Bishop Hill Vision of awfulness
May 31, 2013 Climate: sensitivity The Vision Prize describes itself an "an online platform for communicating expert opinion on climate risk" and seems to be essentially a fairly basic online poll.
I was intrigued by the way its experts assessed climate sensitivity. The relevant question was what the effect on temperature relative to the year 2000 will be if carbon dioxide concentrations reach 550ppm (i.e the first doubling, expected around mid-century).
Here are the results:
;)
The mode is 1.5-2.0°C. Given that this is temperatures relative to the present day, we have to add say 0.8°C to get the "climate sensitivity" figure, which would be 2.3-2.8°C. It seems to me that this figure is hard to justify if transient climate response is 1.3°C and effective climate sensitivity is 1.7°C, as seems likely from the empirical evidence.
Perhaps then the results are affected by climatologists who lie to promote political action.
Reader Comments (32)
Speaking of "visions of awfulness" - and of those who are exceedingly economical with the truth in order to promote political action ...
There are some rather familiar names (Mann, Gleick, Weaver, Hansen, Karoly, Ehrlich, and Suzuki) who have signed onto a "Scientists' Consensus" on "Maintaining humanity’s life support systems in the 21st century" which they call a "Summary for Policy Makers".
Details and links in update to my post:
Crisis of the week: the biosphere … new “Statement” percolated, circulated and endorsed
65% voted less than 2 deg C?
This from the Vision Prize site explains what 'actual' and 'expected' mean:
Another self-selecting set of academics preaching the religion. Noticed a steep fall off in older (more experienced?) participants.
http://visionprize.com/participants#leaderboard
these are climate experts so it's hard to underestimate their expertise - do they actually understand the point about 0.8C?
As I said, a set of government funded researchers wanting to keep their jobs.
Not the top of the list though :
"skywatcher
not provided; (United Kingdom); Other scientific or technical - commercial; Palaeoclimate, models, GIS; Industry - Environmental Services;"
Wonder how they assessed his/her expertise, no name, place of work or is he the 'skywatcher' troll thrown off many sites?
Wonder how many 'experts' like this there are?
Following the Briggs advice of 'just look at the data', here is a graph of the mode of the expert predictions alongside HADCRUT4, so that people can judge for themselves how likely the expert prediction is looking. I've taken the 'since 2000' literally, and 2000 was a cool year - if I had added the [1.5-2.0] to, say, 2001, the green bar would be higher.
I signed up. Surveys like these don't mean much, but there is some information there about current opinions. There is no "don't know" option, which increases noise, and self-assessed expertise is measured only indirectly.
@Paul Matthews
One simple graph that tells us all we need to know, nice work fella.
Can anyone sign up? You apparently dont even need to use a real name. What makes then experts? Self-selection?
Omnologos:
Ouch. But it made me laugh and this Friday that's expertise indeed.
Paul: It looks a bit like a game of Pong with one player bound to lose.
Since it's been pretty flat since 2000, the majority (over 60%) of these experts believe that temperatures are going to rise at > 0.4C/decade between now and 2050.
How can any one of them, let alone 60% of them, justify this?
@steveta_uk
There is a double filter. First, you need to prove that you're human. That's easy. Second, a human on their side checks your credentials. I got in within an hour.
The wording of the questions seems, as with many polls, intended to influence. For example, "If government policies do not change, in the year 2050, what will be the increase in global average surface temperature relative to the year 2000?" makes the suggestion that only governmental policy can effect a change in trajectory. Nothing about technological change. [Not that I'm particularly optimistic about there being a cost-competitive alternative to fossil fuels in the immediate future. But why not a more neutral phrasing?]
.
I find it interesting that there is a significant minority of respondents predicting US hurricane landfalls to double *in this decade*. The largest prediction category interestingly has the highest mean h-index. This certainly does evoke Annan's comment mentioned in the final sentence of the post.
According to this, fully 36% of their "experts" (is it clear how these are chosen or defined?) estimated under 1.5 degrees. Which would make them pretty mild luke warmers, if not outright sceptics.
Not exactly 97% is it?
