Guest Weblog: CO2 variation by Jim Goodridge, former California State Climatologist

Moderators note: This is reposted from an essay that Jim sent to me. Jim was the State Climatologist for California for many years, and still does consilting work for the Californiua Dept. of Water Resources on rainfall studies. Jim has a command of simplicity in presentation, as you’ll read below. Jim’s presentation lends some insight into why CO2 increases lag temperature in historical and proxy climate records. Jim has also done another essay I’ve posted which relates The Pacific Decadal Oscillation, Sunspots, and Length of Day variances to rainfall patterns in California which you can read here.

Atmospheric Carbon Dioxide Variation

Jim Goodridge

California State Climatologist (retired)

jdgoodridge [at] sbcglobal dot net


Carbon dioxide in the atmosphere is commonly modeled with the measurements from NOAA”S Mauna Loa observatory; the annual rate of increase in this data set is 1.4 parts per million.


This increase fluctuates 6.3 ppm on an annual cycle with the highest in May and the lowest values in October.


The solubility of carbon dioxide in water is listed in the Handbook of Chemistry and Physics as a

declining function of temperature.


The rising values of atmospheric carbon dioxide during the time of the Mouna Loa measurements could clearly be a function of reduced solubility of CO2 in the oceans of the Planet.

The source of heat needed to drive the increasing carbon dioxide from the oceans of Earth into the atmosphere is the Sun. The solar irradiance has been measured from orbiting satellites since 1978. Irradiance was highly correlated with the historic sunspot numbers.


Schove’s index of sunspot numbers dated from the year 1500. Combining Schoves index with the Royal Belgium Observatory’s measurements an index 1749 a 500-year index of irradiance was developed.


If we are to believe that the irradiance and sunspot numbers correlate for the 3 sunspot cycles from 1975 to 2005 them it can be assumed that a correlation for the 1500 to 2005 follows. It is common to think of individual sunspot cycles to be independent events. This was not the case during the Maunder Minimum of sunspot activity from 1650 to 1710 when Earth was in the middle of the Little Ice Age.

The sunspot record needs to be examined in its entirety rather than as individual sunspot cycles. The method to do this is by calculating the accumulated departure from the average of all the sunspot numbers of the entire 500-year index. This reveals the cooling during the Maunder Minimum and the current “global warming”. The current warming of 15 watts per square meter began in 1935, based on the sunspot record.

The reason oxygen is 600 times as abundant as carbon dioxide is due to the robustness of microorganisms. The oxygen-carbon dioxide balance on the Planet has for billions of years been a function of the photosynthesis process.

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November 4, 2007 12:28 pm

Weakest hurricane season since 1977, and (from the California Climate link) a severe drought for Ca in 1977.
I’m needing some reasurance here.
A drought this year will be a disaster, not just for water rationing [ we have been through it before and coped] , but because of the political hay the warmongers will make out of it.
Todays Bee has a big op/ed, complete with polar bear pictured on crumbling ice-[what climate change op ed would be complete without one of those?], by some self serving author named John Cox.
He is peddling drought for California this year as being a prediction of computer climate models and validation of global warming.

November 4, 2007 1:43 pm

Welcome to Watts Up With That! I have been trying to understand the solar influence on our climate for a long time and post my musings at the Dalton Minimum Returns. Your Accumulated Departure From Average Solar Iradiance chart stops about 2000. Have you looked at the change since then, the last seven years with a very quiet sun this summer and fall? The charts at pmod/wrc show a decline. I will continue to study your paper and will post my thought on Dalton Minimum Returns. Again, thanks for sharing your paper.

