Yet more scientific backing for Air Con's main point

In the climate debate, we can choose to listen to truffle fanciers like Gareth at Hot Topic, journalists like myself or politicians like Al Gore, or one of the leading scientists in the climate field, like Roy Spencer from University of Alabama-Huntsville. The following is a fascinating essay from his blogsite, which backs up the central thesis in Air Con - most of the CO2 increase is natural, not man-made:

Global Warming Causing Carbon Dioxide Increases: A Simple Model

May 11th, 2009 by Roy W. Spencer, Ph. D.

Global warming theory assumes that the increasing carbon dioxide concentration in the atmosphere comes entirely from anthropogenic sources, and it is that CO2 increase which is causing global warming.

But it is indisputable that the amount of extra CO2 showing up at the monitoring station at Mauna Loa, Hawaii each year (first graph below) is strongly affected by sea surface temperature (SST) variations (second graph below), which are in turn mostly a function of El Nino and La Nina conditions (third graph below):

Click for larger images

Click for larger image

During a warm El Nino year, more CO2 is released by the ocean into the atmosphere (and less is taken up by the ocean from the atmosphere), while during cool La Nina years just the opposite happens. (A graph similar to the first graph also appeared in the IPCC report, so this is not new). Just how much of the Mauna Loa Variations in the first graph are due to the “Coke-fizz” effect is not clear because there is now strong evidence that biological activity also plays a major (possibly dominant) role (Behrenfeld et al., 2006).

The direction of causation is obvious since the CO2 variations lag the sea surface temperature variations by an average of six months, as shown in the following graph:

So, I keep coming back to the question: If warming of the oceans causes an increase in atmospheric CO2 on a year-to-year basis, is it possible that long-term warming of the oceans (say, due to a natural change in cloud cover) might be causing some portion of the long-term increase in atmospheric CO2?

I decided to run a simple model in which the change in atmospheric CO2 with time is a function of sea surface temperature anomaly. The model equation looks like this:

delta[CO2]/delta[t] = a*SST + b*Anthro

Which simply says that the change in atmospheric CO2 with time is proportional to some combination of the SST anomaly and the anthropogenic (manmade) CO2 source. I then ran the model in an Excel spreadsheet and adjusted an “a” and “b” coefficients until the model response looked like the observed record of yearly CO2 accumulation rate at Mauna Loa.

It didn’t take long to find a model that did a pretty good job (a = 4.6 ppm/yr per deg. C; b=0.1), as the following graph shows:

Click for larger image

The best fit (shown) assumed only 10% of the atmospheric CO2 increase is due to human emissions (b=0.1), while the other 90% is simple due to changes in sea surface temperature. The peak correlation between the modeled and observed CO2 fluctuation is now at zero month time lag, supporting the model’s realism. The model explained 50% of the variance of the Mauna Loa observations.

The best model fit assumes that the temperature anomaly at which the ocean switches between a sink and a source of CO2 for the atmosphere is -0.2 deg. C, indicated by the bold line in the SST graph, seen in the second graph in this article. In the context of longer-term changes, it would mean that the ocean became a net source of more atmospheric CO2 around 1930.

A graph of the resulting model versus observed CO2 concentration as a function of time is shown next:

If I increase the anthropogenic portion to 20%, the following graph shows somewhat less agreement:

There will, of course, be vehement objections to this admittedly simple model. One will be that “we know the atmospheric CO2 increase is manmade because the C13 carbon isotope concentration in the atmosphere is decreasing, which is consistent with a fossil fuel source.” But has been discussed elsewhere, a change in ocean biological activity (or vegetation on land) has a similar signature…so the C13 change is not a unique signature of fossil fuel source.

My primary purpose in presenting all of this is simply to stimulate debate. Are we really sure that ALL of the atmospheric increase in CO2 is from humanity’s emissions? After all, the natural sources and sinks of CO2 are about 20 times the anthropogenic source, so all it would take is a small imbalance in the natural flows to rival the anthropogenic source. And it is clear that there are natural imbalances of that magnitude on a year-to-year basis, as shown in the first graph.

