But what if there is global warming and you did nothing?
The so called "Precautionary Principle" can be far more destructive than doing nothing. Suppose that the Holocene (present inter-glacial) ends and we have made no preparations for it because we have assumed global warming then mankind is going to be really in a bind. As it is there are estimates that as many as 7,000 additional winter deaths in the UK alone were attributable to the high cost of fuel caused in part by subsidies to "re-newables "
A classic example of the unintended consequences of the "Precautionary Principle" is D.D.T. Its use was banned and conservative estimates are that hundreds of thousands in Africa and Asia have died from diseases carried by insect vectors.