earth do you put a price tag on saving society? Surely you plan to save society and then work out how to pay for it.

But even if we take the dry economics, The Stern report in 2006 estimated the economic costs of not tackling climate change as 5% of GDP. If that figure is still extant, then the cost-benefit analysis says ‘go for it!’. [I really struggled to find a more recent assessment than Stern, btw, as the IPCC has shied away from the controversy, although one figure for economic impact was 2%]

In any case, the Government looks likely to set the target regardless. I suggest the number crunchers at the Treasury relish the challenge of finding the most economically efficient way of meeting that target. After all, the people of the UK are demanding it.