by J Storrs Hall
In my previous post, I argued that sea-surface temperatures hadn’t shown an inflection in the mid-twentieth century, and that the post-50’s rise was essently a land-based phenomenon. To take the analysis further, I thought I could try to find just what the climate signal from CO2 was. The method is to find a fit to the temperature record that included the CO2 forcing signature as a component, and see how big its contribution was compared to the other components of the fit.
First, the CO2. To get a curve since 1850, I got the estimated emissions from here, integrated for accumulation, scaled by matching to the Mauna Loa measured CO2 (red), and took the log for forcing. (No arguments, please; this is the bog-standard story. Let’s assume it’s true for the sake of argument.)
There’s clearly a knee in the curve ca. 1960. Also note that it’s been essentially straight since the 70’s — it’s the log of an exponential.
For components of the fit function, I used a cosine to capture the cyclicity we already know is in the record, a quadratic, and the forcing curve. I had used a second cosine before, and we know it produced two inflections in the result. The quadratic can only produce one, so the forcing curve has a better chance of matching the other one.
The idea is to find the overall best match and then look at the components to see how big the signal from the forcing is in comparison with the other components, which we will assume represent natural variability. We’ll plot each curve with the amplitude the optimizer gives it. Here’s what we get:
The blue line is the overall fit. Cyan is the 61-year oscillation, as before. No surprises here. Magenta is the quadratic, looking a lot like the sinusoid of the previous fit. Red is the CO2 forcing.
The CO2 forcing is upside down.
I gave the optimizer an initial guess for the forcing coefficient of 1; it came back with -1.67. This was, frankly, unexpected. I had seriously thought I would find some warming contribution from the forcing component.
So what on earth is going on? Here’s what we get if we add just the quadratic and the forcing curve:
For comparison, I’ve also plotted the second sinusoid from last time (green). It seems that the secular trend that the optimizer really, really wants is the shape of a Nike swoosh. If given only a quadratic to work with, it has to subtract the forcing curve to straighten out the twentieth-century rise. And it really, really wants the knee of the curve to be in 1890.
Does this mean that CO2 is actually producing a cooling effect? Absolutely not. It simply means that the secular rise in the twentieth century was a straight line, and the fit would do whatever it took to produce that shape. (This is why Pat Frank’s linear fit worked so well. As he noted, the linearity of sea-level rise would tend to confirm this.) What it does mean, though, is that there is no discernable CO2 warming signal in the HadSST temperature record. The (very real) twentieth century warming trend appears to have started about the time Sherlock Holmes was investigating the Red-Headed League.
Pat Frank: I did show what part of the 259-year cosine took part in the fit — it’s the green curve in the third graph above: the swoosh shape. So yes, it did essentially model a straight line over the 20th century.
dwb: You can’t compare exponential growth rates for amounts with different bases. If my income is increasing at 5% per year, and I’m putting it all in the bank, that doesn’t mean that the bank’s holdings must also be increasing at 5%.
J. Simpson: It’s a question of timescale: short term, forcing induces a changing temperature; but in the long term, the system will equilibrate and take up a new stable temperature that depends on the forcing. It’s much like the accelerator in your car: press it, and you get a change in speed; but the faster you go, the air resistance increases until it matches the engine power and you level off at a new, constant, speed. It’s the standard finite impulse response curve, if you’ve ever studied control theory.
For radiative forcing and temperature, consider the difference between night and day. Temps can change tens of degrees in a few hours. If equilibration were instantaneous, the hottest part of the day would be exactly noon. Instead, it’s 2 or 3 hours later. So we’re looking at equilibration times of hours for temp changes bigger than the ones anyone is predicting from enhanced greenhouse forcing. Even if it were thousands of hours, it would still be fast enough to ignore on the scale of years.
Pat: One way to finesse the issue is simply to fit the short cosine and a quadratic to post-1910 data. Turns out that the baseline you get is very close to flat, but still slightly concave downward: I get a curve with a 0.63 degree/century slope in 1950, 0.60 in 2000. That’s SSTs with the notch taken out.
@HenryP
Your link (to your own site) says:
“A short summary of the basic results of my study:
CO2 is insignificant as a greenhouse gas.
CO2 is not a poison or a pollutant.
CO2 is one of the two main building blocks of ALL plant life on Earth.
CO2 concentration has been up to ten times higher in the past
CO2 is good.”
Well, the last four points are irrelevant to whether the CO2 is a significant GHG. As to the first point, you are taking on all of mainstream science. Outside of a forum like this, good luck with that!
As regards trusting Google or wiki, Google is just a search engine, it’s the sources it leads you too that matter. Also with wikipedia, don’t trust it, follow the links from it and see where they lead, then decide.
@J Storrs Hall says:
June 9, 2011 at 4:28 am
You still have no explanation for the “acceleration” that the quadratic term is removing! And you have no idea what it is removing!
What is the forcing that causes the “knee” or bend around 1900?
J. Simpson: It’s a question of timescale: short term, forcing induces a changing temperature; but in the long term, the system will equilibrate and take up a new stable temperature that depends on the forcing. It’s much like the accelerator in your car: press it, and you get a change in speed; but the faster you go, the air resistance increases until it matches the engine power and you level off at a new, constant, speed. It’s the standard finite impulse response curve, if you’ve ever studied control theory.
You need to consider several things here. Yes there will be a controlling negative feedback (sorry IPCC) , increased plank emissions (T^4 , not linear) and some weather based feedback. However the initial response like you car is acceleration proportional to the forcing. You seem the dismiss, or rather ignore, the quadratic despite having fitted it. What do you think it represents?
The impulse response will start off as that quadratic and then fade over time, what do the consider the time constant of the global mass of water to be in this context? You are plotting yearly data and the hypothetical equilibrium could be centuries in coming.
You do have a point about feedback though and this will not be taken into account by integrating the dT/dt caused by the forcing. In fact I suspect the negative coeff that surprised you may well be that feedback. This answers a problem I was having with some similar work and the quadratic was too strong.
If that does provide a means to get a handle on a value for the feedback it will be worth writing a paper about.
Thanks for your comment.s
BTW what’s this “optimiser” you refer to?
John B says:
“Outside of a forum like this, good luck with that!”
Truth is not important, but luck is?
John, why don’t you measure the global warming at the place where you live so that you can see that it is not an increase in GHG’s that has caused it? Then we can add the results to my pool table!
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
If the rate of increase in minimum temps. is greater than the rise in maxima & mean temps. you are right that the warming is or might be caused by an increase in GHG’s. You can do a straight linear regression (time against temperature) from all the data that you can get for minima, maxima and means from the station where you live.
Very simple really. Statistics 104. Just some work to copy and paste in Excel and do the trendlines…..
We will talk again when you have some results.
Edim says:
June 8, 2011 at 11:21 pm
Yes, it was probably closer to 200ppm which is the average during glacial periods. It can certainly vary close to the surface. After all the sources of CO2 are very near the surface and CO2 is heavier than air. In calm air it can build up. There’s no evidence at all that it varies much over short periods of time away from active sources and sinks. That’s why our gold standards are places like Mauna Loa, the Antarctic, balloon soundings, and samples taken by aircraft.
Short peaks are recorded where there is sufficient snow accumulation. Entrainment happens in as little as 8 years (Law Dome). The entrained air samples match the CO2 concentration measured at above-ground sites. Places where the snowfall is heavy go back the least amount of time. Where there is little snow accumulation such as the Antarctic interior it takes hundreds of years for entrainment and the entrained air samples then reflect an average over a longer period of time. These cores go back much farther in time. The point is that ice core data has certain constraints but those constraints aren’t so onerous that it makes them “unreliable” nor incapable of recording short-lived spikes.
“CO2 has been much higher than now during three periods of the last 200 years, most recently in the 1940s”
Probably because the samples were taken downwind from a wartime industrial source that wasn’t there before WWII kicked into high gear. There is zero evidence that CO2 varies much or rapidly at any significant remove from active sources and sinks. It’s well mixed into the global troposphere by turbulence. That’s why Mauna Loa and the interior Antarctic closely agree with a lag of a couple years for the Antarctic because it takes longer to migrate there from the sources and the interior is somewhat shielded from mixing by the polar vortex. There is also some annual variation between northern and southern hemispheres as the change of seasons changes the activity level of sources and sinks.
Dave,
I am very sceptical about that. This article is a good summary of my view:
http://hubpages.com/hub/ICE-Core-CO2-Records-Ancient-Atmospheres-Or-Geophysical-Artifacts
Good thing is, when the cooling gets going in the next decades, we will have a TEST. I predict CO2 decrease.
Philip Shehan: The red line in figure 2 is the blue line in figure 1, with the new coefficient the optimizer gives it. Since it clearly cannot be representing a warming response in that configuration, you could very reasonably say that the optimizer did use it as a fudge factor.
J. Simpson:
http://wattsupwiththat.com/2011/06/06/earth-fire-air-and-water/#comment-676602
Dave Springer,
I generally agree with your comments. But in this case, the fact is that Beck et. al recorded CO2 measurements taken from such disparate sources as the unpopulated Ayrshire coast of Scotland, from mountain peaks, and from mid-ocean crossings on the windward side of ships transiting the Pacific and Atlantinc Oceans, the South Seas, the Sea of Okhotsk, the Arctic Ocean, etc. This was done to avoid false readings due to industrial activity.
