Guest post by Lon Hocker
Abstract
Differentiating the CO2 measurements over the last thirty years produces a pattern that matches the temperature anomaly measured by satellites in extreme detail. That this correlation includes El Niño years, and shows that the temperature rise is causing the rise in CO2, rather than the other way around. The simple equation that connects the satellite and Mauna Loa data is shown to have a straight forward physical explanation.
Introduction
The last few decades has shown a heated debate on the topic of whether the increase of CO2 in the atmosphere is causing rising temperatures. Many complex models have been made that seem to confirm the idea that anthropological CO2 is responsible for the temperature increase that has been observed. The debate has long since jumped the boundary between science and politics and has produced a large amount of questionable research.
“Consensus View”
Many people claim that anthropological CO2 is the cause of global warming. Satellite temperature data, http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt, and Mauna Loa CO2 measurements, ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt, are well accepted and freely available to all researchers. Figure 1 shows a plot of the Ocean Temperature Anomaly from the satellite data shows a general rising trend. Shown along with the temperature data is a simple linear model showing the temperature rise as a linear function of CO2 concentration. This shown linear model is:
Temperature Anomaly = (CO2 -350)/180
No attempt has been made to optimize this model. Although it follows the general trend of the temperature data, it follows none of the details of the temperature anomaly curve. No amount of averaging or modification of the coefficients of the model would help it follow the details of the temperature anomaly.
Figure 1: Ocean Temperature Anomaly and linear CO2 model
Derivative approach
An alternate approach that does show these details is that the temperature anomaly is correlated with the rate of increase of CO2. I discovered this independently and roughly simultaneously with Michael Beenstock and Yaniv Reingewertz http://economics.huji.ac.il/facultye/beenstock/Nature_Paper091209.pdf.
Applying this model to the Mauna Loa data not only shows the overall trend, but also matches the many El Niño events that have occurred while satellite data has been available. The Figure 2, shows the derivative model along with the observed Ocean Temperature Anomaly. The model is simply
Temperature Anomaly = (CO2(n+6) – CO2(n-6))/(12*0.22) – 0.58
where ‘n’ is the month. Using the n+6 and n=6 values (CO2 levels six months before and six months after) cancels out the annual variations of CO2 levels that is seen in the Mauna Loa data, and provides some limited averaging of the data.
The two coefficients, (0.22 and 0.58) were chosen to optimize the fit. However, the constant 0.58 (degrees Celsius) corresponds to the offset needed to bring the temperature anomaly to the value generally accepted to be the temperature in the mid 1800’s when the temperature was considered to be relatively constant. The second coefficient also has a physical basis, and will be discussed later.
Figure 2: Ocean Temperature Anomaly and derivative CO2 model
There is a strong correlation between the measured anomaly and the Derivative model. It shows the strong El Niño of 1997-1998 very clearly, and also shows the other El Niño events during the plotted time period about as well as the satellite data does.
Discussion
El Niño events have been recognized from at least 1902, so it would seem inappropriate to claim that they are caused by the increase of CO2. Given the very strong correlation between the temperature anomaly and the rate of increase of CO2, and the inability to justify an increase of CO2 causing El Niño, it seems unavoidable that the causality is opposite from that which has been offered by the IPCC. The temperature increase is causing the change in the increase of CO2.
It is important to emphasize that this simple model only uses the raw Mauna Loa CO2 data for its input. The output of this model compares directly with the satellite data. Both of these data sets are readily available on the internet, and the calculations are trivially done on a spreadsheet.
Considering this reversed causality, it is appropriate to use the derivative model to predict the CO2 level given the temperature anomaly. The plot below shows the CO2 level calculated by using the same model. The CO2 level by summing the monthly CO2 level changes caused by the temperature anomaly.
Month(n) CO2 = Month(n-1) CO2 + 0.22*(Month(n) Anomaly + 0.58)
Figure 3: Modeled CO2 vs Observed CO2 over Time
Not surprisingly the model tracks the CO2 level well, though it does not show the annual variation. That it does not track the annual variations isn’t particularly surprising, since the ocean temperature anomaly is averaged over all the oceans, and the Mauna Loa observations are made at a single location. Careful inspection of the plot shows that it tracks the small inflections of the CO2 measurements.
