More on global warming from Christopher Monckton...

Last week, we blogged his first article for the Daily Telegraph...now, here's his second.

Sir Nick says if we spend 1 per cent of GDP now and for ever we can reduce "the chances of temperature rises of 4-5C and above – at which levels some of the worst impacts occur". The crucial number when evaluating the income stream from forward investments like this is the discount rate: the annual percentage by which any forecast of tomorrow's revenue is cut to allow for the risks inherent in not getting it today. Stern discusses the rate at length, and even has a technical annexe on it, but, astonishingly, not once in 700 pages does he put a figure on it. I gave his team 24 hours' notice of the question: What discount rate or rates, and why? Six hours after my deadline, as the Treasury was closing, they said they might answer "next week". The following morning, with the page held for my copy, I rang and asked again. "There's nobody in who worked on that part of the report," they said. But they admitted they'd used several rates, all of them low because "if you're richer in future you value each unit of output a bit less", and because they hadn't discounted the future just because it was the future as that would be intertemporally inequitable (in English: not fair to the kids). Too low a discount rate makes spending 1 per cent of GDP now look cheaper than waiting.

They are also coy about what value our $500 billion a year would buy us. They say that if the world stabilises atmospheric CO2 at about 485 parts per million we'll have spent 1 per cent of GDP to get – er – a 1.1 per cent fall in consumption. If we stabilised at 400ppm, consumption would fall by only 0.6 per cent, but that's a pipedream: we're at 380ppm already, and, on Stern's figures, we'll reach 400 in just eight years.

By 2035, says Sir Nick, temperature will have risen by "over 2C". It sounds alarming. What he means, though, is over 2C since 1750, when we don't know what the temperature was. Stern's 485 parts per million by 2035 is based on the UN's worst case. Even then, the increase compared with today would be just 0.7C. On the UN's lower projection, implying 425ppm by 2035, only 0.3C.

The UK accounts for just 2 per cent of global emissions, and falling. Even if Britain stopped using energy altogether, global temperature by 2035 would be six thousandths of a degree C less than if we carried on as usual. If we shut down once a week on Planet Day, make that less than one thousandth of a degree. Even if every Western country complied with Kyoto (and most won't), Senator James Inhofe of Oklahoma says temperature a century from now would be a 25th of a degree lower than without Kyoto.