Our engineering college once got a lawyer to give a talk to our class. He said engineers and scientists make the worst expert witnesses because they always unwittingly defeat themselves by admitting to reasonable doubt. It's within a scientist's nature to have doubt, so this may be why science doesn't make political policy until it is(?) too late.

I remember first reading about global warming in the late 80's-early 90's. The articles would almost sound apologetic about how much assumptions went into their climate models, how undeveloped the models are, and so on. I didn't think much about global warming either, because it didn't sound urgent or sure of itself.