Post here

Nicely done Rob.  I went in and made a few minor edits, but it looks good.  I like the snowball Earth image.  And I like that every time Salby's 'model' deviates from the data, he says the data must be wrong.  Denial 101!  It might be worth emphasizing that a bit more, in fact.  "Skeptics" are supposed to trust the data over the models, not vice-versa.

Some typos:

the atmsophere. (b) same - but for exchange of CO2 by ocean with atmsophere.

but therefater it deviates

he estimates atmsopheric CO2

in the air directly dependant upon temperature (dependent, I think)

increase in atmosperic CO2 is less

This is very good. Thank you. I think you got the tone about right. Some caveats may be in order since this rebuttal is based on an audio recording only. I'm confident that a written version would provide even more ammo but you never know for sure.

His incoherency with the 21st century increase in CO2 without a "causitive" increase in temperature is astonishing.

I know you had to limit rebutting all the arguments but how does he expain the uptick in CO2 coincident with the Industrial Revolution or does he just deny it because the ice cores are bogus?

What's driving the linear trend in CO2 increase if it's not us? How long has this gone on and how long will it go on? Is it cyclic?

What's his argument about isotopes? (I still haven't brought myself to listen to the podcast). If the CO2 is inorganic CO2 coming from the oceans shouldn't it be isotopically heavier and observable? I guess that's why he has to say that all the extra CO2 comes from the biosphere. 

There's a fundamental problem in that he looks at the derivative (the accumulation rate) rather than the simple accumulation. A steady rate of increase shows up only as a small ampliude DC shift when you look at derivatives. This is reminiscent of the infamous McLean et al ENSO paper. It's like observing a bobbing cork in the ocean and denying tides. You filter out the trend, fit a model to the residual and then integrate the model. King Canute lives! You might not have seen my comment here, comparing the US defict to FOREX flows.

I agree with Dana, that his placing of the model above mere data is very telling and should be highlighted. Skeptics are always telling us that AGW alarmism is model driven but the converse is true.

BTW, I'm now convinced that this not a hoax. It's definitely a farce, though.

Andy - typos fixed thanks.

CO2 & Industrial Revolution is not discussed, IIRC. He discusses the isotopic signature, but he keeps referring to graphs and it's difficult to work out what he's talking about. He never discusses where his 'magical CO2' might be coming from, and none of the geriatrics (by the sound of them) in the audience, grills him on all these obvious issues.

As for the accumulation rate, that should be the focus of an advanced rebuttal (sounds like Dikran is keen on a response to the journal publishing Salby's work). I tried to keep this as more an intermediate version that was accessible to the layperson, and tried to keep it brief as possible. By explaining the fast carbon cycle basics, one can see that Salby's claims are ludicrous. Well, that's my intention anyway.  

Dana  

Added a bit to accentuate Salby contravening 'skeptic lore' on model-bashing.

Thanks guys.

Good article. Not sure about the last little snipe about Salby living in Fantasia. We don't need to stoop to their level.

What do you think of opening the article by mentioning that humans are emitting 30 billion tonnes of CO2 into the atmosphere every year. This is a concrete, tangible fact that readers can get their head around and really puts his mathurbation in perspective.

Amended as suggested JC, good point about the 30 billion ton figure. Got rid of the snark at the end - hard to let go of anger when rebutting some of the more stupid "skeptic" memes.

I liked the post as well.

One phrasing that didn't work for me was: "As discussed in the first paragraph of this post (and evident in Figure 1), the natural flux of CO2 in and out of natural systems varies from year-to-year, and is 20-30 times larger than the annual contribution by humans, but this balances out in the long-term." Figure 1 doesn't show that latter point, as far as I can tell, and if so then I'd use a different conjuction or start a new sentence with something that makes that point.

I was wondering if it was worth a paragraph explaining that we have good theoretical reasons to EXPECT that the oceans and plants/soil/land-system would be net sinks over time as an initial response to our pumping additional CO2 into the atmosphere. I.e., instead of just saying "... by elementary deduction, the excess must be going into the oceans, forests and soils, the other components of the fast carbon cycle. This is confirmed by measurements...", but also saying that there are good reasons to expect this as well, at least initially.

I uploaded a scan of Tyler Volk's Chapter 8 from CO2 Rising. Check pages 143-144 for a nice non-technical discussion of why physics essentially dictates that the ocean should respond as a sink, and CO2 fertilization would be expected to drive the same response from the terrestrial biosphere. From his concluding paragraph:

"We now have reasons why there might well be net flows of CO2 from the atmosphere to the ocean, and from the atmosphere to the plants. That such net fluxes exist has been confirmed by experimental measurements..." 

Frankly, it drives me nuts that you are even having to respond to Salby, and it drove me even nuttier seeing the "denial of algebra" evident at Curry's. But it just seems to me that for an impartial reader with questions, it might be nice to provide some cursory theory as to WHY we might expect the oceans and plants to be natural sinks, rather than just making a deductive case.

As an aside, Volk has a very accessible style in describing the carbon cycle. He is also referencing Canadell (2007), Friedlingstein (2007), etc., but he walks the reader through it very effectively. Archer's book is also very good.

Would be nice to post this one tomorrow if possible, while the story is still relatively new.  Let me know when you're ready, Rob.

John's right, it's 30.6 billon now:

IEA CO2 Emissions Update 2010 - Bad News

For a bit of gratuitious cross-promotion, link to Dana's post:

Every year humans release around 30 billion tons of carbon dioxide (CO2) into the atmosphere through the burning of fossil fuels, such as coal and oil.

I've set up the rebuttal for this:

http://sks.to/salby

Rob, if you're happy with your blog post being used as the rebuttal (or want to tweak it), please Add A New Rebuttal. If you do, I'd suggest adding a green box at the end of your blog post saying:

This blog post has been used as a rebuttal to the climate myth "Murray Salby finds CO2 rise is natural" which can be found at http://sks.to/salby

Rusty - good point about the scientific expectation regarding carbon sinks . I've amended the text under the last heading, trying to keep it brief.

JC/Dana  -actually I'd link to a lot more SkS posts, but they're often not exactly easy to find. The hyper-link now goes to Dana's post.

Dana, ready when you are.

JC - I note you posted about the same time as my last post, which is why I didn't see it. How does one add the green box?

typo? "apparently has a upcoming paper that"
- an upcoming paper

I got it covered, Rob.

Deltoid has a post with a reply from Salby. It seems that his slides can be viewed on a video feed:

So the only way to see the slides is to watch the broadcast here at 6:30 am, 11:28 am, or 4:25 pm on Saturday 13 Aug (Sydney time)

Perhaps someone with the inclination and the ability could attempt a screen capture of this broadcast.

That's the same reply I got to my email enquiry

"The observed behavior is what it is."

well quite Murray, have a closer look ;o)