In some followup discussion with Barry Bickmore (by email) and Kevin C (at Skeptical Science) it became clear we were missing something in the analysis of Roy Spencer's climate model. Specifically, Bickmore's Figure 10:
differed significantly from Spencer's 20th century fit even though he was ostensibly using the same parameters. If you look at the year 1900 in particular, Bickmore's Figure 10 has a temperature anomaly slightly above zero, while Spencer's is pegged at -0.6 C. Bickmore did use a slightly different PDO index than Spencer for his 1000-year graph (figure 10) - but more importantly, he took Spencer's -0.6 C temperature as the starting point in the year 993 AD, rather than as a constraint on temperature in the year 1900, as it actually was in Spencer's analysis. It turns out that to actually match Spencer's 20th century temperature fit the starting temperature in 993 AD needs to be extraordinarily, far beyond impossibly, low. We'll get to the details shortly.
BYU geologist Barry Bickmore recently reviewed Roy Spencer's recent book, "The Great Global Warming Blunder", finding a number of true "blunders" by the author. In particular he found some very peculiar properties of the simplified physical model that Spencer made a central feature of the book, finding that Spencer's curve-fitting allow infinitely more solutions than the one Spencer somehow settled on, and a number of related issues.
I tangled with Spencer over an earlier model like this which he was promoting more than 3 years ago. What he didn't seem to realize about that first model was that it was essentially trivial, a linear two-box model with two time constants (a subject I explored in detail here a while back). I tried explaining this, but he seems not to have gotten my point that such a model inherently contains no interesting internal dynamics, just relaxation on some (in this case two) time scales. Which seems to go completely against the point I thought he was trying to make, that some sort of internal variability was responsible for decadal climate change.
So it was something of a surprise to me that Spencer based his "Great Blunder" book on an even more simplified version of this model, with just 1 effective time constant. He even tried to get a paper published using this essentially trivial model of Earth's climate. As Bickmore outlined in his part 1, the basic equation Spencer uses is:
(1) dT/dt = (Forcing(t) – Feedback(t))/Cp
where T is the temperature at a given time t, Forcing is a term representing the input of energy into the climate system (there is a standard definition for this in terms of radiation at the "top of the atmosphere") and Feedback is a term that itself depends on temperature as
(2) Feedback(t) = α (T(t) - Te)
with α a linear feedback parameter and Te an equilibrium temperature in the absence of forcing (Bickmore and apparently Spencer don't actually use absolute temperature T and equilibrium value Te, but rather write the equations in terms of the difference Δ T = T - Te, which amounts to the same thing, but obscures an important point we'll return to later).
The final term Cp is the total heat capacity involved. Each of forcing, feedback and heat capacity is potentially a global average, but would normally be expressed as a quantity per unit area, for example per square meter. Since the bulk of Earth's surface heat capacity that would respond to energy flux changes on a time-scale of a few years is embodied in the oceans (about 70% of the surface), Cp should be defined essentially as 0.7 times the heat capacity of water per cubic meter, multiplied by the relevant ocean depth in meters (h):
(3) Cp = 0.7*4.19*10^6 J/(m^3 K) * h = c * h
where c = 2.9 MJ/(m^3 K) (Spencer and Bickmore seem to have forgotten the factor of 0.7, so use a slightly larger value for c, which means their h values are probably smaller than the actual ocean depth such a heat capacity would be associated with).
Since becoming a Viscount in June 2006, Christopher Monckton seems to have transformed into a climate crusader, with "Lord Monckton" heralded by conservative politicians and demagogues from Canada to Australia, even recently by the Tea Party here in the US. His first official foray seems to have been this November 2006 article in the UK Daily Telegraph, full of his characteristic pseudo-science, quickly shown to be wrong in almost every respect. July 2008 saw his "Physics and Society" article, again full of nonsense, prompting myself among many others to put some effort into showing the many things he had gotten wrong. I also responded with a shorter and more formal article to the newsletter, copying Monckton as a courtesy, a kindness which he and his associates promptly abused.
In general, Monckton's pronouncements on climate have been so ridiculous that no climate scientist or other prominent member of the climate community has wanted to even appear with him to lend him any credibility. However, this past February Tim Lambert of the Deltoid blog finally agreed to a debate - note Lambert is a computer scientist whose interest in climate is personal, not associated with his work. The resulting discussion was quite respectful - the full debate is viewable here on YouTube - and despite the Monckton-friendly audience and moderator showed Monckton exactly for the pompous clown he has become.
Now Peter Sinclair (greenman3610) has put together two brilliant video debunkings of Monckton's fantasies on YouTube, the second featuring Lambert and a great set of quotes from Margaret Thatcher, who Monckton proudly claims to have worked for in the 1980s: