Reader Jeff Glassman of rocketscientistsjournal.com left a comment about Murry Salby, which regrettably got held up in the spam filter. Because he devoted much time to writing it, I’ve upgraded his comment to a post.
On 4/18/2013, Ferdinand Engelbeen misunderstands Henry’s Law and its dominance over atmospheric CO2 to the exclusion of human emissions.
1. Neither Salby nor the IPCC refers to the solubility of CO2 in water, or to Henry’s Law. In trying to rehabilitate the Revelle Factor for AR4, an IPCC author showed that it was temperature dependent, and as can be seen, resembling Henry’s coefficient for CO2 in water. Expert reviewer Nicolas Gruber explained that this dependence was a “common misconception”. Thereupon the IPCC editor deleted the figure for the final report “in order not to confuse the reader”, supposedly with uncomfortable solubility effects. Cf. Second Order Draft, Fig. 7.3.10(a)) and AR4, Fig. 7.11.
2. While laboratory values for Henry’s coefficients require approximating thermodynamic equilibrium, Henry’s Law does not predict thermodynamic equilibrium, and its coefficients must therefore be used advisedly. Neither climate, the ocean, the surface layer, nor Earth’s primary heat source, the Sun, is ever in thermodynamic equilibrium. IPCC and Salby refer to equilibrium, which is false if they mean thermodynamic equilibrium, and otherwise they supply no definition for their peculiar meaning of equilibrium.
3. Henry’s Coefficient for CO2, g/100g, varies by a factor of over 5 (0.06 to 3.3) with temperature of the solvent, water. This is a constant of proportionality for the dissolution of CO2 caused by its partial pressure. So the ocean uptakes more CO2 as the partial pressure of CO2 increases or as ocean temperature drops. Applying Henry’s Law with respect to air temperature, without more, is an error.
4. In the Vostok record, however, air temperature and CO2 records vary according to Henry’s Law, and certainly with no human contribution. Vostok air temperature deduced from oxygen and deuterium fractions appears to provide a proxy for sea temperature, too. The Law remains as applicable today for forecasting atmospheric CO2.
5. The peak-to-peak variation of CO2 at Vostok is about 120 ppmv, while the similar variation for air temperature there is about 12K, yielding a sensitivity of about 10 ppmv/K.
6. As Salby rediscovered, paleo CO2 lags temperature with a peak at about one millennium. He does not mention having investigated a cause for the lag. Regardless, comparing CO2 and air or sea temperature with data over the industrial era or over any common period is irrelevant. Measured CO2 is a result of ocean temperature changes from centuries past.
7. The dominant observed lag in CO2 with respect to air temperature and possibly water temperature is about the same as the estimate for the period of the Meridional Overturning Circulation. This current, also known as the Great Conveyor Belt, draws nearly freezing water at the poles, saturated in CO2, down to the ocean bottom, around the globe and up to the surface at the Eastern Equatorial Pacific about a millennium later. There old waters, still saturated in CO2, warm to tropical temperatures to outgas. Now depleted, the old waters circulate poleward across the surface, cooling to recharge with CO2 along the way. This submodel accounting for the lag reinforces the model from the curved correlation between CO2 and temperature at Vostok. The conclusion is that atmospheric CO2 follows from Henry’s Law applied to the ocean.
8. Natural CO2 fluxes today are SWAGs, good to maybe one significant figure. The fluxes are about 91 GtC/yr from the ocean, 120 GtC/yr from land (Salby used an obsolete value half as big), and another 270 GtC/yr from leaf water, a parameter that IPCC estimated but never applied. Man’s emission of CO2 is a tiny number lost in the noise of the other fluxes, worse than Salby suggests. IPCC’s models, the GCMs, are small-signal simulations where the natural world is falsely presumed to have a zero net effect.
9. Selby also re-discovered that ice core data underestimate atmospheric CO2, in particularly that from the Keeling Curve. That curve is a heavily filtered, reconstituted record for MLO, the “master time series”, a reference IPCC experts use to calibrate other stations into a false global agreement. This makes MLO data appear global, makes atmospheric CO2 therefore long-lived, and so causes anthropogenic CO2 to accumulate in the atmosphere for maximum effect. CO2 is fixed in the ice core once the firn closes, and this may require between 600 and 2000 years maximum (estimates vary). Also Vostok samples have an average period of about 1500 years. So the Vostok samples are averages over as much as 600 to 2000 years, and the chances of even sampling an event like the 50 year long Keeling Curve is about one in 30. And even if it happened to be sampled, it would be lost in the noise due to the extended aperture time. By contrast, Keeling samples have a window of at most one minute in the manual mode, and normally much less. The long aperture time causes an indelible loss in information.
10. Like IPCC, Salby relies on data from ice cores that blend smoothly into the instrument record in the same chart. See “Evolution during the 20th Century”, 4/18/2013, time 34:08; and AR4, Summary for Policymakers, Figure SPM.1. In these charts, the underestimation by ice cores has vanished, contradicting both Salby’s model and the actual cause: ice core data is a low pass filter with a time constant of about half a millennium. The graph is but another example of IPCC’s chartjunk.
11. Salby’s conclusion is correct that human emissions are insignificant in the concentration of CO2 in the atmosphere. The observed record is natural.