The central point Trenberth makes about GCM predictive reliability is this one, “The current projection method works to the extent it does because it utilizes differences from one time to another and the main model bias and systematic errors are thereby subtracted out. This assumes linearity.”
What he’s saying is that one can reliably project future forced global temperature differences because in subtracting forced GCM runs from control GCM runs all the errors subtract away, leaving a reliable trend in anomalies.
But this is assuming much more than mere “linearity.” It assumes the GCMs procduce global climate projections with completely accurate slopes. Trenberth is claiming that GCM runs are only linearly offset by some standard vertical magnitude from being fully correct — and the same standard vertical magnitude is present in both control runs and forcing runs. Therefore, subtracting the latter from the former produces accurate anomalies.
But this is very different from assuming mere linearity. It supposes that the physical representation of the global climate itself — the physical theory in the GCMs — is complete and accurate. The errors are merely from imperfect measurements and a too-coarse resolution because of computer limitations. This assumption — assertion, really — is entirely unjustifiable.
For example, all GCMs include a hyperviscosity because the Navier-Stokes equations can’t be solved at all the necessary levels of resolution. The hyperviscosity, which is completely unphysical, is the only thing that makes the GCMs integrable — they would catastrophically diverge otherwise. Because there is an unphysical hyperviscosity, the parameterizations in GCMs must also be unphysical in order to compensate. Consequently, GCMs inherently cannot be physically correct. Trenberth’s claim includes an implicit but absolutely central assertion that cannot be true. The physical theory in GCMs is neither correct nor complete. Trenberth is wrong, the reliability of temperature predictions can not be claimed accurate through taking differences, and the whole of AGW so-called science is powered by this sort of tendentious delusionalism.
When you check to see daily max and mins for a range of Northern NT stations,
(scroll down past the green rainfall data to the pink and blue max and min temperature data). You find that this heat wave was pretty much a one day wonder in many places, a couple of days in some.
Further down the page I note how the BoM show bias towards reporting warming events by not putting out a media release about the stunning cold record day 20 June 2007 etc as recorded at Tennant Creek and many other places on 19th, 20th and 21st June 2007 across the continent from Halls creek to SW Qld, to NW NSW. Continue reading Warming bias in media releases from the Australian Bureau of Meteorology (BoM)→
I have several Blog posts drawing attention to David’s important prediction that Solar Cycle 24 would be delayed, shorter than other major climate groups (NASA, NOAA) were saying and could in his opinion lead to a cooling climate.
Solar Cycle 23 not ending yet
July 6th, 2007 Download a PowerPoint presentation of David Archibald’s latest edit of his paper, “The Past and Future of Climate” presented at the Lavoisier Conference in Melbourne June 2007.
The small coral atoll Willis Island (16.3 South, 150 East) is the site of a weather station in the Coral Sea just over 400 kms easterly from Cairns, north Queensland, Australia.
At a time of national green media driven near hysteria over “global warming” and widely accepted claims that the Great Barrier Reef (GBR) is threatened by “global warming”, it seems odd in this modern day and age that highly relevant temperature data can not be successfully recorded.
Why has Willis Island temperature data deteriorated to such an extent as to now be useless ?
Below is the monthly mean data from NASA GISS from 1992 the year with the first missing month Continue reading Marked deterioration in Willis Island temperature data quality→
On the night of the Australian Federal Election 24 November 2007 Treasurer Elect Wayne Swan was heard to say on Channel 9 TV that the swing to the ALP in electorates along the Queensland coast was due in part to “global warming threatening the Great Barrier Reef (GBR)”.
Here is the temperature trend for Willis Island, site of a weather station in the Coral Sea just over 400 kms easterly from Cairns. The Liberal Senator Helen Coonan tried bravely to swim against the tide and hinted at complex scientific issues that had to be understood but her effort was swept aside.
Does anyone seriously think the GBR could be “threatened by global warming”, when the Willis island data shows no trend since WWII ?
How do such fairy stories pass as fact and become part of national mass belief ?
Primarily exposing faulty methodologies behind global temperature trend compilations