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La sensibilidad del clima

escrito por Luis I. Gómez 14 julio, 2008

Acaban de aparecer dos nuevos papers sobre el tan traído y llevado tema de la “sensitivity” del clima a los factores tenidos en cuenta por el IPCC para sus predicciones. El primero es de Christopher Monckton of Brenchley, publicado en “Physics & Society: July 2008, Volume 37, Number 3“, cuya lectura atenta les recomiendo. Les dejo con parte de las conclusiones:

Even if temperature had risen above natural variability, the recent solar Grand Maximum may have been chiefly responsible. Even if the sun were not chiefly to blame for the past half-century’s warming, the IPCC has not demonstrated that, since CO2 occupies only one-ten-thousandth part more of the atmosphere that it did in 1750, it has contributed more than a small fraction of the warming. Even if carbon dioxide were chiefly responsible for the warming that ceased in 1998 and may not resume until 2015, the distinctive, projected fingerprint of anthropogenic “greenhouse-gas” warming is entirely absent from the observed record. Even if the fingerprint were present, computer models are long proven to be inherently incapable of providing projections of the future state of the climate that are sound enough for policymaking. Even if per impossibilethe models could ever become reliable, the present paper demonstrates that it is not at all likely that the world will warm as much as the IPCC imagines.

Promete verdad? Léanlo entero!

El segundo es de Roy W. Spencer, lleva el título “Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration” y se acaba de publicar en el Journal of Climate der American Meteorological Society. También les dejo un retazo, esta vez del abstract:

For model runs producing monthly shortwave flux anomaly and temperature anomaly statistics similar to those measured by satellites, the diagnosed feedbacks have positive biases generally in the range of −0.3 to −0.8 W
m−2 K−1. These results suggest that current observational diagnoses of cloud feedback – and possibly other
feedbacks — could be significantly biased in the positive direction.

En resumen: cada vez es más fácil dudar de las previsiones sobre la influencia catastrófica de los feedbacks que nos presentaron en su día los colegas del IPCC.

Tomo, para terminar, una gráfica del trabajo de Monckton en la que se explica de qué modo han fallado las previsiones de las proyecciones hasta la fecha, motivo por el cual, las previsiones también son erróneas (y eso que seguimos aumentando la emisión de CO2!):

Global temperature projections and outturns, 1988-2020

sensitivityclima.gif

Hansen (1988) projected that global temperature would stabilize (A) if global carbon dioxide concentration were controlled from 1988 and static from 2000: otherwise temperature would rise rapidly (B-C). IPCC (1990) agreed (D). However, these projections proved well above the National Climate Data Center’s outturn (E-F), which, in contrast to the Hadley Center and UAH records (Fig. 1), show a modest rise in temperature from 1998-2007. If McKitrick (2007) (G,H) is correct that temperature since 1980 has risen at only half of the observed rate, outturn tracks Hansen’s CO2 stabilization case (A), although emissions have risen rapidly since 1988.