Dr. Salby at a GWPF Lecture
Dr. Murry Salby has been getting substantial attention in the climate blogosphere, for two reasons. First is his theory that at least 2/3 of the observed increase in atmospheric CO2 is natural and temperature induced. Second are the circumstances surrounding his departure from U. Colorado and later termination from Macquarie University. This post covers the first and not the second, and is motivated by a very recent WUWT post on the mysteries of OCO-2, where the Salby theory was raised yet again in comments.
Dr. Salby developed a substantial scientific reputation for work on upper atmosphere wave propagation and stratospheric ozone. He has published two textbooks, Atmospheric Physics (1996) and Physics of the Atmosphere and Climate (2012). His new theory that most of the increase in atmospheric CO2 is naturally temperature induced (NOT anthropogenic) is not published. He explicated it in a Hamburg lecture 18 April 2013, and a London lecture 17 March 2015. Both are available on YouTube. (Search his name to find, view, and critique them before reading on if you want to deep dive.) This post does not reproduce or critique his arguments in detail. (There are fundamental definitional, mathematical, and factual observation errors. Perhaps a more detailed companion post will follow detailing them with footnotes if this does not suffice.) This post only addresses whether his conclusions are supported by observations; it is a macro Feynman test rather than a Salby details deep dive.
Controversial CO2 Atmospheric Concentration Theory
The core of Salby’s theory is derived using CO2 data from MLO’s Keeling Curve since 1958, and satellite temperature data since 1979. (His few charts reaching back to 1880 contain acknowledged large uncertainties.) His theory builds off a simple observation, that in ‘official’ estimates of Earth’s carbon cycle budget, anthropogenic CO2 is only a small source compared to large natural sources and sinks. This is illustrated by IPCC AR4 WG1 figure 7.3.
He then deduces there must be rapidly responding temperature dependent natural CO2net sources much greater than anthropogenic sources. This is a very questionable argument on short decadal time frames. Gore got it wrong, and Salby got it wrong. The ice core based CO2 lagged change to temperature is about 800 years, common sensically corresponding to the thermohaline circulation period. (For rigorous calculations on Salby’s decadal time scales using residency half-lives and efold times, see Eschenbach’s post at http://www.wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/
He observationally bolsters his conclusion by ‘showing’ that highest CO2 concentrations are over relatively uninhabited/unindustrialized regions like the Amazon basin, so must have natural origins. The following ‘observational’ figure is from his Hamburg lecture. Except it is completely disproved by OCO-2.
As Feynman said, observation trumps theory.
First, if Salby is right, the rise in atmospheric CO2 concentrations should have slowed or stopped because of the ‘pause’. They haven’t. They bear no short or long term relationship to one another. Since 2000, CO2 has increased about 35% on the 1958 Keeling curve base; temperatures haven’t (the pause). The seasonality of the northern hemisphere terrestrial photosynthetic sink is apparent in the Keeling curve, as is the temperature/CO2discrepancy disproving Salby.
Second, satellites have NOT generally observed higher CO2 concentrations over uninhabited/ unindustrialized regions in past two decades. (The following NASA charts use AIRS IR sensors on various satellites to estimate gridded CO2 concentrations from peak CO2 OLR absorption wavelengths. The new OCO-2 data is even more stark.)
Third, Salby’s theory requires that land and/or sea serve as the temperature dependent CO2 net sources that ‘overwhelm’ anthropogenic CO2 emissions from fossil fuels and cement production. That is NOT true either; both land and sea have been serving as net sinks.
Terrestrial biomass (net primary productivity, NPP) is an increasing sink. This has been observed in multiple ways, including NASA AVHRR (1982-2009) and MODIS (2000-2009) ‘normalized difference vegetative index’ (NDVI). NDVI has been ground truthed by sampling NPP including both ‘roots and shoots’ by ecosystem. The terrestrial net biological sink has increased since 1980. It is not a source. The most recent paper is NASA’s 14% greening in 30 years, published 4/16/2016 and previously remarked at WUWT.
That leaves oceans. Biologically, oceans are a net carbon sink through photosynthesis and calcification. Satellites detect this through planktonic chlorophyll concentrations.
But there are certainly large ocean zones that are relatively barren (mainly from lack of iron fertilization in the form of dust). Those large blue barren swaths are where ocean water pCO2 and pH are monitored, precisely to minimize confounding biological sink influences recently explained on WUWT by Dr. Jim Steele. Could those also be a net source?
