For something I'm working on, I'm interested to know of any contarians who predicted, circa 1975, the 0.6-0.7°C of global warming that has transpired up to now.
And why.
Lindzen, Michaels, etc? Anyone?
Or who, of today's contrarians -- Anthony Horsepower? -- would have made that prediction back in 1975? And why.
Well, as it happens, one of the sources I'd pulled regarding the pre-Mann consensus on climate (for which I claimed Hubert Lamb as the spokesman) is the supplement to the Encyclopedia Brittanica, Yearbook of Science and the Future copyright 1975, US publisher the University of Chicago, Margaret Sutton Managing Editor, with an advisory board including Louis J Battan, of the American Meteorological Society, Walter H Munk of the Institute for Geophysics and Planetary Physics at the University of California at La Jolla. The concluding pages of the article by Lamb, The Earth's Changing Climate (pgs. 180-196), taking account of various "quasi-periodic" natural processes which "all interfere with each other" neverthe less estimate what would now be called a "climate sensitivity" -- the temperature index in degrees C corresponding to a doubling in C02, of "about 1.9" which I take the liberty of rounding to 2.
ReplyDeleteGiven the concentration of CO2 in 1975 of about 330 ppm, and the current concentration of about 400 ppm, or an increase of about 20% times 2 we see Lamb forecasting the increase between then and now to be about 0.4 degrees C.
Notwithstanding his own paragraphs about CO2 Lamb also wrote, in 1975, that "it appears that at the present time natural fluctuations are still the dominant element in the Earth's climatic changes. ... The current climatic trend, which has produced a colder Artice and increased ice since about 1950, seems to have caused (on average) a slight equator-ward shift of the main zones of the global wind circulation nd the climatic belts that accompany them." (By this I infer he refers to what we lately call the polar vortex...)
ANYHOW, Lamb working with a slipstick and estimating a rise of 0.4 (vs a reality of 0.6) is doing AT LEAST AS WELL as his successors and the IPCC with their global general computerized climate models.
J Melcher: Lamb underpredicted warming since 1975 (which is 0.6 C, according to HadCRUT4).
ReplyDeleteSo we can assume he's wrong, ya? And that maybe climate modeling has progressed some in the last 40 years?
J Melcher: We haven't been at 400ppm long enough to achieve equilibrium - your claim that what Lamb wrote amounts to a prediction of 0.4 degrees C of warming by is therefore obviously and laughably wrong to anyone who has been paying attention to climate science for the last few decades. Why not just admit that in fact none of your idols back in the 1970s or 1980s could even come close to let alone match Jim Hansen's predictive accuracy circa 1981?
ReplyDeleteHi David and Jon,
ReplyDeleteWell, it's a lot easier for me to admit I might be wrong than for others, say, Michael Mann, to name one.
But the PAIR of you don't establish it. Each of you has a valid point. But if David is right, and 0.4 is unequal to 0.6, AND if Jon is right that the transient moment measurement is not the real or actual measurement, then I may still be right that Lamb circa 1975 correctly identified the momentary temperature of 2013 or so, on the way toward a final temp (assuming, nonce, and contrafactually) that CO2 in the atmosphere stabilized at 400 ppm.
We could of course ALL be wrong, but I take some pride in being the first to admit it. In this I follow the lead of other layman with an interest and a position, like, say, Mark Steyn.
Odd that Steyn and I are more willing to attempt falsification of our own hypothesis than are dogged contrarians like Mann. It's the "doggedness" that won Mann his prizes, I suppose.
Melcher's calculation is incorrect because the forcing for CO2 is logarithmic. 330 to 400 ppm is a 21% increase in CO2; 28% of the way to doubling on a log scale. 28% of a climate sensitivity of 1.9 is 0.53 degC - which is fortuitously close to 0.6 degC. And we haven't yet taken into account the additional forcing from increases in minor GHGs (minus aerosols). FInally, we weren't at equilibrium with the forcing present in 1975 and we are a little further way from equilibrium today. ECS isn't required to be at least 3.0 degC to explain recent warming.
ReplyDeleteThere wasn't a contrarian position in 1975, except possibly for those who doubted the hype about global cooling that circulated then. A more interesting question is whether anyone had the guts to predict negligible warming for the 15 years after the 1998 spike due to El Nino? The optimum time to make such a prediction would be at the time of a large spike in temperature when the cool phase of the PDO was coming. There are parallels between the local plateaus in warming beginning in 1940 and 2000 (one PDO oscillation apart) are intriguing and the 1940-1970 "pause" is harder to explain with aerosols now that the magnitude of their forcing is believed to be smaller.
J. Melcher: Mann et al's work has been replicated many times by now, some using completely independent mathematical techniques. I've put those in previous comments. Have a look if you missed them.
ReplyDeleteThanks, Frank.
ReplyDeleteJ Melcher wrote:
ReplyDeleteANYHOW, Lamb working with a slipstick and estimating a rise of 0.4 (vs a reality of 0.6) is doing AT LEAST AS WELL as his successors and the IPCC with their global general computerized climate models.
Nope. Wallace Broecker wrote a paper in 1970 that was much more accurate:
"Climatic Change: Are We on the Brink of a Pronounced Global Warming?"
Wallace S. Broecker, Science Vol. 189 no. 4201 pp. 460-463, August 8, 1975
http://blogs.ei.columbia.edu/files/2009/10/broeckerglobalwarming75.pdf
His simple prediction of warming from 1970 to 2010 was 0.81 C. The actual warming, according to Cowtan & Way's dataset, was 0.75 C.
Correction: Broecker's paper was from 1975.
ReplyDeleteAnd Broecker's number was a little high because his CO2 number for 2010, was a little high -- 403 ppm. Actually it was about 389 ppm.
ReplyDelete