As we are in soothsayer mode, let me make some predictions, with absolute confidence of the outcome: by 2050, the following events will have occurred:
There will be at least one large storm wreaking havoc on a major city;
Several countries will have heat waves, during which citizens will die;
Several countries will have periods of intense cold, during which citizens will die;
There will be at least one major earthquake, resulting in many deaths;
Several countries will experience extreme drought, with a variable death toll – generally, the poorer the country, the higher the toll – resulting in crop failure, and an increase in food prices;
Several countries will experience flooding, with a variable death toll – generally, the poorer the country, the higher the toll – as well as crop failure, and an increase in food prices;
There will be a glut of many crops;
There will be a shortage of many crops;
The concentration of CO2 in the atmosphere will continue to rise;
Global temperatures will change surprisingly;
Climates will alter;
All of the above will be attributed to “Climate Change”;
Several heads of state will die in office;
David Cameron will say something sensible (probably along the lines of, “Right, I’m out of here…”)
At least one politician will do something sensible;
The European Union will collapse.
(Admittedly, the last prediction is probably wishful thinking)
Finally, any or all of the above might not occur – though if any of the last three do occur, that will virtually guarantee the others will occur.
Ooh, a few others I haven’t included:
Arctic and Antarctic sea ice measurements will show record minimums;
Arctic and Antarctic sea ice measurements will show record maximums;
Sea levels will change.
@ RR
The corollary to your list must be that ecofascists can point to those incidents being unheard of in any other 37-period. If this is not true, then they have rather lost.
Your Grace there are a couple of things I need to get off my chest – starting with this bra……..aahhh that’s better. Now I can feel myself think.
This climate sensitivity thing. It’s a bit of a wheeze isn’t it? Cant be measured. All highly theoretical. Only purpose it serves is to keep the bed-wetters and tree-huggers awake at night.
If you step back for just one minute and ask yourself what does it mean? The increase in average global temperature in response to a doubling of CO2. Well the first thing that has a bit of a fishy smell is that reference to temperature.
Coincidentally when I was down the supermarket this morning I asked Eric on the fish counter if temperature could be averaged. If looks could kill! I will tell you what he said – I wrote it down word for word “Na, mate. You cant average tempture. You see tempture is one of them intensif qualities. And the fing abart an intensif quality is that it cant be averaged. You gotta take accarnt of enfalpy. Look, you know how the tropics is all hot and sticky and that. Well that’s cos its like high on enfalpy. But you go to the Norf Pole and fings is all different. Facking cold and that but the air there is really dry. So not much enfalpy ararnd. And you could have a fing where the average tempture of the tropics goes darn half a degree and the Norf Pole goes up a degree and the global average tempture has increased by half a degree but really the world has gotten colder cos there is overall less heat in the atmosfere. D’ya see?”
I did indeed see. And I rushed home to look up the meaning of enfalpy but alas it seems he was making it all up.
As I sat and pondered my lot I got a phone call. It was Uca from somewhere on the Asian sub-continent telling me I could claim £3000 on an old mortgage. I took the opportunity to ask Ucar if he knew how CO2 caused the earth to heat up. As it happens he was a mine of information. Radiative physics. Beautiful. Elegant. Short wave passes through. Longwave intercepted and boom! Heat where there was only light. I was impressed. But when I suggested that, in terms of the heating of the air at the surface, the oceans, convection, clouds and the hydrological cycle must be equally if not more important than his radiative physics, he hung up on me.
More or less immediately there was a knock on the door. It was Joe the post with a package for me. I do love shopping on Ebay. A beautiful pair of extra large silk stockings (15 denier!) for less than the price of a manicure. But I digress! As I was signing for the package I noticed it was sent by the ‘Costume Store’. CS I said to Joe. Does that have any significance for you? Not really, quoth he, unless you mean climate sensitivity? And before I could politely close the door to try on my new legwear, he was off and running.
“Climate sensitivity is the holy grail of the climate movement. You know all this ‘holding the rise to 2 degrees C’ and all that bollox. That’s all based on climate sensitivity. But between you and me I think it’s a scam. The whole concept of climate sensitivity is deeply flawed. I regard it as more of a political statement than a scientific one. Just a reason for the numpties in Westminster to tax us. But that’s just my opinion. Have a nice day.” And off he trotted.
Anyway, your Grace, now I’ve got all that off my chest, I can ask you the main question “Does my bum look big in this?
I do like a good laugh on a wet Friday afternoon!
If you have to ask if your bum looks big in it, whatever it is, then you already know the answer.
[Self snipped]
[Self snipped] ooo - sounds poinfull, missus!
A bit OT I'm afraid but I still don't understand the seemingly sharp contrast that is drawn between 'empirical evidence' and - what?- 'models'? What I think you mean by 'empirical evidence' is what I would call cruder models based on more simplifying assumptions, like the energy balance model the Nic Lewis has used very effectively. There's certainly some justification for simplifying, in that there are many difficulties in building, testing and interpreting more complex models.