James Bailey
November 5, 2007 5:19 am

I have been troubled by the contradiction inherent in climate scientists arguing that the whole worlds CO2 readings can be represented by one or two remote locations, while at the same time averaging values from all around the world to get the globes temperature. Does measuring near a smokestack or a city give results that are biased? Can the average effect be cleanly seperated from the local effects, especially since they are non-linear to begin with.
If the ability for CO2 to make a difference in temperature depends upon its concentration levels, and if those levels vary around the world, then shouldn’t the effect vary locally? Worse, there is supposed to be an overlap between the IR spectrum of CO2 and H2O which is significant compared to the total CO2 IR spectrum. H2O levels vary significantly. Since the basic effect is logarithmic, locally high levels of H2O should greatly reduce the additional effect of CO2 in the overlap region, with locally low levels of CO2 greatly enhancing the additional effect of CO2. (Estimating the total feedback from additional H2O evaporation will complicate this even further.)
Anyways, could you explain to me the reasoning used for using the average CO2 levels, and for representing that average with a remote measurement? Do you have faith in this reasoning, i.e. should the effect from using the average to get a result be close to the result from averaging local effects? What assumptions are needed for that to hold true?
Anyways, I am just trying to wrap my head around the complexity of the problem, and the reliability of the reasoning. I haven’t even gotten to thinking about the H2O cycles, and how additional warming from CO2 should perturb this cycle, or if the CO2 reacts in air or sunlight, or some other oddball effect.
Thanks very much, even if it is just to point me on my way.
Jim Bailey

November 5, 2007 9:52 am

this is some great info. It confused me at first but I picked up on it very quickly. I think it only confused me because it is early in the morning haha.

brad tittl
November 5, 2007 11:07 am

It saddens me to see charts that are Zoomed. It is always good for eye candy, but is usually a sign that someone is obfuscating something.
I agree with everything in the essay, but I get nervous when people who are smarter than I engage in deception even by accident.
The above charts can be blamed on Excel. By default it makes charts that look like this.

November 5, 2007 12:54 pm

Actually I find the seasonal cycling of the CO2 of great interest. You may want to look at this chart to see it more clearly: Note the annual June peak and the Sept/Oct bottom out of the cycling. You should then compare this with the ice cover in the Northern Hemisphere: Very interesting similarity with a 45 day to 60 day lag. Here is the main website for Cyrosphere Today:
My take on this is as ice cover decreases over the arctric during the summer time, more water surface area is exposed to dissolve the CO2. Note that the Southern Hemisphere runs in reverse with ice cover naturally, however the seasonal “variation” melting is vastly larger. As a consequence, Global Sea Ice coverage (North and South combined) peaks during the Northern Winter and troughs around spring time. So one might say, that due to the Southern Ice coverage and North spring growth of plants, CO2 is pulled out of the atmosphere at a phenominal rate. Given this amount of CO2 uptake, the claim mankind has anything to do with this is just absurd. The amount of CO2 in the air is largely dependent on the surface water temperature and ice coverage and both of these are directly influenced by the sun.

November 5, 2007 2:44 pm

Why does the C02 amount fluctuate on a yearly basis?

November 5, 2007 5:31 pm

CO2 varies seasonaly depending on water temp and biotic influences.
The reason CO2 is monitored in so few places is because Keeling had to search for years to find proper places to find global CO2 (per Scipts institute).
Anyplace else you measure it you get random noise at about 400 +/- 100 ppm that can vary 50ppm in seconds depending on wind direction.
Another thing that creeps me out is this quote from Scipts webpage “dissatified with current instruments Keeling revived the 1916 model and modified it to suit his needs”

November 5, 2007 7:05 pm

I’ve seen figures that list CO2 at 353 ppm and 360 ppm. Now I’m reading on Wiki (that paragon of scientific truth) that it’s actually 380.
Watt’s Up With That?
And what IS the actual number? (And what’s the +/-?)

November 6, 2007 4:38 am

[…] – Global Warming I wonder what Al Gore has to say about this article which clearly shows the cyclical nature of “Global Warming”. As usually the liberal media has surpressed another scientific piece of evidence against Gores […]

November 6, 2007 7:09 am

I am curious about the red “annual” curve in the middle plot. Since it seems to have more than one point per “year”, is it really a 12 month average of some sort?

