Otequay of the Ayday
"And since 1979, an entire climate industry has grown up that has spent millions of human-hours applying that constantly increasing computer horsepower to studying the climate.
And after the millions of hours of human effort, after the millions and millions of dollars gone into research, after all of those million-fold increases in computer speed and size, and after the phenomenal increase in model sophistication and detail ... the guesstimated range of climate sensitivity hasn't narrowed in any significant fashion. It's still right around 3 ± 1.5°C per double of CO2, just like it was in 1979." --Willis Eschenbach
In the linked article Eschenbach, a self-described amateur scientist and generalist, gives an overview of climate science since its beginnings circa 1979. Click continue reading for the discussion of computing power that preceeds this quote, and click on the first link to find in his conclusion the real reason for lack of progress. Hint: Check your premises.
So there you have it, folks. The climate sensitivity is 3°C per doubling of CO2, with an error of about ± 1.5°C. Net feedback is positive, although we don’t understand the clouds. The models are not yet able to simulate regional climates. No surprises in any of that. It’s just what you’d expect a NAS panel to say.
Deleterious Anthropogenic Warming of the Globe
Quote of the Day
Posted by JohnGalt at March 8, 2012 2:48 PM
Now, before going forwards, since the NAS report is based on computer models, let me take a slight diversion to list a few facts about computers, which are a long-time fascination of mine. As long as I can remember, I wanted a computer of my own. When I was a little kid I dreamed about having one. I speak a half dozen computer languages reasonably well, and there are more that I’ve forgotten. I wrote my first computer program in 1963.
Watching the changes in computer power has been astounding. In 1979, the fastest computer in the world was the Cray-1 supercomputer. In 1979, a Cray-1 supercomputer, a machine far beyond anything that most scientists might have dreamed of having, had 8 Mb of memory, 10 Gb of hard disk space, and ran at 100 MFLOPS (million floating point operations per second). The computer I’m writing this on has a thousand times the memory, fifty times the disk space, and two hundred times the speed of the Cray-1.
And that’s just my desktop computer. The new NASA climate supercomputer “Gaea” shown in Figure 1 runs two and a half million times as fast as a Cray-1. This means that a one-day run on “Gaea” would take a Cray-1 about seven thousand years to complete …
Now, why is the speed of a Cray-1 computer relevant to the NAS report I quoted from above?
It is relevant because as some of you may have realized, the NAS report I quoted from above is called the “Charney Report“. As far as I know, it was the first official National Academy of Science statement on the CO2 question. And when I said it was a “recent report”, I was thinking about it in historical terms. It was published in 1979.
Here’s the bizarre part, the elephant in the climate science room. The Charney Report could have been written yesterday. AGW supporters are still making exactly the same claims, as if no time had passed at all. For example, AGW supporters are still saying the same thing about the clouds now as they were back in 1979—they admit they don’t understand them, that it’s the biggest problem in the models, but all the same but they’re sure the net feedback is positive. I’m not sure clear that works, but it’s been that way since 1979.
That’s the oddity to me—when you read the Charney Report, it is obvious that almost nothing of significance has changed in the field since 1979. There have been no scientific breakthroughs, no new deep understandings. People are still making the same claims about climate sensitivity, with almost no change in the huge error limits. The range still varies by a factor of three, from about 1.5 to about 4.5°C per doubling of CO2.
Meanwhile, the computer horsepower has increased beyond anyone’s wildest expectations. The size of the climate models has done the same. The climate models of 1979 were thousands of lines of code. The modern models are more like millions of lines of code. Back then it was atmosphere only models with a few layers and large gridcells. Now we have fully coupled ocean-atmosphere-cryosphere-biosphere-lithosphere models, with much smaller gridcells and dozens of both oceanic and atmospheric layers.