I know many commentators here use the term 'model' differently, although I'm not always sure exactly how. I'm not interested in debating the 'real' meaning of the word, I'm happy for people to use it differently although it helps communication to be clear about how it is used. I would be interested in hearing what cut off people use in saying that a calculation is no longer 'empirical evidence' and has instead become a (suspect?) model. To me, building more sophisticated models is about trying to make more refined calculations and better approximations that account for more processes, constantly tested against data.
Simpler and more complex models seem to me complimentary. I just don't see this sharp contrast between 'empirical evidence' and the rest.
JK
I can't answer for other people but what I call empirical evidence is what happens in the real world.
What you get from looking out through that glass thing in the wall not the screen of that box on the desk which is churning out what you — in effect — told it to churn out.
I quite understand that models can be useful aids but to tell me that sea level is rising by xmm/yr because your models say it must be when in reality and according to measuring instruments it is doing nothing of the sort or when you tell me about the increase in violent storms when the actual figures for the last 30 years tell me something quite different my reply is "wake up and look at facts rather than data".
"What you get from looking out through that glass thing in the wall "
Mike, what in all you have read here gives you the impression that the Met Office has windows?
Rhoda, have a look:
http://www.ankerstjerne.co.uk/ankerstjernecouk/images/MET_Office_Layout-4.jpg
Rhoda
Just my natural blind faith and trust in human nature, I guess.
Would explain a lot, wouldn't it?
Steveta, I am shocked. You can use the windows to see where the money goes, I suppose.
Mike,
Surely the problem is that we cannot look out of the window and, for example, see what the global sea level is?
We can look at a gauge, or even many gauges around the world, or we could look at satellite data. But to turn that 'data' into a 'fact' takes calculations based on simplifications and assumptions.
Sometimes relatively simple models are sometimes the best, most insightful or most accurate we have. But so far as I can see they are on a sliding scale, not conceptually different to more complex models that try to take more factors into account to more accurately estimate sea level. There is not a sharp dividing line that turns 'empirical evidence' into a 'model'. And sometimes more complex models are better.
Very rarely is the very simplest model, e.g. taking the measure measurement of one gauge as our model of global sea level, the best. Taking our understanding of tidal variation, which is pretty good, and using it to build a model which subtracts out that variation will give a better answer. Trying to integrate data from a wider spatial range will improve it more, and so on.
I'm not saying the most complex models of sea level will be best, but I don't see that it is possible to measure sea level without using models in the sense I mean them. I would like to know 'what happens in the real world', but I don't see how to get there without theory and calculation. So while I agree that bad models should be ruthlessly criticized I still don't see the simple division between 'empirical evidence' and models.
Perhaps an example would be clearer. The original post refers to estimates that 'likely from the empirical evidence.' I said above that I take this to refer to estimates such as Nic Lewis' that I would describe as based on a simple energy balance model. Does anyone have another example of an estimate from 'empirical evidence' contrasted to 'models'?
JK
But looking at gauges is essentially "looking out of the window".
If you have, say, 1,000 gauges that have been in place for 50 years and you take readings every month you have 1000*50*12=600,000 readings or 12,000 readings a year for 50 years. Assuming (for simplicity's sake) that sea level is not season-dependent it should be easy to calculate the average monthly level and therefore the variation. If the levels are season-dependent then you have an additional calculation to make but none of this is beyond the scope of Excel, ie it's hardly rocket science and it doesn't need a model.
But a bit like our friend global average temperature there is in effect no such thing as "sea level" for all sorts reasons — different currents, different tidal ranges, different wind speed and direction, different air pressure in different places at different times.
To use a phrase I've already used today, it's like trying to knit fog.
So you shove all the possible variations you can think of into a big computer and call it a model. And if you've programmed it correctly it will come back with "insufficient data" because unless you have an accurate measurement for those five variations I've mentioned (and all the others I haven't thought of) any output will be meaningless as will any prediction about future sea levels.
And that's just sea levels! Where do we go next?
A question Your Grace,
do you believe CO2 is the main reason for global temperatures "rising"?
if the answer is no, why would rising CO2 levels cause global temperatures to rise?
climate sensitivity is a measure of how much rising CO2 levels cause temperature to rise.
so if CO2 is not causing temperature to rise there is no physical effect which can be labelled climate sensitivity.
this doesn't stop anyone comparing changes in temperature and changes in CO2 levels but the number they find doesn't mean anything. In particular if there is no direct link then estimates of climate sensitivity made at different times will be different, simply because there is no direct link.
The reason Adominer noticed things were fishy is because they are! - climate sensitivity does not exist.