The Mauna Loa data actually goes back to 1958, so one can use the model to calculate the temperature anomaly back before satellite data was available. The plot below shows the calculated temperature anomaly back to 1960, and may represent the most accurate available temperature measurement data set in the period between 1960 and 1978.
Figure 4: Calculated Temperature Anomaly from MLO CO2 data
Precise temperature measurements are not available in the time period before Satellite data. However, El Niño data is available at http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml making it possible to show the correlation between the calculated temperatures and the and El Niño strength. Note that the correlation between temperature anomaly and El Niño strength is strong throughout the time span covered.
Figure 5: Calculated Temp CO2 from CO2 and ENSO data
An Explanation for this Model
The second free parameter used to match the CO2 concentration and temperature anomaly, 0.22 ppm per month per degree C of temperature anomaly, has a clear physical basis. A warmer ocean can hold less CO2, so increasing temperatures will release CO2 from the ocean to the atmosphere.
The Atmosphere contains 720 billion tons of CO2 (http://eesc.columbia.edu/courses/ees/slides/climate/carbon_res_flux.gif), the ocean 36,000 billion tons of CO2. Raising the temperature of the ocean one degree reduces the solubility of CO2 in the ocean by about 4% (http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html)
Figure 6: Solubility of CO2 in water (While CO2 solubility in seawater is slightly different than in pure H2O shown above in Figure 6, it gives us a reasonably close fit.)
This releases about 1440 billion tons of CO2 to the atmosphere. This release would roughly triple the CO2 concentration in the atmosphere.
We have seen what appears to be about a 0.8 degree temperature rise of the atmosphere in the last century and a half, but nowhere near the factor of three temperature rise. There is a delay due to the rate of heat transfer to the ocean and the mixing of the ocean. This has been studied in detail by NOAA, http://www.oco.noaa.gov/index.jsp?show_page=page_roc.jsp&nav=universal, and they estimate that it would take 230 years for an atmospheric temperature change to cause a 63% temperature change if the ocean were rapidly mixed.
Using this we can make a back of the envelope calculation of the second parameter in the equation. This value will be approximately the amount of CO2 released per unit temperature rise (760 ppm/C)) divided by the mixing time (230 years). Using these values gives a value of 0.275 ppm /C/month instead of the observed 0.22 ppm/C/month, but not out of line considering that we are modeling a very complex transfer with a single time constant, and ignoring the mixing time of the ocean.
Conclusion
Using two well accepted data sets, a simple model can be used to show that the rise in CO2 is a result of the temperature anomaly, not the other way around. This is the exact opposite of the IPCC model that claims that rising CO2 causes the temperature anomaly.
We offer no explanation for why global temperatures are changing now or have changed in the past, but it seems abundantly clear that the recent temperature rise is not caused by the rise in CO2 levels.
================================================
Lon Hocker describes himself as: “Undergrad physics at Princeton. Graduate School MIT. PhD under Ali Javan the inventor of the gas laser. Retired president of Onset Computer Corp., which I started over 30 years ago. Live in Hawaii and am in a band that includes two of the folks who work at MLO (Mauna Loa Observatory)!”
Data and calcs available on request
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Alex says:
June 11, 2010 at 6:49 am
The signal you detect in the CO2 concentration tells us NOTHING about the source.
Rather, it tells us how efficient is the SINK.
The source is anthropogenic.
The sink are the oceans. The higher the surface temperature, the worse the sink efficiency. That is why you see the Al Nino signal.
Further, it is impossible to increase the ocean water temperature through all the depths. The temperature must follow the thermocline. Only the top layers of the ocean (about 400 m) can change the temperature.
We distinguish extrinsic and intrinsic sinks with respect to the atmosphere. The interface sea surface and atmosphere is not perfectly homogeneous so the remote (or diffuse) deep ocean must to be included in models. If not, the results would be biased.
