unfortunately our detractors, those looooking to sort of polle the public discoursrse on mattes of s science like global w warmg are more than happypy to state their opinions with absosolute certainty. so it's important to understand t that there is sortf an asymmetry i in the battle ovr informing the public about science. we're at a bit o of a disadvantage a as scientisists becaususe we have to be true to our principles. we have to be honest. and we have to recognize nd describe things in rms of caveats, in terms of layers of uncertainty. there are no absolutes. that having been said, it's perfectly appropriate fofor a climate scientist to say we are nearly certain that the globe is warming because of us, because of increased greenhouse gas concentrations from fossil fuel burning and other human activities, and if we continue on the course that we're on, we are likely to see very y damagig impacts on us, on our environment. one of the valid, in my view, criticisms of the ipcc is t that in many respects it has been overly conservative in the way it has stated its conclusions, and the