Considering that climate models are predicting global temperatures to be rising at a rate far greater than they actually are, you would think that the model developers would be taking a long, hard look at their models to try to figure out why they are on the verge of failing.
In fact, I would expect to soon start to see papers in the scientific literature from various modeling groups attempting to explain why their models have gone awry and to provide an accompanying downward revision of their projections of 21st century temperature change. After all, how long a period of no warming can be tolerated before the forecasts of the total warming by century’s end have to be lowered? We’re already into our ninth year of the 100 year forecast period and we have no global warming to speak of (Figure 1).…
Just how much warming should we expect from rising levels of atmospheric greenhouse gases (GHGs)? The answer largely hinges on how much extra warming might be generated by the initial warming—that is, how strong (and in what direction) are the feedbacks from water vapor and clouds.
By most estimates (including climate model outcomes), these feedbacks are positive and result in about a doubling of the warming that would result from greenhouse gas increases alone. By others, however, the total feedbacks are negative,…