Saturday, December 14, 2013

Has the puzzle of the 'hiatus' been solved?

An article in the Guardian today reports about a meeting between members of the Royal Society and the Global Warming Policy Foundation which took place in November. There is no official record of the meeting; apparently there was an agreement to keep it secret. Lord Lawson had written a short article for the Spectator. What was said by whom is now becoming a topic of public interest, not only in the blogsphere but in the mainstream media.  The Guardian reports about the background to this:

It was a summit of sorts, but certainly not a meeting of minds: at 10am on 19 November, six of Britain's most eminent climate change scientists entered a wood-panelled committee room in the House of Lords to face the country's most prominent climate change sceptic, Lord Lawson. 
The scientists had originally understood the meeting to be a private briefing for the former chancellor, following a spat between the peer and Professor Sir Paul Nurse, the Nobel prize-winning biologist and president of the UK's elite science academy, the Royal Society
Over the past year, Nurse has accused Lawson of cherrypicking global temperature data to claim that climate change has stopped over the last 15 years. The peer called the charge "a lie".
Nurse then offered to put Lawson in touch with "distinguished" scientists who could provide the "highest quality" climate science and the meeting was arranged.
During the meeting the so called 'pause' or 'hiatus' in global warming was discussed.
Professor Sir Brian Hoskins, of Imperial College London, said: "There was not any major disagreement on the science we presented, which is an interesting thing."
In particular, Hoskins debunked the so-called warming "pause", describing how excess heat has continued to be trapped by greenhouse gases for the past 15 years, showing that global warming is continuing.
He said air temperature alone is a very limited view of climate change, given that 93% of all trapped heat enters the oceans.
"I can't remember any challenge of that in the meeting," he said.
Hoskins, like his five colleagues, is a fellow of the Royal Society, the highest honour conferred on scientists in the UK, and all are active in climate change research.
The GWPF's 10 representatives included only one climate scientist –Professor Richard Lindzen, from Massachusetts Institute of Technology – who Lawson describes as "arguably the world's most eminent climate scientist".
(The Guardian is quick to remark that Lindzen is outside the 97% consensus of climate scientists).

Three aspects are remarkable. First, the offer to 'educate' Lawson by some distinguished scientists. Second, the 'debunking' of the 'pause' through the explanation of heat being trapped in the oceans. As far as I am aware there is no accepted explanation for the 'pause' at the moment, not in the latest IPCC report (which is normally quoted as the 'highest quality' science), and not in climate science generally (see Hans von Storch and Eduardo Zorita's recent posts here on Klimazwiebel). Third, Brian Hoskins seems to claim that this explanation had been accepted by the skeptics present at the meeting.

All three aspects are part of one big problem which seems to attract a lot of energy and interest, not only within climate science. It would be good to have more transparency on the matter, rather than selected media bites which are spun in specific ways.


Papa Zu said...

A fourth takeaway for me is the request that the meeting discussion be kept secret. I've spent much of my life watching corrupt Chicago politicians exposed for meeting in secret and closed door deals. Is it asking too much that scientists not mirror the actions of corrupt Chicago politicians and instead choose transparency?

Anonymous said...

I do not think ONE tiny blog is the blogsphere. That is an interesting choice of words. Grundmann should be more careful.

What is "GPWF"? a YASTT?

Anno Ny. Mouse.



MikeR said...

Asking for clarification from the experts: If the "missing heat" did disappear into the oceans. The oceans are much colder than most of the atmospheric system, so presumably such a transfer is pretty much one-way. Does that mean that we have gained fifteen free years on climate change, where the extra heat vanished into a till-now-unknown hole? Or does it not really help much, because at any time (when the effect ends) the temperature will hop all the way up where it "should be" based on the CO2?

Ben said...

Opposing "climate change scientists" and "climate change sceptics"? What kind of science is this? Sounds like racism to me.

Ben said...

If the "missing heat" did disappear into the oceans, it must have done that since oceans exist. So it is accounted for in the observed land and sea temperatures and doesn't suddenly create a hiatus.
Were there any scientists in the meeting room?

matt said...

