I liked this a lot. But, having said that: the short write up glosses on the net present value vs investment outcome decision. Its a strong sell to the precautionary principle but without discussing the downside consequences for long-term rates of return if speculation is damped out (for instance) from an excess of precautions. I might add AGW stands as a bloody good reason to be a lot more cautious about future costs and risks of 'business as usual' decision making