It’s a slippery slope. Once you look into what is being proposed as contrary science, it’s hard to avoid Pielke-land.
This starts with the infamous “hot spot” controversy, which I’ve seen described as a “holy grail” by denialists but which I had little idea about. So I started out trying to make sense of the Klotzbach paper referenced by d’Aleo
. Well, I got sort of befuddled in the middle, but RP Jr has piped up, with a very strong informal blog claim that the paper constitutes “Evidence that Global Temperature Trends have been Overstated
” which is somewhat more readable, but still confusing.
This in turn refers us to RP Sr, “Why there is a Warm Bias in the Existing Analyses of the Global Average Surface Temperature
” which looks like fairly straightforward boundary layer talks. But it starts right out with a reference to a peer reviewed Matsui and Pielke 2005: “Should light wind and windy nights have the same temperature trends at individual levels even if the boundary layer averaged heat content change is the same?”
Again, a paper that seems to flicker in and out of comprehensibility for me.
But this last paper refers to Eastman et al 2001, claiming that
As shown, for example, by Eastman et al.  the addition of carbon dioxide to the atmosphere alters the downwelling long-wave radiative fluxes such that, in their idealized sensitivity experiments, the nighttime minimum temperature was increased, although the daytime maximum (and thus the temperature above the surface in the ‘‘residual layer’’ was essentially unchanged).
So we are basing an argument on this Eastman result. Yet, in the same paragraph 17 in M&P, we have
In the results reported in Eastman et al., a doubling of the carbon dioxide concentrations in the model resulted in a growing season, central Great Plains area-averaged increase of minimum temperature about 0.1 C.
Doubling of CO2 leads to an average temperature increase of only 0.1 C ? OK, I’m trying to be patient, but now my BS detector is ringing pretty loud. Surely this is a typo? I mean, if the whole argument is based on a sensitivity 30 times lower than commonly believed, doesn’t it become a circular argument? If everything we know is wrong, then we don’t even know anything!
So what is this Eastman paper? Why it’s Eastman, J. L., M. B. Coughenour, and R. A. Pielke (2001), “The effects of CO2 and landscape change using a coupled plant and meteorological model, Global Change Biol., 7, 797– 815.” Not a single paper in this chain of reasoning outside of the Pielke domain.
Now what is this odd paper, which overthrows all of climate science, yet is published in a biology journal? It’s a (wait for it) model study.
What’s worse, it is a completely wrongheaded model study. It attempts to get a CO2 sensitivity from a limited area model run over a 14 degree lat x 14 degree lon domain. What’s wrong with this picture? (Aside from the fact that its radiation model is the admittedly “rather simple” model of Mahrer & Pielke 1977
?) Well the radiative equilibration time of the atmosphere is long compared to the residence of an air particle in a 14 degree lat/lon box. So how the hell are you supposed to set up the boundary conditions? Surely not from observations? That would pretty much, er prevent any warming from happening at all, right?
In order to simulate the 1989 growing season, the model uses a Newtonian relaxation method at the outer 3 grid points of the domain. Newtonian relaxation adds a tendency term to the prognosed quantity that drives it towards the observations from the NCEP reanalysis product (Kalnay et al. 1996).
Not just the boundaries but the outer 3 grid points are dragged back toward observation at every time step on a 26 x 30 domain. That’s 38% of the whole domain. Look. This is an experiment guaranteed to do about as close to absolutely nothing as possible. And guess what? It doesn’t do anything!!!
Note that we have a chain, Klotzbach Pielke Pielke Christy & McNider 2009 to Matsui & Pielke 2005 to Eastman Coghenour & Pielke 2001 to Mahrer & Pielke 1977.
You can’t fool me Mr. Feynmann. It’s Pielke’s all the way down.
The thing is, the Eastman piece, which seems like it might be crucial to the whole thing, is close enough to what I know that it’s not a slog for me to get through it. And that piece is, err, what can I say, obviously wrong. A huge computational effort based on negligible computational skill. (No wonder these people don’t trust models!)
(What of Mahrer & Pielke? Amazingly, Google scholar finds a copy. If I read it correctly, here is the actual radiation model used:
That’s the whole thing. I doubt that is much good if radiation at the surface is actually the issue as in the present application. So the radiation model is likely inappropriate, but there’s no great need to think deeply about it. It’s moot.
There are reasons we don’t use limited area models in climate studies of this kind. The Eastman result is already badly wrong.
So what are we to make of the whole enterprise? How much does Klotzbach Pielke et al depend on Eastman Pielke et al, and how much similarly confused reasoning is there in the whole stack?
Update: Roger Pielke Jr suggests in comments that
[I, mt] have badly confused “downwelling long-wave radiative fluxes” with the concept of “climate sensitivity.” The first has to do with boundary layer meteorology and the latter with the equilibrium consequences of radiative forcing. These are completely separate effects of an increase in CO2 and yet you have mistakenly conflated them in order to try to discredit this paper
It is in fact very difficult for me to imagine myself conflating “downwelling long-wave radiative fluxes” with the concept of “climate sensitivity.”
These are concepts I deal with every day, and they aren’t even remotely alike. I would call the IR flux an energy density in watts per square meter, mapped to space (not just the boundary layer, of course). I would call the climate sensitivity, a global scalar, degrees C per (unit forcing), most often CO2 equivalent. I’d be interested to see where I might have confused them.
This seems like it itself must be a misunderstanding of something I was saying. I don’t see how I could have conflated them. Like chop suey and donut holes, there is some very broad category relationship in my mental map, (foods associated with cheap restaurants, quantities associated with planetary physics) but the possibility of confusion is very small.
Note: RP Jr. also asserts that Klotzbach et al is not dependent on Eastman et al. by way of Matsui and Pielke, and that the relationship should be counted as minor supporting evidence.