Ben, good point. We're missing a mechanism. What changed 15 years ago to increase the heat going into the oceans and reduce the rate of atmospheric temperature rise? We're also missing the consequences. Will it continue? Does it buy us time? How should it affect policy?

Anonymous said...

Earlier in the year there was the RSclimate event, the audio is now online, and the debate around hiatus, featured quite strongly, Prof Mike Hulme asks a very goosd question (~40 mins, 30secs) , whether reframing away from global surface air temperature will fly.

Also the Met Office's Julia Slingo, suggested to pause could continue...

44 mins 50 secs)

“’ve argued very convincingly and I say (said) it’s a great presentation about 15 years being irrelevant, but I think, some of us might say if you look at the Pacific Decadal Oscillation and it’s timescale that it appears to work, it could be be 30 years, not out of the woods yet, on this one”

There is a Bishop Hill article at the time by 'Katabasis' who attended (comments are interesting)

Barry Woods

Anonymous said...

There were 15 speakers at RS
Climate and very frank discussion/disagreement, were had (especailly in the Q/A at the end of each speakers talk.)

all the audios are here, click on each speaker to find the audio:

Mr John Ashton CBE, Grantham Institute for Climate Change, Imperial College London, Uk

Dr Olivier Boucher, Laboratoire de Météorologie Dynamique, France

Professor Mat Collins, University of Exeter, UK

Professor Dennis Hartmann, University of Washington, USA

Professor Corinne Le Quéré, Tyndall Centre, University of East Anglia, UK

Professor Jochem Marotzke, Max Planck Institute for Meteorology, Germany

Professor David Randall, Colorado State University, USA

Professor Ted Shepherd, University of Reading, UK

Professor Thomas Stocker, University of Bern, Switzerland

Dr Peter Stott, Met Office Hadley Centre, UK

Dr Julienne Stroeve, University of Colorado, USA

Dr Peter Thorne, Nansen Environmental and Remote Sensing Center, Norway

Professor David Vaughan, British Antarctic Survey, UK

Dr Gavin Schmidt, USA


Anonymous said...


As a doctors husband, hm, I mean layman, I think the heat transfer between ocean and atmosphere is a little bit more complicated than this. For one thing: the sun warms the surface (ocean, land), because the atmosphere is more or less transparent to sun light. (Notable exceptions like Ozone aside) The surface warms the air. Not only the sun radiation exists, but IR radiation exists that also warms the ocean. The IR radiation is caused by clouds or for example, greenhouse gases.

of course, it is much, much, much more complicated with all the wind, ocean layers, El Nino/La Nina, ice cover etc. I cannot explain it --> layman. Maybe the climate scientists can explain it.

Anno Ny. Mus.
PS: heat does not disappear.
PPS: @Ben: your comments are really not very helpful. It is hard to be nice.

Ben said...

"The IR radiation is caused by clouds or for example, greenhouse gases"
IR radiation comes from the sun, thus from the absence of clouds. Radiation from sun penetrates and heats the sea surface to a depth of several tens of meters.
Radiation from GHG lies in a different spectrum and penetrates at most to a few centimeters.

Anonymous said...

back radiation is in IR. Most energy from sun comes in the visible range. So what?

GHG still warms the ocean, no matter how deep its radiation penetrates. There are lot of papers about it.

Anno Ny Mus

Pekka Pirilä said...

About half of solar radiation that reaches the surface is visible light (a little less or a little more depending on the maximum wavelength included). 3% is UV and the rest near IR.

The amount of LWIR from the atmosphere to the surface is about twice the total radiation from the sun, LWIR emitted by the surface is still stronger.

Most of the solar radiation is absorbed in the top 1m of the atmosphere, about 40% penetrates deeper. The absorption is so strong in the top 1m, because a very large fraction of near IR is absorbed in that, while most of visible light penetrates somewhat deeper, and a small fraction hundreds of meters deep.

Almost all absorption and emission of thermal LWIR occurs in the top 0.1mm.

eduardo said...