James Bailey
November 6, 2007 7:24 am

Thanks davidcobb.
So, in a period where industry was poorly distributed, Keeling could not find places on any continent, except Antarctica, where the random noise wasn’t a dominant feature. To get noise free measurements, he had to be thousands of miles from these randomized land sources. Yet we believe in near instant diffusion throughout the atmosphere, at least on the time scale of the models.
Did they say why these remote noise free regions could reliably characterize all the rest of the world?
Did they say why they could reliably ignore local effects? Maybe it is a should instead of a could. Do high altitude balloon measurements vary as much?
Here is a good one. If you live near a major CO2 source, is there clear evidence of warming based upon the CO2 being blown towards you rather than away from you? What if the major source is shut down for long maintenance periods?
Re: Evan Jones,
I don’t know the latest values either, but I have two possible reasons. The first is the authors may not all be up to date. Using the graph above, ~353ppm could be from a source in the early 90’s, 380 ppm is much more recent. The second possibility could be the units. Some measurements are in parts volume and some in parts mass. CO2 is heavier than N2 and O2, which dominate the atmosphere, so it should read higher in parts mass than in parts volume.
The possiblility that it could be different in different places seems to be settled by a perverse argument that the poor localized mixing of CO2 causes such random variations that it is impossible to measure, yet we can safely assume uniform mixing throughout the world so that we can use the reliable measurements we can make in locations that are both extreme and remote to represent the real values all over the world.
If I argued the same with temperature, it would be laughed out of the park. Especially after it was clear that I chose Hawaii and Antarctica as my representative samples.
Maybe they are right. But it looks to me as if they choose to accept this rather than test it. On the other hand, they clearly don’t accept any of the old proofs of a Medievel Warm Period that was as warm or warmer than today.
This seems to me to be rife for scientific exploration. Properly done, we could gain great knowledge of sources, sinks, dispersion, diffusion and mixing.
We believe that almost half of what we add to the skies gets taken out by some sink, with the rest getting nearly instantaneously well mixed througout the atmosphere. If that is true, the levels have to be higher downwind of sources, being reduced downwind of sinks. Since we are adding to levels, the ocean should be a relative sink. But is it? If the readings are higher the closer you get to Asia, and lower the closer you get to the Americas, then we would know just how well the ocean is acting as a sink.
A researcher could even phrase all his research proposals as truly being necessary to fully understand anthropogenic global warming.

November 6, 2007 8:32 am

I was thinking more on this last night when another question came to me regarding CO2 measurements. Since Mauna Loa is in the Northern Hemisphere and the seasonal CO2 cycling is in phase with the Northern Seasons, I wonder if a Southern Hemisphere CO2 reading is being taken and if it also shows a seasonal cycling? Is the Southern CO2 cycling in phase with the Southern Seasons?????? If it is, then is the slope of increase and decrease sharper than in the Northern Hemisphere to match the sharper slope of Antarctic ice cover variation?
There is an important implication in this colloration, there is an optimum ice coverage that either increases or decreases CO2 uptake from the atmosphere to the water as reflected in the seasonal CO2 cycling. If the Northern and Southern CO2 reading cycling in reverse of each other, i.e. in phase with their respective seasons, then we should see a statistically significant difference between the Northern and Southern Hemipheric CO2 readings. Which leads me to a suspicion: If the Southern Hemisphere has shown no Global Warming according to the temperature data, and that the averaging in of the Northern Hemisphere with the Southern Hemisphere gave us the appearance of “Global Warming” when in fact it was Northern Hemispheric warming, have we been similarly mislead with planetary CO2???? What is the Southern Hemisphere’s CO2 history????????????????????

