All Scientists are Sceptics ~Professor Bob Carter

Whenever someone asserts that a scientific question is “settled,” they tell me immediately that they don’t understand the first thing about science. Science is never settled. Dr David Deming

Perhaps the most frustrating aspect of the science of climate change is the lack of any real substance in attempts to justify the hypothesis ~Professor Stewart Franks

A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf
A lie told often enough becomes the truth.
-- Vladimir Ilyich Lenin - See more at: http://thepeoplescube.com/lenin/lenin-s-own-20-monster-quotes-t185.html#sthash.aTrSI3tG.dpuf

Wednesday, 4 December 2013

New Paper: Global Climate Models Questionable

A new paper in Energy & Environment 24 -  by Dr Nicola Scafetta (pdf here)
SOLAR AND PLANETARY OSCILLATION CONTROL ON
CLIMATE CHANGE: HIND-CAST, FORECAST AND A
COMPARISON WITH THE CMIP5 GCMS



Abstract

Global surface temperature records (e.g. HadCRUT4) since 1850 are characterized by climatic oscillations synchronous with specific solar, planetary and lunar harmonics superimposed on a background warming modulation. The latter is related to a long millennial solar oscillation and to changes in the chemical composition of the atmosphere (e.g. aerosol and greenhouse gases). However, current general circulation climate models, e.g. the CMIP5 GCMs, to be used in the AR5 IPCC Report in 2013, fail to reconstruct the observed climatic oscillations. As an alternate, an empirical model is proposed that uses: (1) a specific set of decadal, multidecadal, secular and millennial astronomic harmonics to simulate the observed climatic oscillations; (2) a 0.45 attenuation of the GCM ensemble mean simulations to model the anthropogenic and volcano forcing effects. The proposed empirical model outperforms the GCMs by better hind-casting the observed 1850-2012 climatic patterns. It is found that: (1) about 50-60% of the warming observed since 1850 and since 1970 was induced by natural oscillations likely resulting from harmonic astronomical forcings that are not yet included in the GCMs; (2) a 2000-2040 approximately steady projected temperature; (3) a 2000-2100 projected warming ranging between 0.3 °C and 1.6 °C, which is significantly lower than the IPCC GCM ensemble mean projected warming of 1.1 °C to 4.1 °C; (4) an equilibrium climate sensitivity to CO2 doubling centered in 1.35 °C and varying between 0.9 °C and 2.0 °C.

Reviewed by CO2 Science (link)

Background
The author writes that "global surface temperature records (e.g. HadCRUT4) since 1850 are characterized by climatic oscillations synchronous with specific solar, planetary and lunar harmonics superimposed on a background warming modulation," which he says "is related to a long millennial solar oscillation and to changes in the chemical composition of the atmosphere (e.g. aerosol and greenhouse gases)." However, he notes that "current general circulation climate models, e.g. the CMIP5 GCMs, to be used in the AR5 IPCC Report in 2013, fail to reconstruct the observed climatic oscillations."

What was learned
Scafetta reports that his proposed empirical model "outperforms the GCMs by better hind-casting the observed 1850-2012 climatic patterns." More specifically, he notes that "about 50-60% of the warming observed since 1850 and since 1970 was induced by natural oscillations likely resulting from harmonic astronomical forcings that are not yet included in the GCMs."

What it means
The way Scafetta sees things, "the results of this analysis indicate that the GCMs do not yet include important physical mechanisms associated with natural oscillations of the climate system." And, therefore, he suggests that interpretations and predictions of climate change based on current GCMs, including the CMIP5 GCMs to be used in the IPCC AR5, are "questionable."

Read More at CO2 Science.

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