Many Nobel Laureates participated in the CO2 data collection effort, with internationally esteemed scientists such as J.S. Haldane among them. They were meticulous and took copious notes, and made detailed drawings of their test apparatus. Probably most importantly, they were not government subsidized. They cared a great deal about their reputations, and they knew their work would be scrutinized by their fellow scientists.
Their CO2 readings were accurate to within ≈3%. Thus, there is little doubt that CO2 levels have varied much more than what is currently assumed.
Bob Longworth says:
June 8, 2011 at 6:09 am
The rate of increase in atmospheric CO2 exactly matches the growth rate in anthropogenic emissions. Half of what we emit remains in the atmosphere and this ratio has held true since the industrial revolution began through today. In fact it’s sometimes a point of concern for climate boffins because they don’t understand why as anthropogenic CO2 emission during the industrial era grew exponentially the ability of natural CO2 sinks to take it up also grew exponentially. They don’t know if the sinks will continue to grow in capacity commensurate with growing emission rates or whether the sinks may become saturated and start taking up less than half.
I hypothesize that there is a natural equilbrium point of 280ppm and the farther anthropogenic emissions push the atmosphere out of equilibrium the faster the natural sinks will take it up. I further hypothesize that anthropogenic emission ceased the natural sinks would remove it at the same pace it was added. The removal would be the fastest at the outset and diminish in magnitude as it became less and less out of equilibrium.
This is how simple equilibrium situations work. Take a hot piece of steel and put it in contact with a cold piece of steel of the same mass. The temperature difference will fall rapidly at first and become slower and slower as the equilibrium temperature is approached. It appears CO2 concentration in the atmosphere works the same way. The further out of equilibrium it is driven by anthropogenic sources the faster the sinks take it up.
Smokey says:
June 9, 2011 at 8:02 am
“But in this case, the fact is that Beck et. al recorded CO2 measurements taken from such disparate sources as the unpopulated Ayrshire coast of Scotland, from mountain peaks, and from mid-ocean crossings on the windward side of ships transiting the Pacific and Atlantinc Oceans, the South Seas, the Sea of Okhotsk, the Arctic Ocean, etc. This was done to avoid false readings due to industrial activity.”
The funny thing is that Beck’s historical survey of CO2 measurements show wild fluctuation from 1810 to 1950 then mysteriously become a perfectly smooth curve from 1950 to present. One might reasonably ask what happened in 1950 that changed everything. The answer is that was when electronic CO2 sensors replaced chemical methods of determining CO2 concentration. You can extol the credentials of those performing the chemical measurements all day long but at the end of the day you are still faced with the fact that when the chemical measurement era ended and the electronic measurement era began the wild fluctuations of the past disappeared. Explain that to me without resorting to extolling the virtues of 18th century scientists.
“You can extol the credentials of those performing the chemical measurements all day long but at the end of the day you are still faced with the fact that when the chemical measurement era ended and the electronic measurement era began the wild fluctuations of the past disappeared. Explain that to me without resorting to extolling the virtues of 18th century scientists.”
Those wild fluctuations disappeared because they are diluting the AGW message.
Dave Springer,
Good points. However, others have replicated the CO2 titration methods based on drawings taken directly from the notebooks of the scientists who took the original measurements. The results agree with modern CO2 measurements within ≈3%. For the 1940’s measurements, the fact that industry was ramping up world-wide, along with the fact that numeorus cities were fire-bombed into oblivion could explain the higher CO2 measurements. Since then the biosphere has reacted, and absorbes atbout half of the emissions. I’m not sure about the early 1800’s spike, but unless major errors can be identified in the test methods used, I accept their results. To do otherwise is non-science.
Edim says:
June 9, 2011 at 7:52 am
“I am very sceptical about that.”
So was I. Skepticism is part and parcel of science. I spent a long time trying to indict ice core data but couldn’t do it to my satisfaction. Agreement between recently entrained bubbles and the Mauna Loa record can’t be ignored. While one might entertain the notion that the record might not be accurate going back thousands of years it appears very clear that it is quite reliable going back 200 years given it was confirmed going back 60 years. Then going back hundreds of thousands of years we see repeatability in the record where during glacial epics the entrained air was roughly 200ppm and during interglacials roughly 280ppm. If there was progressive deterioration of entrained samples one would expect this to show up as increasingly different readings during glacial/interglacial periods as one measures older and older ice age cycles. The hypothetical complaints of Jaworski et al do not appear to be backed up by any empirical evidence while the accepted interpretations appear to be in accord with disparate geological evidence at every encounter. The acid test of any system of measurement is whether or not it is in satisfactory agreement with other methods.