What could be causing long-term warming of the oceans? My first choice for a mechanism would be a slight decrease in oceanic cloud cover. There is no way to rule this out observationally because our measurements of global cloud cover over the last 50 to 100 years are nowhere near good enough.

And just how strenuous and vehement the resulting objections are to what I have presented above will be a good indication of how politicized the science of global warming has become.

REFERENCES
Michael J. Behrenfeld et al., “Climate-Driven Trends in Contemporary Ocean Productivity,” Nature 444 (2006): 752-755.

Hat tip: WattsUpWithThat

Comments

[AcidComments]

"The best fit (shown) assumed only 10% of the atmospheric CO2 increase is due to human emissions (b=0.1), while the other 90% is simple due to changes in sea surface temperature. The peak correlation between the modeled and observed CO2 fluctuation is now at zero month time lag, supporting the model’s realism. The model explained 50% of the variance of the Mauna Loa observations."

Interesting.

Yeah. Man's only responsible for the least amount of CO2 emissions compared to Nature and here we're being blamed for 90% Climate Change. That's why the AGW Doomsayer Gurus are blowing hot air out both ends. They're either completely incompetent, liars, fraudsters or on a political agenda!

[Carol Stewart]

Ian, we can also listen to our own excellent New Zealand climate scientists, like Prof Martin Manning and Dr David Wratt. They disagree with your overall drift.

[DyannT]

I am currently reading "Solar Rain" by Mitch Battros. As a weather novice it makes a hell of a lot of sense to me. The chapter I'm reading at the moment talks about the link between the sun's cyclical behaviour and the La Nina and El Nino cycles. I have read very little reference to the Sun-Earth link in most discussions about us bad humans destroying the planet.

[Ian]

I devote a significant amount of space in Air Con to the sun's role in warming, Dyann, within the larger context of the climate change debate.

@Carol...the issue is not whether Wratt et al disagree with me - it's whether they have a more convincing explanation than people like Spencer.

I'm sorry, having read the IPCC reports and all the major studies since, I am more convinced than ever that warming is natural, for precisely the reasons I explain in the book...

[Shunda Barunda]

One things for sure, the science is not "settled".

[Carol Stewart]

Yeah, that's what the tobacco companies continued to argue.

[Ian]

Carol, it's really very simple. Gareth can explain on his blog why Roy Spencer is wrong.

You have shown a desire to argue the issues, and so we should. If AGW doesn't have a convincing answer, then you can take it as yet more proof that the AGW camp is trading mostly on rhetoric and slogans, not science.

Once you read Air Con, I suspect that will become blindingly obvious to you, because like everyone else who has actually read the book, you will see how Gareth's reviews utterly failed to deal with any of Air Con's main themes.

And that, Carol, is a sign of weakness in Hot Topic's position. In the book, the studies I quote are as recent as April 2009. In contrast, as you'll see when the latest Investigate comes out next week, Gareth's testimony to the ETS committee last month was out of date.

The AGW camp is quoting out of date science, and that should concern you.

[peter]

Carol

Did you realise how appropriate your comparison of Roy Spencer and the Tobacco Industry might be?

Why do I see a reference to this man on this site?

http://www.exxonsecrets.org/html/personfactsheet.php?id=19

Exxon Mobil indeed!

[Ian]

Peter, Exxonsecrets is a Greenpeace front...congratulations, you fell for it.

There's nothing remotely sinister in the references to Spencer on that site, so now let's deal with the science: Spencer's study suggests strong evidence that oceanic CO2 is the primary driver of increased CO2 levels in the atmosphere. (Looking at the graphs, very strong evidence).

Not a squeak out of Hot Topic and no one posting here challenges it.

Yet this goes to the heart of all those glib and simplistic slogans about C12/C13 ratios being a sure sign of AGW.

