Anthropogenic Global Warming: Who put the hype in hypothesis?

A blog by Peter Foster in the National Post (Full Comment) caught my eye this week. I have studied and taught science for more than 35 years so I am well familiar with the Scientific Method and how it is used. Mr. Foster's comments on Anthropogenic Global Warming (AGW) pretty much says it all for me.
I have no doubt that Global Warming is occurring or has occurred, otherwise I'd be writing this from under at least 1000 metres of ice that passed through these parts during the last Ice Age. The ice is gone, so it must have melted because of rising temperatures whose cause has yet to be determined, but it wasn't us. In fact the melting continues and has now reached Canada's most northern outposts including Arctic waters. As well, glaciers and ice sheets around the world seem to be shrinking, and yes it is possible that certain gases released by human activity have accelerated this melting; that is the hypothesis that underlies AGW. Make no mistake, it is still an hypothesis. In science an hypothesis is not a fact or even a theory. To use an hypothesis to make predictions, extrapolate consequences or anything else is bad science and of course that is the basis of the general belief that AGW will lead to global catastrophe. A tenuous cause predicts catastrophic events that are accepted by a consensus of scientists and politicians. The effect is accepted before the cause is proven. Why governments and many scientists have acceded to this idea with apparently little dissension is discussed in Mr. Foster's article but no real explanation is provided. Here is where I must show how utterly cynical I am. If you were a scientist working for the Intergovernmental Panel on Climate Change (IPCC) it is not in your self interest to question the need for your employment. If you are in government and you can expand your power to include huge amounts of money and influence it is not in your self interest to question the authority of the IPCC.

All science always operates under varying degrees of uncertainty, even the simplest weather forecast is couched in terms of probability of this or that happening. Weather prediction is a science because as more data is gathered the degree of uncertainty is diminished and weather events can be predicted with reasonable accuracy in the short term. Climate prediction is very different. Although our computer climate models show temperature increases in the future with potentially catastrophic effects, the models and the very computers themselves are so new that the accuracy of their predictions is questionable at best compared to currently used weather models. With that level of certainty is it wise to spend billions or more to mitigate a situation that may not happen? Then why do it? Self interest - but not yours.