Barren ocean regions are mainly influenced Henry’s Law and Le Chatellier’s Principle. The first says partial pressures of ocean dissolved CO2 and atmospheric CO2 will equilibrate. The second partly says colder water stores more dissolved CO2. ARGO suggests the oceans are warming. Could Le Chatellier be stronger than Henry, in which case oceans could provide Salby’s requisite rapidly temperature dependent net natural source? There are two stations, Aloha 100 km north of Oahu (maintained by University of Hawaii and WHOI) and BATS off Bermuda (maintained by WHOI) where the hypothesis can be tested by observations. Both show even barren oceans are a net carbon sink since 1980. Barren ocean pH declines as pCO2 increases.
If there are no observational temperature dependent natural CO2 sources, and temperature dependent sinks (NH temperate terrestrial vegetation) increase with temperature, then Salby’s natural carbon dioxide theory cannot be true. It is falsified. Even before detailing his definitional, mathematical, and factual errors.
Climate Scientist Murry Salby Returns! – Presents NEW SCIENCE
Author of the seminal book on climate; “Physics of the Atmosphere & Climate” Professor Murry Salby is without doubt one of the best Climate Scientists on the planet.
In a lecture in London on the 17th March, 2015, he reveals new work which shows that;
1) The climate sensitivity is below 0.2c – confirmed by 3 independent methods.
2) Most of the observed increase in atmospheric CO2 is not anthropogenic.
3) CO2 movements and concentrations are largely determined by nature, not man; consequently, any cuts we make to our CO2 emissions will not have the desired effect, and are a costly waste of time.
4) CO2, whether man-made or not, does not ‘drive’ the climate system.
A Discussion of the Equations of Transfer
I was having an email discussion with an old professor of mine (from undergad) about the fraud of the radiative greenhouse effect who has himself implied doubt about the greenhouse effect. Actually the proff is Dr. Essex who wrote the book “Taken by Storm“. He suggested that I look at the “equations of transfer” in regard to the problem, which of course I have already done extensively and am quite familiar with. I will post the reply here since it may help some people:
“Are you still using Haberman’s “Applied Partial Differential Equations with Fourier Series and Boundary Value Problems”? We used that when I took your class in 2000.
For the flow of heat in matter we end with the diffusion equation as a function of space and time. If there is a heat source, then Q (heat) gets tacked on to the equation and Q can also be a function of space and time. The scenario with the radiative greenhouse effect is that you have matter, the ground surface, where there is basically no internal heat generation, but you do have Q at the surface boundary, i.e. at the very first element of the surface, due to sunlight.
Q of course is heat. Making this simpler than the Sun “going around” the surface location, we can just use constant values to inspect the qualitative and some quantitative features of the solution to this type of problem. To do that we must use and understand what Q is since whatever is governing Q is basically setting the boundary conditions of the problem, and the behaviour of these solutions are typically largely determined by the boundary conditions.
Q, being heat, is not simply the energy from sunlight, but is given from radiant transfer by a difference of flux values, which are of course proportional to temperature. For example in a plane-parallel model with emissivities and absorptivities all unity, then Q = Flux_hot – Flux_cool = sigma(T_hot^4 – T_cool^4), and the positive Q means that the heat is flowing to the cooler object, which would cause the cooler object to increase in temperature until Q = 0. It is simpler to use local flux when dealing with sunlight so that you don’t need to think about how the surface flux of the Sun is diluted by distance, but of course that is there.
So radiant Q is a flow given by a difference of local fluxes between two source objects. The argument of the radiative greenhouse effect from climate alarm is that Q from the atmosphere to the surface is increased by increasing greenhouse gases, therefore causing the surface to increase in temperature. Quite plainly, this argument reverses heat flow directionality since the relation between the cooler atmosphere and warmer surface (this is their general state relative to each other) is that heat, using the definition of heat, flows from the warmer surface to the cooler atmosphere. They call their heat-reversal mechanism “back-radiation”, the argument being that any additional presence of radiant energy in the atmosphere will cause temperature increase on the surface; this conflates energy for heat, because energy is not always heat and can only manifest or act as heat when flowing from warm to cool, causing the cool to increase in temperature.
Q between the Earth’s surface and Earth’s atmosphere is positive, meaning that heat is flowing from the warmer surface to the cooler atmosphere. Their other argument attempting to explain the mechanism of “back-radiation” is that making Q less positive will increase the temperature of the warmer surface. This is a complete fabrication and pseudoscience of thermodynamics, and here is where their argument reduces to Zeno’s Paradox. Q is supposed to become less positive, in fact it is supposed to go to zero, but if in doing so this increased the temperature of the warmer object, then this would also increase the temperature of the cooler object, and then you effectively have Zeno’s Paradox or a variation on it (you never reach the end because the finish line of Q = 0 is itself running away from you). What they are doing is treating Q as a conserved, constant quantity, which of course heat isn’t, and typically denote heat as given by the energy from sunlight, which is of course not Q (heat) in the first place given that Q is a difference of source fluxes, not a source flux in and of itself.”