Many years ago I developed a simple EBM-well, actually that would be an great exaggeration of what I actually did, which was really just use a very simple functional form more or less equivalent to what I’ve been using. At any rate, I called it “Grumpy” a sort of self mocking reference to my own generally curmudgeonly persona, and also a reference to Lucia’s similar model exercise, “Lumpy” so named because it is a “lumped parameter model.” Anyway, unfortunately the work, which was kind of amateurish but meant to be a sort of sensitivity test for conclusions about model fits to the observed data, has been lost to the sands of internet time-by which I mean, Climate Audit’s forum is defunct.
At any rate, much of the work I’ve been doing since then has been with what I suppose one might call “Grumpy 2.0” which really doesn’t feature any improvements over the old version, but has been intended for uses in curve fitting exercises.
But for a bit now, I’ve been working on something. It’s not ready for prime time yet, but it’s a lot more sophisticated than my previous modeling exercises, and offers the potential for improving on the previous results significantly. Unfortunately it has many more unknowns, and I could spend an eternity searching the parameter space. At any rate, for those of you who want to see something more sophisticated than “one box” I give you Grumpy 3.0, a three box energy balance model:
Like I said, I’m not ready for prime time with this just yet. I’ve got a lot more work to do. But it’s kind of a cool project.
Now, it would be totally pointless for me to just tell you “what I’m working on” with nothing more than that. So I guess I’m also wondering if there is anyone out there interested in helping with some heavy lifting math ways and statistics ways that I’m…just a tiny bit out of my depth on? One of my current goals is to use this in conjunction with my work on volcanic eruptions to determine what combinations of parameters can be interpreted to be consistent with the data on volcanic response. But like I said, the parameter space is huge, if only because there are so many. Which might help people understand why I often say it’s a fairly trivial matter to claim anything is consistent with your preconceived notions about sensitivity. All one needs is to toy around with various parameter values. And people need to understand how many of these parameters-which are mathematical simplifications of real processes that one needs to represent reality accurately-are almost completely unconstrained, or constrained very poorly. For example, the eddy diffusion coefficient kappa, is not known to within better than an order of magnitude. As far as I can tell, the land-sea coupling constant v is even more poorly constrained. And in most cases, the function ΔQ, the radiative forcing, is largely unknown. And of course, lambda-the sensitivity-is not even claimed to be known to within better than ±50%, meanwhile the reality of the situation is probably worse than that. But at least there are ways one might constrain it’s value independently of those other uncertainties. I’ve looked into a number of such approaches, virtually all of which have given answers very close to one another and all lower than even the lowest “accepted” edge of the mainstream values. I gets someone frustrating at times. I don’t really want to be a climate extremist, being a political extremist is hard enough work. Being a lukewarmer would be a lot easier. Or at least I like to think so. I mean, I could fit in with all the cool people and not have to justify myself to literally everyone, only most people. Because I seem to occupy, If I do say so myself, the unpleasant position in the debate of being that guy who has no friends because he’s a critic of everybody. Well, okay, I’m not the only guy in that position.
But here’s my guess. Of the people who do analytical work on climate blogs I respect, I’d guess their best estimate of what the sensitivity is, is at least 3 to 4 times where I’d currently put it. So there’s a bit of a tension there that large goes unnoticed. And the part I dislike the most about this is that I think the gap is getting wider. When I first got really engaged in this debate-what has it been, like, 5 years now or something?-I would have only just barely failed to qualify as a lukewarmer. If I’m critical of the fact that mainstream sensitivity estimates are literally the same now, without even an improvement of uncertainty, as they were in the late 1970’s-and I am-I have to also be critical of myself and others-those I consider to be good analysts and largely unbiased-for failing to converge, and even diverge in our opinions. And since I’m the one whose opinion has changed, it’s concerning to consider the possibility that I am the problem.
Wow, I really kinda drifted on that one. Anyway, if you’re still reading after all that, and would like to contribute to “team Grumpy” I’ll be pleased to hear from you.