Really?

Read Air Con, you'll learn something.

[peter]

Ian

If this excellent Exxonsecrets site had been the only reference, I would not have included it. It was a trap and you fell for it.

Look at this link:

http://mediamatters.org/research/200605190003

I quote:

' Roy Spencer is the chief research scientist at the University of Alabama-Huntsville. As noted above, he and Christy released a study in 2003 that, using faulty calculations, purported to show that temperatures in the troposphere had remained constant over the previous two decades.

Like Michaels, Spencer also has ties to the George C. Marshall Institute. Beyond his criticism of global warming theory, Spencer has also taken up another cause that places him well outside the scientific mainstream -- his view that "intelligent design, as a theory of origins, is no more religious, and no less scientific, than evolutionism." '

My god Roy Spencer has been an intelligent design fan as well !!!

I rest my case.

[cj_nza]

"intelligent design, as a theory of origins, is no more religious, and no less scientific, than evolutionism."

A conclusion that I also reached after reading several publications by Dawkins.

[Shunda Barunda]

"he and Christy released a study in 2003 that, using faulty calculations"

Peter, I guess you were one of those applauding "an inconvienient truth"?
Perhaps you should go check on the acuracy of the science behind that load of bollocks.

[Ian]

Peter, if you had read Air Con, you would see that MediaMatters has been extensively funded by organisations promoting belief in human caused global warming.

It's 'claims' are bought and paid for.

[david w]

OK Ian, here is a simple question.

If you think that most of the recent increase in C02 has come from warming oceans (that's the idea right?) shouldn't they be losing CO2? Aren't they, in fact, acidifying?

And while we're at it, if most of the new CO2 is coming from the ocean, how is it that both the atmosphere and the ocean have decreasing 13C:14C ratios?

[Shunda Barunda]

Just watched the new documentary "Earth" with the wife and kids.

Wonderful piece of work.....except for all the propaganda at the end!!

No more polar bears by 2030 apparantly!.

[peter]

A very good appraisal of Roy W Spencer's advocacy of Intelligent Design is contained here:

http://blogs.salon.com/0001561/2005/08/09.html

He is so wrong about intelligent design that it is hard to take him seriously on climate change.

The graphs published by Ian are too simplistic to be of any real value.

Also look at this:

http://www.washingtonpost.com/wp-dyn/content/article/2006/05/20/AR2006052001151.html

' Spencer's serious academic work has sparked controversy. While at NASA -- between 1984 and 2001 -- he and University of Alabama at Huntsville professor John Christy pioneered satellite monitoring that indicated the Earth was warming more slowly than surface temperature readings would indicate. In 1991 the two researchers won NASA's Exceptional Scientific Achievement Medal for that work, but this month a government study concluded there was no statistical difference between the two climate records.

Spencer acknowledged that other satellite experts have found two errors in how he and Christy processed their data. '

So yes .. Spencer is a dag, and I love the photo of him playing guitar in a church band.

I don't think he is contributing much to the question Ian.

[maksimovich]

david w

Bomb

eg http://www.niwa.co.nz/__data/assets/image/0018/43452/Bhd_14co2_800.jpg

[maksimovich]

peter

Svante Arrhenius is also a "dag"

Interesting perspective on Racial purity and eugenics,

Also of interest is his views on the origins of life (it came from mars)

eg http://en.wikipedia.org/wiki/Svante_Arrhenius

[Bamm Bamm]

You just have to look at the gene pool in Auckland and realise it won't be long till the Government implements a Eugenics programme of its own.

[david w]

maksimovich,

Wrong carbon isotope I'm afraid. 14C is the one that us secular folks made up to support our creation fairy story. 13C is a stable isotope that we invented to add to our end-times myth.

Just re-reading the post that Ian reproduced I see that the 10% figure is not the percentage of CO2 increase to be credited to anthropogenic emissions - it the percantage of emissions that make it to the atmosphere! Where does the rest go?