The explanation of the increased heat up-take by the ocean could go, in a simplified form, as follows: In a steady state the ocean is heated from above, as Pekka explained, by short wave and infrared radiation. Part of this heat is radiated back upwards and part is distributed into the deeper ocean. Surface waters are thus generally warmer than deeper layers. If we increase the warming at the surface by increasing the solar radiation or the greenhouse radiation, the surface waters will warm- a trend in the surface temperature will be observed. Part of this 'excess' warming will be also distributed into the deeper layers, which will also warm. If at some point for some reason, the water column is stirred more vigorously or other mechanisms causes a stronger vertical mixing, colder waters will more frequently replaced the warmer surface waters and, conversely, cold deeper water will be replaced by warm surface water. The net effect is that the warming at the surface will slow and the warming in the deeper layers will accelerate - a temperature hiatus at the surface. The net heat up-take will also increase, since the heat loss by upward infra-red radiation from the surface also slows down

It is true that we need a factor that changes in the vertical mixing of the ocean - but this is quite difficult to be directly detected.

Ben said...

"If we increase the warming at the surface by increasing the solar radiation or the greenhouse radiation, the surface waters will warm"
Solar radiation is naturally modulated by the sun and by clouds, there is no anthropogenic "we".
Greehouse radiation is negligeable compared to solar radiation and only penetrates the water surface by millimetres. The little energy that is thus transmitted by greenhouse radiation is rapidly lost to convection and evaporation at the surface.

The question then is: why is the warming of the global oceans (0-2000 meters) over the past 10 years limited to the Indian and South Atlantic Oceans, when carbon dioxide is said to be a well-mixed greenhouse gas, meaning all ocean basins should be warming?

Pekka Pirilä said...

The GH warming of the surface is very far from being negligible as its about 2/3 of all energy to the surface. It need not penetrate at all deeper to the deeper water as its role is to compensate part of the energy lost by IR emission from the same layer. Without downwelling IR radiation from GHGs the surface would cool very rapidly by tens of degrees.

As a fraction of solar radiation penetrates tens and even hundreds of meters in the atmosphere, the oceans would be warming quite rapidly unless almost all that energy would be brought to surface and then transferred out from the surface by emission, evaporation, and conduction/convection.

The more GHGs we have in the atmosphere the higher must the surface temperature be to release as much energy as the ocean receives by radiation (SW and IR). The higher the surface temperature, the more of the energy from solar SW remains to heat the ocean.

Ocean currents may lead to net heat transfer from near surface to deep ocean. That's perfectly possible, but determining the actual rate of such heat transfer is not easy. As the large scale currents have an important role in the heat transfer, it's to be expected that the warming of the oceans is not uniform. Natural variability makes it still more difficult to tell, what has followed from increased GHGs.

Anonymous said...

Would warming of the surface layer not actually impede vertical ocean currents (and thus heat transfer) due to the increased density gradient?

Merry Christmas, BTW :)


eduardo said...



yes, that is correct, but there are other mechanism that also drive vertical mixing, like winds, waves, tides, flow over complex bottom topography, etc. If these change, vertical mixing can also change.

In my previous comment I was trying to show how increased vertical mixing could explain a stagnation in the surface temperatures. I did not say this is 'the explanation', and at this point I personally I do not think it is, at least not the sole explanation

Hans von Storch said...

I think we are in the middle of the puzzle-resolving process.

This means, normally, that we first try to screen which possible explanations we can construuct, and there have been suggested quite a few, from an inadequate analysis of the temperature record, to CFC reductions, so far underestimated ocean processes, underestimated effect of solar output, underestimated natural variability. The process of generating possible alternative explanations is - for me: likely - not yet over. Then a process will start to sort out the plausibilities of the various mechanisms, and it may very well be that we end up with a mixture of explanatory causes (my personal guess: a little more sun, a little less sensitivity) - and finally the IPCC will arrive on the scene, and assess the scientific literature. [Since hardly any material was available at the time of the cut-off of AR5, IPCC could not do a lot about it.]

Since it is an issue with high public attention, some scientists will try to push for "their" explanations, because they think they are "right", even if a little egocentric bias may be involved.

However, we are in a post-normal situation, where uncertainty is large, stakes are high, values involved, decisions urgent - then the solving of the puzzle becomes a political must, which means - the interested parties push for an explanations which is right for their agenda.

science needs some time fore examining the various possible explanations.