On the other hand, the efficiency of photosynthetic protists and algae for absorbing carbon dioxide from the environment is as important as the geochemical processes:
http://www.sciencedaily.com/releases/2005/10/051011065902.htm
Carbon dioxide is good for life. I have no concern about its levels rising thru the last century:
http://www.sciencedaily.com/videos/2007/0603-can_carbon_dioxide_be_a_good_thing.htm
tallbloke says:
June 11, 2010 at 8:52 am
Joel and John,
Yes, I made a mistake with my question to Willis. Too early in the morning. :o/
My points about lag stand however.
I’m not sure if this is intended for me. But if it is: What point about what lag?
tallbloke says:
June 9, 2010 at 4:09 pm
John Finn says:
June 9, 2010 at 3:21 pm
I’ve just had my 3rd brandy
Good move. I reckon you’ll need a bit of cushioning when you realise the implications fully. Good to see you can envisage co2 levels falling though. 😉
___________________________________________________________________
Yes but the DATA will never show CO2 falling. Here is why.
“At Mauna Loa we use the following data selection criteria:
3. There is often a diurnal wind flow pattern on Mauna Loa ….. The upslope air may have CO2 that has been lowered by plants removing CO2 through photosynthesis at lower elevations on the island,…. Hours that are likely affected by local photosynthesis are indicated by a “U” flag in the hourly data file, and by the blue color in Figure 2. The selection to minimize this potential non-background bias takes place as part of step 4. At night the flow is often downslope, bringing background air. However, that air is sometimes contaminated by CO2 emissions from the crater of Mauna Loa. As the air meanders down the slope that situation is characterized by high variability of the CO2 mole fraction…..
4. In keeping with the requirement that CO2 in background air should be steady, we apply a general “outlier rejection” step, in which we fit a curve to the preliminary daily means for each day calculated from the hours surviving step 1 and 2, and not including times with upslope winds. All hourly averages that are further than two standard deviations, calculated for every day, away from the fitted curve (“outliers”) are rejected. This step is iterated until no more rejections occur…..”
To translate into English. We take lots and lots of readings. We assume CO2 in background air should be steady, So if we think the readings are to low we reject the data as “likely affected by local photosynthesis” if the readings are too high we reject the data as “sometimes contaminated by CO2 emissions from the crater of Mauna Loa.” We do this because we KNOW the CO2 is well mixed in the atmosphere.
An explanation of CO2′s thorough mixing in the atmosphere is given on page 8 of the EPA’s Response to Public Comments, Volume 2, in the section “Response 2-8:”
“…turbulent mixing (e.g., through wind and convection) dominates the distribution of gases throughout the atmosphere (below 100 kilometers in altitude). The mixing of substances in a gas or fluid is only dependent on mass when the gas or fluid is perfectly still, or when the pressure of the gas is low enough that there is not much interaction between the molecules. Therefore, all long-lived gases become well-mixed at large distances from their sources or sinks…”
The only way you will see CO2 readings drop is if “global warming” is thoroughly purged from our schools, campuses and politics. As long as grant money is based on “proving” Global Warming” the data will continue to show a rise in CO2.
Quinn the Eskimo says:
Why was there no runaway warming in the Vostok record?
Who is predicting “runaway warming”? What is being predicted is that there will be positive feedbacks that will tend to magnify the warming in the absence of these feedbacks…and such a prediction is in fact aligned with our current understanding of the forcings and temperature changes in the paleoclimate record, which seem to imply a reasonably large climate sensitivity. See, for example, here: http://www.sciencemag.org/cgi/content/summary/sci;306/5697/821
Nasif Nahle says:
June 11, 2010 at 12:06 am
You’ve not read it.
I read your posts, that’s how I know you are wrong.
1: you were wrong with the 88 g. Admit or deny?
2: you are wrong that a human exhales the full lung capacity [4
liters] in each normal breath. Admit or deny.
Quote again: “At rest, we breath 15-18 times a minute exchanging about 500 ml of air.” from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Pulmonary.html
From Wikipedia: http://en.wikipedia.org/wiki/Lung_volumes
“Tidal volume (Vt) = 500 / 390 mL measured The amount of air
breathed in or out during normal respiration. The volume of air an
individual is normally breathing in and out.”
