The 3rd piece of AGW news of note comes from Professor Steven Sherwood from the University of NSW Climate Change Research Centre. Sherwood's new paper concludes that things are worse than we thought because climate sensitivity, the temperature reaction of the climate system to AGW, is actually higher.
Sherwood reaches this conclusion by looking at which of his climate models were best at modelling and predicting the mixing rate of clouds and water in the lower atmosphere. Sherwood found that those models which predicted the highest temperatures were best at predicting the mixing rates.
The fallacy of this conclusion has several ingredients. Firstly even Sherwood concedes that knowledge of clouds is lacking and is responsible for most of the uncertainty with AGW predictions. How clouds form and effect climate depends on much more than the mixing rates in the lower atmosphere.
Just because Sherwood's warming models can model one aspect of cloud behaviour doesn't mean they model well any other aspect of clouds or climate. For instance In a critique of Sherwood's study Michaels and Knappenberger note that Sherwood's models which predicted mixing best were worst at predicting temperature:
Figure 1. Observed global average temperature evolution, 1951-2013, as compiled by the U.K's Hadley Center (black line), and the average temperature change projected by a collection of climate models used in the IPCC Fifth Assessment Report which have a climate sensitivity greater than 3.0°C (red line) and a collection of models with climate sensitivities less than 3.0°C (blue line) (climate model data source: Climate Explorer).
This paper by Sherwood is only the latest in a long line of papers where he has used models to prove AGW. For instance in 2008 Sherwood produced a paper proving the existence of a Tropical Hot Spot [THS], an essential prediction of AGW. In this paper, concerned that the temperature instruments showed no THS, Sherwood repudiated the instrument data and developed a windshear model which showed if there was windshear there would be warming. The irony here was that the instruments which Sherwood thought were not good enough for temperature were used by Sherwood to establish windshear and the model predicted temperature.
Sherwood's new paper received headline coverage, as did the BOM report. The ice entrapment of the Turney expedition also did but mention of the AGW purpose of the ill-fated expedition in the media was muted at best. Like the weather itself supporters of AGW run hot when the weather supports them and cold when it doesn't.
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