It is for this very reason that I indict the common assumption by climate boffins that the earth’s albedo is more or less constant over time. Different methods at measuring albedo accurately are not in satisfactory agreement and fall in the range of 30%-40%. This is a huge uncertainty as it equates to a difference in surface forcing of 25 watts per square meter and where the forcing by anthropogenic GHGs are an order of magnitude lower. The one thing that the few attempts to measure earth’s albedo over a period of years DO agree on is that its albedo is not constant and fluctuates by as much as 1% from one year to the next with perhaps the best study IMO (Earthshine, which measures the intensity of light falling on the new moon) showing a 5 year trend of constantly increasing albedo which happened to coincide with a flat line global average temperature as measured by satellites over the same period.
This article is a good summary of my view:
http://hubpages.com/hub/ICE-Core-CO2-Records-Ancient-Atmospheres-Or-Geophysical-Artifacts
Good thing is, when the cooling gets going in the next decades, we will have a TEST. I predict CO2 decrease.
J Storrs, thanks , and thanks for letting me know the long period phase approximated a line during the 20th century, but in any case I was referring to your previous analysis, which didn’t show the 259 year cosine.
@Dave Springer
Thanks for your posts. I’ve learned a great deal from them more than most of the stuff I’ve read over the years.
To Dave Springer,
You have a lot of wild spikes in the raw flask data and continuous measurement data. These could be anthropogenic. Those spikes, however, are flagged and not included in the reported averages. As a result, the averages being reported from stations around the globe are likely natural background and reflect changes in the major natural sources (equatorial pacific) and sinks (Arctic ocean).
Smokey says:
June 9, 2011 at 8:48 am
I asked you to explain to me why there are no wild fluctuations in CO2 measurements since the invention of the electronic IR CO2 sensors circa 1950. All you did was ( as I asked you not to do) once again rise in defense of chemical measurements performed by scientists of the more distant past. I don’t care about the theoretical precision of the chemical methods. I want to know why there is a great disparity between the chemical analysis record and the electronic methods. It appears one or the other was, regardless of theoretical accuracy, either not accurate in practice or atmospheric CO2 in 1950 stopped making large annual divergences from the norm.
Try again and this time explain what I asked you to explain.
HenryP said “John, why don’t you measure the global warming at the place where you live so that you can see that it is not an increase in GHG’s that has caused it? Then we can add the results to my pool table!”
And I say, if your pool table means anything, publish! Seriously, a Nobel prize awaits.
Fred H. Haynie says:
June 9, 2011 at 11:45 am
“To Dave Springer,
You have a lot of wild spikes in the raw flask data and continuous measurement data. These could be anthropogenic. Those spikes, however, are flagged and not included in the reported averages. As a result, the averages being reported from stations around the globe are likely natural background and reflect changes in the major natural sources (equatorial pacific) and sinks (Arctic ocean).”
http://cdiac.ornl.gov/ftp/trends/co2/Jubany_2009_Daily.txt
Above is daily raw data from 1994 to present of CO2 concentration measured at Jubany station in Antarctica. There are a few gaps in the data presumably due to sensor or recorder outages and a couple of wild spikes lasting a few days at most again presumably due to sensor malfunction. Otherwise the record is one of gradually increasing CO2 level with an annual upward trend that matches Mauna Loa.
Henry@John B
there are none so blind as those who do not want to see (for themselves)
but I can guess that you are also one of those whose livelyhoods depends on this whole scam of more GHG’s causing warming being true. Must be horrible to discover one day that your whole life (and livelyhood) is based on a lie.
I was just as surpised about my own findings. I was initially convinced Al Gore was not a lier…
PS
My pool table
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
is a work in progress
there is more coming, even if you do not want to put some work into it.
Dave Springer,
You ask why there are no wild fluctuations in the recent CO2 record. I don’t know, I’m not too good at proving negatives. But I accept the CO2 measurements recorded by Beck et. al, which were done by dozens of reputable scientists and which are in agreement. Those 90,000 readings are the only record we have of past CO2 levels in the century preceeding intrument recordings.
The test apparatus used has been replicated and validated. I agree that the current readings have no unusual fluctuations. But that does not falsify the 90,000 readings taken. At this point the differences are unexplained. But unless you can falsify the methodology recorded by Beck, it makes no sense to assume that the results were not broadly accurate.