Though you wouldn’t know it from the antagonistic nature of public discussions about global warming, a large measure of scientific agreement and shared interpretation exists amongst nearly all scientists who consider the issue. The common ground, much of which was traversed by Dr. Hayhoe in her article, includes:
· that climate has always changed and always will,
· that carbon dioxide is a greenhouse gas and warms the lower atmosphere,
· that human emissions are accumulating in the atmosphere,
· that a global warming of around 0.5OC occurred in the 20th century, but
· that global warming has ceased over the last 15 years.
The scientific argument over DAGW is therefore about none of these things. Rather, it is almost entirely about three other, albeit related, issues. They are:
· the amount of net warming that is, or will be, produced by human-related emissions,
· whether any actual evidence exists for dangerous warming of human causation over the last 50 years, and
· whether the IPCC’s computer models can provide accurate climate predictions 100 years into the future.
Dr. Hayhoe’s answers to those questions would probably be along the line of: substantial, lots and yes. My answers would be: insignificant, none and no.
What can possibly explain such disparate responses to a largely agreed set of factual climate data?
I tend to the latter view. As I’ve noted in the past, I have zero confidence in the predictive power of existing climate models, for very good reason.