Admit or Deny?
It is no shame to be wrong. Only in being wrong and denying it.
ck says:
June 11, 2010 at 3:19 am
See my more involved model in discussions above. The effect of anthropogenic forcing is necessarily negligible by the IPCC’s own accounting.
There is a contrarian opinion here: http://www.skepticalscience.com/Co2-trend-not-caused-by-warming-oceans.html
Most of the non-scientific comments tend to argue AGW vs non-AGW. That is no longer a useful concept because the world is not going to stop pumping CO2 into the atmosphere. Let us discard AGW entirely because no matter the conclusion, we are over that cliff.
Can we agree that our warmth comes from the sun and, regardless of the forcing agent, and even if it is a completely natural phenomenon, temperature and CO2 are both increasing? This argument should allow agreement from all sides and merely states that (1) we are observing a physical phenomenon and (2) that observation does not necessarily imply causation.
If we agree to that, it seems straightforward to be able to graph a correlation of some kind without that correlation necessarily implying causation. I simply want to know if there is a general consensus that we can measure a warming trend at this moment in history. I stipulate that the historical record shows temperatures much warmer than these and that those cannot have been Anthropogenic because humans didn’t exist.
But that is not the point. The point is that the world looks much differently than it did even as recently as 1800. At the same time, the weather is now changing faster than we can. The cause doesn’t matter if we enter a major extinction event.
Six liters of air gives 0.006 cubic meters, not 0.0006 cubic meters. Admit it or not?
Nasif Nahle says:
June 11, 2010 at 8:52 am
Six liters of air in my lungs are 0.006 cubic meters, not 0.0006 cubic meters
Any competent biologist would know that normal breathing only exhales a tenth of the total lung capacity. This is called the ‘Tidal Volume’ and is illustrated here:
http://en.wikipedia.org/wiki/File:LungVolume.jpg
Bottom line, humans exhale 1/20 of a gram per normal breadth. Not 88 gram, not 0.53 gram…
Leif and Nasif:
Very interesting exchange, and provides an example of why it is so difficult for folks to change their perspectives. You are seeing the global warming debate in miniature.
Nasif: It is always good to have an open mind, and be able to accept that you might have made a mistake. Changing your mind is liberating.
Leif: Banging someone over their head when they are wrong only hardens their position. Best to be friendly and to point that 88 x 11 x60 x8 means he would exhale 400Kg of carbon overnight, so it is likely he missed a decimal point somewhere.
Living in Hawaii is good for your soul.
Aloha to you both and all other participants,
Lon
Gail Combs says:
All hourly averages that are further than two standard deviations, calculated for every day, away from the fitted curve (“outliers”) are rejected. This step is iterated until no more rejections occur…..”
Wow. Not hard to get a 95% confidence level from that data set I am sure.
>>1: you were wrong with the 88 g. Admit or deny?
>>2: you are wrong that a human exhales the full lung capacity [4
liters] in each normal breath. Admit or deny.
He knows he should admit. I expect he will ignore.
But thank you for setting it straight, Leif.
Imagine the food intake required for exhaling 1 kg of CO2 each minute 😉
I just realized that Lon and his wife are large donors to the Big Island (Hawaii) Republican party, so I can and do assume he has a political interest in discrediting AGW.
The Big Island isn’t that big.
Bart: Thank you for doing all the heavy lifting here. Is it too late to make you a co-author? Better yet, you rewrite this and extend it, adding your more rigorous math, and greater knowledge of the facts.
I owe you a lot, friend.
Dr. Tom says:
June 11, 2010 at 2:07 pm
I just realized that Lon and his wife are large donors to the Big Island (Hawaii) Republican party, so I can and do assume he has a political interest in discrediting AGW.
The Big Island isn’t that big.
Your causality is backwards in this comment too…
Bart says:
No…It’s necessarily negligible by your misunderstanding. Don’t blame your mistakes on the IPCC.
