Written by ICECAP
By Paul Biggs on Jennifer Marohasy Politics and Environment Blog
A new paper by Demetris Koutsoyiannis et al has been published, which demonstrates that climate models have no predictive value. The full paper entitled, ‘On the Credibility of Climate Predictions' is published in the Journal of Hydrological Sciences, and is available for free download. 18 years of climate model predictions for temperature and precipitation at 8 locations worldwide were evaluated
The Abstract states: "Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported." See post and blog comments here.
As one poster noted : "On a more salient point; this paper by Koutsoyiannis looks to be a polished up version of this one which surfaced in May.I have been banging on about it for some time, and it doesn't seem to have got much reaction at the usual AGW websites." Another poster responded "Serious contradictory evidence is usually met with silence at the usual AGW sites for a simple reason - if it isn't discussed, it cannot therefore exist."
Also on the blog is a link to this presentation by Ian Wilson "Which Came First, the Chicken or the Egg" unrelated to models but having to do with planetary movements and their effect on the center of mass of the solar system which he shows may influence the solar cycles and the PDO and NAO.