Ted, the 'Mass Dieback' Viridian message also discusses the concept of 'abrupt climate change' and the probability that it will trigger an ice age. The effects are related. It's also true that climate change is inconsistent around the globe, though the 'global warming' term is accurate for average climate. The environmental scientists I've read or spoken with personally have no question that human activity has accelerated warming trends. The result of this acceleration is less certain, but mitigation is overall a Good Thing. I think the "large political components" are in the suppression of evidence that mitigation is necessary, where mitigation might have an adverse impact on many, if not most, industries. I don't see much hysteria - denial is more common.