Niels A Nielsen says:
June 11, 2010 at 1:50 pm
>>1: you were wrong with the 88 g. Admit or deny?
>>2: you are wrong that a human exhales the full lung capacity [4
liters] in each normal breath. Admit or deny.
He knows he should admit. I expect he will ignore.
But thank you for setting it straight, Leif.
Imagine the food intake required for exhaling 1 kg of CO2 each minute 😉
You either didn’t read my post; what a pity. 🙂
The final paragraph in my post says:
The trick consists in omitting the volume of mixed air that I exhale in each breathing movement and applying pure mathematics.
Now read the following post, which says:
Nasif Nahle says:
June 10, 2010 at 1:41 pm
Now, I exhale approximately 0.006 m3 of mixed air during one breathing movement. This gives a real molecular mass of carbon dioxide of 0.012 moles during each exhalation. It means about 0.53 g in each exhalation, which gives ~3.1 metric tons per year. We have to put special attention to these small things when we are investigating volumes of CO2 forming part of any medium.
Following with the same example on my respiration, if I don’t take into account the volume of air in my lungs, I would conclude that the partial pressure of the carbon dioxide in my lungs would be 0.05 atm m, which is a subatmospheric pressure that makes possible the respiration. However, given the small sample of mixed air in my lungs, the real partial pressure of carbon dioxide in my lungs is 0.0003 atm m. It happens because my lungs expand when I lower my diaphragm, so the concentration of CO2 into my lungs diminishes.
Read the posts, that’s all. On the other hand, Dr. Leif assured that 6 liters of air were equivalent to 0.0006 cubic meters, which is incorrect.
Lon Hocker says:
June 11, 2010 at 1:36 pm
Best to be friendly and to point that 88 x 11 x60 x8 means he would exhale 400Kg of carbon overnight, so it is likely he missed a decimal point somewhere.
Leif Svalgaard says:
June 10, 2010 at 12:08 pm
Nasif Nahle says:
June 10, 2010 at 9:21 am
“Take this assertion from a biologist who exhales ca. 88 g of carbon dioxide 11 times each minute.”
more like 0.04 gram 11 times each minute, or ~2000 times as little…
So that biologist must do a lot of heavy breathing…
——
My little [friendly enough] hint should have been enough to make him realize that there was some mistake. I think it is important that such trivial mistakes get corrected right away [easy to do] as some readers otherwise would remember this little tidbit from a biologist.
Same thing with the ‘Tidal Volume’. Humans only exhale about half a liter with each breadth. Small things, but no reason to have them wrong.
Joel Shore
“Who is predicting “runaway warming”?”
Joe D., that’s who. He stated that we should hope it wasn’t true that warmer oceans drove increased CO2. To quote him directly: “Warmer ocean -> more CO2 -> warmer atmosphere -> warmer ocean -> more CO2 -> runaway greenhouse effect.”
We all know that the Vostok record shows that CO2 increases lag temperature increases by around 800-1000 years.
Yet the Vostok record shows no runaway warming, and that increased CO2 did not cause the warming that preceded it. Why this is so is a very important point. Climate repeatedly transitioned from warming to cooling coincident with high and increasing CO2. This invalidates the runaway warming scenario, which is why I asked Joe D. the question.
You have lowered the bidding from runaway warming to high climate sensitivity. But the Vostok records are also problematic for that assertion since it is undeniable that something other than CO2 is driving the temperatures in these records. How sensitive can the climate be when CO2 levels are more a lagged result of temperature changes than a cause? Schrag and Alley’s article is behind a paywall so I have no idea how they find high sensitivity in such records. Glassman’s article is not behind a paywall, and he shows that the solubility curve for CO2 fits the Vostok CO2 and temperature data, which seems like a pretty important point, and that CO2 increases in those records are a result and not a cause of warming, which is also an important point.
Regards,
Willis Eschenbach says:
June 9, 2010 at 9:51 pm
[I]”…… I think that at the scale we are talking about (a change of ~ 100 ppmv in the last 50 years) claiming that the causation runs in the direction of “temperature causes CO2″ is as nonsensical as claiming “CO2 causes temperature”.
