2011-04-21 09:24:46Hansen's latest paper on climate sensitivity with some interesting latest on ocean heat
John Cook

john@skepticalscience...
124.187.72.92

Hansen has a new paper out:

Earth's Energy Imbalance and Implications

This caught my attention in the abstract:

A recent decrease in ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols and a deep prolonged solar minimum.

What?!?! A 20 year delayed reaction to Mount Pinatubo. Okay, Hansen is a legend, way ahead of the curve on most things, but that sounds like crazy talk! I haven't had a chance to look at the paper in great detail but after a quick skim, here are a few highlights:

Section 9.2 (page 28) is the interesting part of the paper where he talks about ocean heat uptake (I'm sure James will find the earlier sections on fast and slow feedbacks interesting too). He referenced a von Schuckmann 2011 paper with the latest Argo data but googling it only found this abstract. However, I also found this Workshop Presentation in 2010 where they presents the latest ARGO data. Take-homes - a statistically significant global heat balance of 0.6W/m2 over 2005 through 2009 (page 19) but they caution the time frame is too short to conclude climate trends. Both these messages contradict the denier meme that the ocean is cooling therefore disproving global warming.

Hansen's Fig 14 shows how recent heat uptake is less than the trend over 1993 to 2008. In Section 12, Hansen talks about Trenberth's missing heat - he says according to his analysis, there is no missing heat.

I like this paragraph in Section 13.1:

A verdict is provided by the ocean heat uptake found by von Schuckmann and Le Traon (2011), 0.42 W/m2 for 2005-2010, averaged over the planet. Adding the small terms for heat uptake in the deeper ocean, warming of the ground and atmosphere, and melting of ice, the net planetary energy imbalance exceeded +0.5 W/m2 during the solar minimum.

This dominance of positive climate forcing during the solar minimum, and the consistency of the planet's energy imbalance with expectations based on estimated human-made climate forcing, together constitute a smoking gun, a fundamental verification that human-made climate forcing is the dominant forcing driving global climate change. Positive net forcing even during solar minimum assures that global warming will be continuing on decadal time scales.

Bill McKibben will like Section 13.4:

Earth is out of energy balance by at least 0.5 W/m2. If other forcings are unchanged, atmospheric CO2 must be reduced 30 ppm, to a level approximately 360 ppm, to increase Earth's heat radiation to space by 0.5 W/m2.
However, the measured energy imbalance was 0.59 W/m2 in 2005-2010, during a deep solar minimum. We estimate the energy imbalance averaged over a solar cycle as ~ 0.75 W/m2. In that case, CO2 would need to be reduced to about 345 ppm to restore energy balance, if other factors are fixed.

2011-04-21 09:48:36
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Reading it now

2011-04-21 12:05:20
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Hi John,

That PPT presentation by von Shuckmann is a great find!  Re some recent skeptic papers, cough, the conclusion slide states this:

"Since the sensitivity tests have revealed that further uncertainties are likely to

exist, the main conclusion includes that the global Argo data set is not yet long

enough to observe global change signals and currently, global indicators cannot be

interpreted as long-term climate signals."

It is very interesting how the trends in OHC change when one includes data from below 700 m.

Not sure what to think about the Hansen paper yet.  Maybe you should let him know about the von Shuckmann results, or I can, but someone ought to tell Hansen about this.

The Knox and Douglass  and Loehle's work has just been blown out of the water, so to speak.  Hey maybe that can be the title for a post ;)


2011-04-21 12:14:02Hansen & von Schuckmann
John Cook

john@skepticalscience...
124.187.72.92

Hansen references the 2011 von Schuckmann paper, that's what clued me to the paper in the first place. So Hansen is all over the latest data on the planetery imbalance.

Take-home re Loehle, Knox & Douglass - they always concentrate on short periods and just the top 700 metres. You need to go down to 2000 metres for a fuller picture and longer time periods to make meaningful statements about climate. In other words, they cherry pick both time frames and coverage - and deny the full body of evidence showing ocean warming to greater depths.