November 6, 2007 3:05 pm

Southern Hemispheric CO2 readings: Something is very odd, there is virtually no seasonal cycling in these monthly readings. The graphic shows a slight cycling but the digital data shows very slight less than 1 ppm variation for the season.
“Monthly values are expressed in parts per million (ppm) and reported in the 2003A SIO manometric mole fraction scale. The monthly values have been adjusted to the 15th of each month. Missing values are denoted by -99.99. The “annual” average is the arithmetic mean of the twelve monthly values.
In years with one or two missing monthly values, annual values were calculated by substituting a fit value (4-harmonics with gain factor and spline) for that month and then averaging the twelve monthly values.”
“Atmospheric CO2 concentrations (ppmv) derived from flask and in situ air samples collected at the South Pole”
Notice that the chart starts in 1957 and has a virtual straight line slope to 2004, so atmospheric CO2 was rising before they even heard of Global Warming. Very odd indeed. Notice all the other graphics have a similar straight line trend with minor squiggles to 2004.

November 6, 2007 4:33 pm

Scripts laudes Keeling as one of the first believers in global warming who set out in the early fifties to find evidence of the rise CO2. The Keeling curve isn’t named that because he was the first to identify it, but because he and the team he left behind at scripts are the only ones who know how to monitor global CO2. If anyone knows of any study ( independant of Scripts )demonstrating the Keeling curve I would like to see it.

November 9, 2007 9:27 am

“The rising values of atmospheric carbon dioxide during the time of the Mouna Loa measurements could clearly be a function of reduced solubility of CO2 in the oceans of the Planet.”
Not true. It’s clear that increasing CO2 levels come from the burning of fossil fuels. One reason we know that the ocean is not the source is because the CO2 concentration in the ocean has been increasing. Further, C12/C13 isotope ratios confirm FF as a source for atmospheric CO2 increases.

November 10, 2007 2:29 pm

Boris, all the C12/C13 ratios prove is that recent CO2 hasn’t been absorbed or sequestered, what it doesn’t prove is why. Regardless of where the CO2 comes from, the issue is the sources of CO2 and rates of sequestration and plant growth. Even you as an AGW supporter must acknowledge that mankind only creates a very small fraction compared to what nature does on an annual basis. Simply trying to blame one source among many sources is disengenuous.
The essence of AGW claims is that more CO2 is being produced than absorbed by nature. The problem with that claim is nature’s ability to absorb CO2 is highly variable just as weather it is certainly not constant. What Goodridge is saying is that we haven’t considered adequately all the ways in which nature absorbs CO2, one of them being marine photosysthesis.

November 10, 2007 2:35 pm

If the Northern Hemispheric oceans do play a role in the seasonal cycling of CO2, the most likely factor would be winds off the Sahara blowing iron dust to fertilize the Atlantic promoting marine growth which in turn metabolizes the CO2. Since these Saharan winds do not cross the equator, the Southern Oceans do not get the benefit of iron fertilization and maybe also explains why there is very little cycling of CO2 in the Southern Hemisphere given the smaller proportional land mass below the equator. Which also leads us to a possible 2nd reason why CO2 is rising, beyond the melting permafrost off gassing CO2, that being a lack of iron fertilization of the Northern Hemispheric Oceans due to non-drought conditions. Without drought, i.e. the lack of rainfall to contain the dust, a wetter climate automatically induces higher atmospheric CO2 by virtue of limited nutrients for marine photosynthesis. According to the historic record, ice ages tend to be periods of drought, which in turn causes more dust in the air, promoting marine photosynthesis and thus pulling CO2 out of the air. So from this perspective given the huge scales, it would seem to be obvious CO2 responds to the change in climate, it does not cause the change in climate.
Note slide 16 & 45 and its limiting factors, where the bulk of marine photosynthesis occurs. Note the high levels of marine growth off of the Sahara and in the subarctic.

November 10, 2007 2:39 pm

JB: Thanks.

November 27, 2007 12:05 pm

I disagree! This guy sucks!

January 25, 2008 3:09 pm

[…] out that former California State Climatologist Jim Goodridge posted a short essay on this blog, Atmospheric Carbon Dioxide Variation, that postulated something […]

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August 21, 2008 6:04 pm

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