Both of them run aground on the same reef – since 1959 the CO2 rise has been steady and monotonic, while the temperature has risen and fallen in fits and starts…….”[/I]
I have to agree.
Love this website – follow it daily and the technical content and insightful posts are the best in WEB. I ‘m a lay person and not well versed in statistics. I am though, an early retired business analyst and RDBMS designer so I’ve done my share of analysis in many facets of business, computing and science. Although Lon’s paper is beautifully presented and makes a good argument, I’ve always been skeptical of stated constructs that are utterly complicated, especially statistical exercises where correlations are made from data sets with acquisition methods and relationships that are so vastly different and massaged beforehand so they can translate to a correlation (Single local CO2 analyzer and Global satellite temperatures Anomalies???).
In my layman opinion, when it comes to timelines, raw data always tells a better story. I got curious so I went to the GMD Mauna Loa site (MLO) and downloaded all the data for both CO2 and temperature. If we want to make CO2 levels and temperature correlations why not take both datasets from the same site? Interestingly, the hourly temperature data at MOL is only available from 1977 to 2007, with 2007 being dismally incomplete, while the CO2 data set goes back to 1958, hmmm. Beings that I always like to use real data I did the charts below from 1977 to 2006. That’s all that is available for direct correlation.
By the way, the datasets are available here – My thanks to the folks at NOAA and MLO:
ftp://ftp.cmdl.noaa.gov/met/hourlymet/mlo/
and here:
ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt
My lay person methodology:
– Downloaded the CO2 data to Excel and did a graph of monthly average PPM percent increase with 1/1/1977 as the zero baseline.
– Downloaded all the hourly datasets for temperature and appended all of the sets into an MS Access database table.
– All bad readings (99.9) were converted to Null values. Access ignores Null values for grouping and averaging purposes. There were approximately 2,500 bad hourly readings in the data, out of a dataset of 262,968 records. I made no attempt to interpolate these, they were ignored.
-Ran a database query on the dataset grouped by year and month with simple monthly averages for temperature and dew point.
-Exported the results to excel and charted them
Here are the charts:
The first is the CO2 percent change we are all familiar with. It shows a CO2 rise of around 16+% in 29 years:
http://jsuro.smugmug.com/photos/897755527_J7654-O.jpg
The next one is the hourly temperature and dew point record averaged monthly (I did the dew point because I was curious):
http://www.josesuroeditorial.com/photos/897755539_4gvW9-O.jpg
And last is the percent change in temperature, again with a zero baseline at 1/1/1977, with an added polynomial trend (2 order):
http://jsuro.smugmug.com/photos/897755557_m6hNX-O.jpg
I fail to see any correlation whatsoever between CO2 and temperature in the real MLO data. Then again I’m a lay person, and my interpretation of this data might well be in grave error. You are all free to draw your own conclusions, and hammer me if you wish – I won’t be offended :).
Best,
Jose
Quinn the Eskimo says:
Well, okay…He didn’t quite predict it (as he noted in a subsequent post) but he did raise the possibility. At any rate, I don’t know of anybody in the scientific community who is predicting it, save some recent statements by Jim Hansen about what might happen if we really go to town on burning the available fossil fuel reserves. Hansen hasn’t to my knowledge discussed this in the peer-reviewed literature, so it is still unclear what his thinking is, but I from what I can make out his argument is that the reason a runaway hasn’t been seen in the past is that (1) there was probably not ever so RAPID a rise in greenhouse gases and this might overwhelm the biogeochemical feedbacks that can keeps things in check on longer timescales, (2) if you go back long enough (say, at least many hundreds of millions of years) then the solar output was lower and this would also have limited things. I think it is reasonable to be quite skeptical of Hansen’s argument (particularly since he hasn’t really spelled it out in the scientific literature) but I don’t think it can be completely dismissed out of hand by the sort of arguments that you make.
Schrag and Alley’s article is in Science should be available at almost any library. The reason that it is behind a paywall is that it is published in a scientific journal. By contrast, Glassman’s article is not published anywhere…It is just the confused ramblings of someone who has a website.