Yes, we should do a post about this. Pielke Sr is always saying (with some justification, I tend to agree) that ocean heat is the best measure of global warming. Hansen's take-home point - even during the solar minimum, the planetary imbalance is around 0.5 W/m2. Over the whole solar cycle, it averages out to around 0.75 W/m2. Global warming is still happening, peeps.

2011-04-21 12:23:20
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Oh dear, sorry John....Dr. von Shuckmann is a co-author for goodness' sakes! Major face palm-- that was really slack on my part! And that is what happens when you try and juggle too many things-- cooking dinner, putting children to bed, talking to wife, sneaking on to SkS....

So before I make even a greater fool of myself, I should read Hansen et al. in full instead of reading bits here and there.

 

2011-04-21 13:05:41Extra! Read all about it!
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

"Missing heat argument torpedoed"

2011-04-21 15:17:34
Ari Jokimäki

arijmaki@yahoo...
192.100.112.202

I'm quite puzzled about Hansen making these draft papers publicly available before peer review. Surely he knows that he is so prominent figure that many people will take these papers as truth without realizing that they might change considerably during peer review process.

2011-04-22 03:13:08Pinatubo rebound
Riccardo

riccardoreitano@tiscali...
93.147.82.173

John

the time length of the rebound after Mt. Pinatubo is determined by the response time of the planet, roughly a decade. It's not a big effect and it did not last up to today. Here he's playing with the details, a few tenth of W/m2; but it's enough to explain the current flattening of the imbalance.

By the way, I found interesting the idea of using the Green's function method to solve the energy balance equation, with the trick of pluging in a suitable response function. A nice improvement but still simple enough to run it countless times.

2011-04-22 03:37:16
nealjking

nealjking@gmail...
84.151.42.218

Riccardo,

Interesting comment on the Green's function method.

I guess it should be OK as applied to forcing but not to causes, because forcings add up linearly, but the total forcing is not linear in the component causes.

2011-04-22 04:00:59
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Oooh, Riccardo said that Hansen used a "trick"!  Sadly some might try and claim that Hansen must be deceiving us, that would be completely wrong of course.

Seriously though, I'm sure that Dr. Hansen would welcome some constructive critique from people here.

2011-04-22 07:22:36
Riccardo

riccardoreitano@tiscali...
93.147.82.173

neal
actually Hansen is just solving the standard heat balance equation, something like what Tamino did in his post "get real" with the solution as an integral function. The difference here is that it allows a more general behaviour than a single response time.

Albatross
I often use the word trick in my daily work, so yes Hansen used a trick! and a very clever one, indeed :)

2011-04-22 09:11:20
nealjking

nealjking@gmail...
84.151.42.218

Riccardo,

Yes, any linear time-invariant system should behave like that.

My point is that it is OK to superimpose the effects of different FORCINGS that way; but you can't superimpose the effects of (say) CO2 with H20 with ozone... etc.... that way. Because the forcings are not linear in the component gas concentrations; in general the forcing is not linear with concentration anyway, but the situation is particularly tricky when the components' absorption spectra overlap, as the forcing due to A plus B is not the forcing of A plus the forcing of B.

2011-04-22 09:24:01
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Riccardo,  

Just to be clear, I was being facetious.  I should have finished with a "winky face".

2011-04-22 11:22:29Winky face
John Cook

john@skepticalscience...
124.187.72.92
Doesn't matter if you use a winky face, Alby. When this forum gets hacked by deniers and select quotes are posted on WUWT, they would've deleted that part of your post :-)
2011-04-22 11:24:48
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

That's why I try to put mine in bigger font so the quote miners wouldn't miss them...

2011-04-22 20:43:00
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.197

"Yes, we should do a post about this. Pielke Sr is always saying (with some justification, I tend to agree) that ocean heat is the best measure of global warming."