You (and Glassman) seem to have a fundamental misunderstanding of how the glacial – interglacial cycles are currently understood and how the climate sensitivity is determined from them.
First of all, the trigger is understood to be the Milankovitch oscillations in the earth’s orbit and axis of rotation. These affect the distribution of solar insolation in location and time of year, particularly at high latitudes. And, it is believed that when the summer sun is insufficient to melt high northern latitude snow then the ice sheets grow. Along with this and the resulting cooling due to the increase in albedo from the ice sheets is a drawing down of CO2 levels, mainly by uptake by the ocean. The warming is essentially the reverse process.
You also seem to think that scientists mistakenly attribute the change in climate between the last glacial maximum and now to the change in CO2 levels and thus compute a climate sensitivity. That is not correct. What they do is estimate the total change in radiative forcings (in W/m^2) and, using that, and the total change in temperature, they can compute a climate sensitivity in K / (W/m^2). Then using the fact that a doubling of CO2 produces about 4 W/m^2 change in forcing, they compute the climate sensitivity for doubling CO2.
The total change in radiative forcings includes the albedo change due to the changes in ice (both land and sea) and vegetation, the change in greenhouse gas levels, and the change in aerosol loading. (The Milankovitch oscillations alone don’t produce a significant change in global annual radiative forcing…They just redistribute the insolation.) The forcing due to the change in greenhouse gas levels is known quite accurately. The change in albedo and aerosol loading a little less so (although the aerosol loading term is understood to be pretty small). And, doing this computation actually suggests that about 1/3 of the temperature change is due to CO2 (and maybe 40% or so once you add in the other greenhouse gases), so there is plenty of room for CO2 to contribute even if it lags the temperature change initiated from the albedo changes. And, in fact, the greenhouse gases likely played an important role in synchronizing the climate change in the two hemispheres since without them it is difficult for climate models to reproduce the large temperature change in the Southern hemisphere.
Bart says:
June 11, 2010 at 11:42 am
Bart, how does the IPCC obtain the value adot = 4% of Co/tau ?
Jose:
At June 11, 2010 at 4:50 pm you quote and say:
“Willis Eschenbach says:
June 9, 2010 at 9:51 pm
[I]“…… I think that at the scale we are talking about (a change of ~ 100 ppmv in the last 50 years) claiming that the causation runs in the direction of “temperature causes CO2″ is as nonsensical as claiming “CO2 causes temperature”.
Both of them run aground on the same reef – since 1959 the CO2 rise has been steady and monotonic, while the temperature has risen and fallen in fits and starts…….”[/I]
I have to agree.”
Sorry, but that does not follow. I addressed this matter of
“the CO2 rise has been steady and monotonic, while the temperature has risen and fallen in fits and starts”
on the thread at
http://wattsupwiththat.com/2010/06/07/some-people-claim-that-theres-a-human-to-blame/
I copy here my posting that explained the matter.
Richard
*********
Richard S Courtney says:
June 8, 2010 at 6:11 am
Fred H. Haynie:
At June 7, 2010 at 6:20 pm you say:
“A more informative exercise is to use the Scripps seasonally adjusted monthly CO2 averages, convert to global gigitons/year (annual difference or accumulation rate) and compare the cyclic behavior to the relatively straight line for anthropogenic emissions. They average about the same but the natural cycles vary by orders of magnitude. This does not play well for cause and effect.”
With respect it is not true that “This does not play well for cause and effect”, but it does deny the CO2 ‘budget’ analyses used by e.g. the IPCC to determine “accumulation” of anthropogenic CO2.
Your comment pertains to the fact that the annual pulse of anthropogenic CO2 into the atmosphere should relate to the annual increase of CO2 in the atmosphere if one is directly causal of the other, but their variations greatly differ from year to year. This necessary relationship is because the direct causation would require that the carbon cycle were so near to saturation that the system could not sequester all the anthropogenic addition.
However, the rates of the seasonal variations to atmospheric CO2 concentration demonstrate that the system is not near such saturation.
(ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005) ).
A caveat is that the use of annual data for anthropogenic CO2 may be an error. Some data on e.g. fuel consumption may not be collated in time so may be misallocated to an adjacent year, so 2-year smoothing of the data is justifiable. And some countries may use different 12-month periods for their accounting years which – together with the reason for 2-year smoothing – provides justification for 3-year smoothing. But smoothing of the data over 4 or more years is not justifiable.
The IPCC uses 5-year smoothing to get the data to ‘fit’ its model of ‘accumulation’ of anthropogenic emissions to the observed rise in atmospheric CO2 concentration as determined at Mauna Loa.
However, in our paper that I cite here and outline at June 7, 2010 at 2:43 am above, we provided six models that each match the annual data for the anthropogenic emission to the observed rise in atmospheric CO2 concentration as determined at Mauna Loa. None of these models used any smoothing or other adjustment to any of the data. As I explained above (at June 7, 2010 at 2:43 am):
“Our paper then used attribution studies to model the system response. Those attribution studies used three different basic models to emulate the causes of the rise of CO2 concentration in the atmosphere in the twentieth century. They each assumed
(a) a significant effect of the anthropogenic emission
and
(b) no discernible effect of the anthropogenic emission.
Thus we assessed six models.
These numerical exercises are a caution to estimates of future changes to the atmospheric CO2 concentration. The three basic models used in these exercises each emulate different physical processes and each agrees with the observed recent rise of atmospheric CO2 concentration. They each demonstrate that the observed recent rise of atmospheric CO2 concentration may be solely a consequence of the anthropogenic emission or may be solely a result of, for example, desorption from the oceans induced by the temperature rise that preceded it. Furthermore, extrapolation using these models gives very different predictions of future atmospheric CO2 concentration whatever the cause of the recent rise in atmospheric CO2 concentration.”
This provides an apparent paradox. The annual anthropogenic emission of CO2 should relate to the annual increase of CO2 in the atmosphere if one is directly causal of the other but these two parameters do not correlate. But – using each of our different models – we were able to model the increase of CO2 in the atmosphere as being a function solely of the annual anthropogenic emission of CO2. And we did not use any ‘fiddle factors’ such as the 5-year-averageing used by the IPCC to get a ’fit’. (Adoption of that smoothing really is a disgrace. There can be no justification for it because there is no known physical mechanism that would have that effect).
The apparent paradox is resolved by considering the calculated equilibrium CO2 concentration values. These show an important difference between the three models. They diverge.
But each model indicates that, for each year, the calculated CO2 concentration for the equilibrium state is considerably above the value of the observed CO2 concentration in the air. This demonstrates that each model indicates there is a considerable time lag required to reach the equilibrium state when there is no accumulation of CO2 in the atmosphere.
The short term sequestration processes can easily adapt to sequester the anthropogenic emission in that year. But, according to our models, the total emission of any year affects the equilibrium state of the entire system. Some processes of the system are very slow with rate constants of years and decades. Hence, the system takes decades to fully adjust to the new equilibrium. And the models predict the atmospheric CO2 concentration slowly rising in response to the changing equilibrium condition.
Simply, we demonstrated that it is possible that the total natural flux of CO2 from the Earth to the air may increase over time as a response to increasing anthropogenic emission. And this provides an explanation of why the apparent accumulation of CO2 in the atmosphere continued when in two subsequent years the anthropogenic flux into the atmosphere decreased (this happened, for example, in the years 1973-1974, 1987-1988, and 1998-1999).
So, in summation, your observation does disprove the IPCC model of “accumulating” anthropogenic CO2 in the air, but it does not negate the possibility that the anthropogenic emission is responsible for the recent (i.e. since 1958) rise in atmospheric CO2 concentration. And our models demonstrate that the cause of the recent rise may be entirely natural, or entirely anthropogenic, or some combination of anthropogenic and natural causes.
So, a question:
Is the cause of the rise in atmospheric CO2 concentration natural or anthropogenic in part or in whole?
Answer:
God alone knows.
Richard