 

 

John: it seems the most sensible way of doing it. But we can't measure it easily...

 

But we can. In a way. Sea level pretty much tells us the total heat plus ice melt!

2011-05-02 23:24:29
James Wight

jameswight@southernphone.com...
112.213.139.45

Contrarians are using this paper to argue the science isn’t settled:

http://www.abc.net.au/unleashed/1031292.html

2011-05-02 23:47:01
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

"Niche Modeling" is influential?  Never heard of it.

 

Cox and Stockwell miss the main point of Hansen's paper: that GCM's are not correctly set up to model aerosols (also needing a bit of tweaking as to OHC, but that is more wecondary).  We are striking a Faustian bargain with our climate with the onslaught of CO2 AND aerosols we continue to inject into the atmosphere and carbon cycle.  The primary reasons the aerosol load has managed to keep the brakes on the temp response to the effects of the CO2 increase is both the shading effect of the aerosols, the CO2 uptake of the system and a quiescent sun.

Should these factors begin to change, the whole balance will be thrown out of whack.  A resurgent sun drives more Arctic melt causing a large albedo flip previously not a factor, more Arctic heating ensues causing more permafrost and hydrate melting, releasing more CH4 causing more heating.  The heating & GHG increases will further acidify the oceans, at some point degrading their efficiency as a sink, ramping up GHG concentrations, further driving up temps (and SLR), etc.

Our compact is with the devil; at some point there will be hell to pay,...

2011-05-03 03:52:37
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

I love the pejorative opening line from ABC essay:

"At his online website, free from the restraints of peer review,....."

They always have to suggest something nefarious is going on?  Hansen is being transparent, looking for input from anyone concerned and fully intends to publish the paper in a reputable peer-reviewed journal.  They also forget that the paper may change a lot between this draft version and the version that appears in print.

 

"Hansen notes the dramatic slowdown in heat uptake since 2003"

That hyperlink doe not link to work by Hansen,but to the meaningless Knotts and Douglass paper.  Note Hansen says "slowdown" (not dramatic slowdown) and not "cooling" as Knox and Douglass claim.

 

and 

" demonstrated by an international array of Argo floats, and also seen in a decrease in the rate of sea level increaseto 2.3 ± 0.5 mm/year from 3.1 mm/year"

That links to the disputed Houston and Dean paper.  What is worse, they suggests that the rate of se level rise has decreased from 3.1 to 2.3 mm/yr.  This statement flies in the face of the findings by Church and White, and the satellite altimeter data.

 

 

"But Hansen does not question the magnitude of warming from CO2 despite recent measurements showing CO2 heating may be saturated. Indeed, the need to increase the cooling of aerosols comes about because of the large positive forcing from CO2 is held constant."

Two myths there, saturated argument and that the aerosols are some kind of fudge factor that "need to be increased".

 

"A sceptic would point out that the effects of CO2 and feedbacks are also unmeasured, and another way to bring the energy into balance might be to reduce the presumed warming effect of greenhouse gasses."

Presumed warring effect?! 

 

"If agreement is based on flawed assumptions that are never experimentally tested, then agreement means very little."

Oh dear-- I have no idea what they are trying to imply?  that the radiative forcing of GHGs has not been tested experimentally?  That the warming of global temperatures and loss of ice from the cryosphere is imaginary?  There is more empirical evidence out there than you can shake a hockey stick at for God's sakes.  I could not stomach going through the whole diatribe.

Now John or someone else requests an editorial to counter this nonsense, and voila, we have faux debate and inflated uncertainty.

And they have the gall to say:

"Honest Jim: the science is not settled"

Honest?! They have very deftly managed to twist and distort Hansen's work and misrepresent the science.  I am going to email Hansen about this.

2011-05-03 06:46:18
Alex C

coultera@umich...
67.149.101.148

On a positive note, Cox and Stockwell don't seem to have a WUWT-style audience.  Quite the opposite, the comments below seem to all tear them apart.