Submitted by Dr. Clive Best
The first IPCC report in 1990 chaired by Prof. Houghton made a prediction for a rise in global temperatures of 1.1 degrees C from 1990 until 2030. This prediction can now be compared with the actual data as measured up to now (May 2011).
Figure2: Comparison of yearly HadCru & UAH data with IPCC 1990 predictions
These results have been derived as described below. You can see the results here
http://clivebest.com/blog/?p=2208
regards
Dr Clive Best
Would I be correct in assuming that policy decisions are being made on the assumption that volcanoes will no longer erupt or that the Sun will remain steady for the next 89 years!? This is insane (unless I’ve missed an important point).
The analysis is not relevant. Observational data is not relevant. All thatmatters is that the models continue to show that the results are worse than previously predicted.
Get with the programme. Please !
It’s not tentative. It’s contingent. If you eat a 5000 calorie diet of lard for a year, you will put on 50 lbs. That’s not tentative. That’s a conditional prediction. As Far as what the Met Office says, its NOT a matter of offsetting ALL the effect of C02. But if you are going to test a prediction you must take certain effects into account. Like a huge dip in temps due to a volcano. So, if instead of eating 5000 calories a day you eat 4000, and you excercise 500 calories per day, you really cant test the claim “If you eat a 5000 calorie diet of lard for a year, you will put on 50 lbs” If you ate 4000 and exercised 500, and only put on 38lbs, what can you say about the original forecast?
not much.
Well jimbo, In Ar4 they ran models forward with a HIGH solar forcing. You could run them with both extremes.
For volcanos, its simple. The average over 100 years doesnt include any cooling (temporary) from volcanos. I dont think we want to count on volcanos to keep us less warm.
RockyRoad,
we often have to make conditional predictions because we cannot control certain things.
If your wife spends more than you make, you will go broke.
The math governing that is clear. What’s not clear is whether you can control the spending.
in most since we can do CONTROLLED experiments. Here we cannot,
The headpost is an advocacy piece, not a unbiased review. It wouldn’t much work to improve the quality of the article.
As Steve Mosher suggests, use Figure 1 from the author’s blog, which adjusts the starting point of the smoothed anomaly temp series to match the starting point of the 1990 prediction/projection. see http://clivebest.com/blog/wp-content/uploads/2011/06/normalised.png
It would also be nice to see the actual observed atmospheric CO2 concentrations vs. the scenarios used by the IPCC. Or even better, a comparison of the estimated CO2 emissions vs. the scenarios. In Hansen’s recent paper he notes that while emissions have been above the nominal AR4 projection, that the fraction of CO2 remaining in the atmosphere is below the estimates.
If someone wants to look at a serious comparison of AR4 projections vs observed temperatures, a good place is Lucia’s Blackboard, http://rankexploits.com/musings/2011/noaa-ncdc-april-warmer-than-march/
Thank you Dr Best. In the previous post on the latest UAH data, I mentioned a comparison with a predicted 0.3C per decade line, but you have done much better by comparing against actual IPCC predictions.
Steve Mosher is correct – to do a proper comparison you need to know a priori what the boundary conditions and source terms (aka “forcings”) are over the time period in question. This, of course, suggests that (1) climate is NOT a “boundary value problem” (since you never really know all the “boundary values” anyway), (2) climate models are mathematically ill-posed as they are currently formulated, and (3) when you do get a “solution” you can sometimes tune it get your hindcast right. And a good hindcast is all you need set policy decisions for the next 50 years,,,
steven mosher says:
June 9, 2011 at 5:37 pm
“Well jimbo, In Ar4 they ran models forward with a HIGH solar forcing. You could run them with both extremes.
For volcanos, its simple. The average over 100 years doesnt include any cooling (temporary) from volcanos. I dont think we want to count on volcanos to keep us less warm.”
All this says is that you are not willing to take into account phenomena in the real world that are far more easily predicted than the warming caused by manmade CO2, something that remains a total mystery – except in the minds of the Gaia modelers. All predictions must be about the real world. You have no plans for making predictions about the real world.
Steven Mosher says:
June 9, 2011 at 1:22 pm
“… The predictions are all CONDITIONAL. we dont control the experiment. this isnt like the lab and simple lab approaches miss the point and the complexity.”
This is an equivocation on the word “conditional.” All of us know that predictions are conditional. The complaint against you and other Gaia Modelers is that you do not have a clue what the conditions are. In other words, when you specify the conditions in your conditionals, they always turn out to be laughable. That is because you do no real world research that could reveal what the conditions are. You rely totally on your vision of one grand whole Gaia Model, a metaphysical fantasy if ever there was one.
I have this strange feeling of deja vu.
http://wattsupwiththat.com/2010/08/13/is-jim-hansens-global-temperature-skillful/
Steven Mosher says:
June 9, 2011 at 1:22 pm
“The other thing that the author should do is present the actual GHG forcing over the period in question. that is, the 1990 forecast is contingent upon assumed emissions. So, you really cannot simply compare the forecast to the observations. Most NOTABLY the forecast did not foresee or take into account any volcanic eruptions.
Simply: the forecast says : IF we see no volcanos after 1990, and IF the sun behaves as predicted, and IF the GHGs we putinto the atmosphere, THEN you will see temperatures go up like so.”
This is the most ill informed comment on prediction I have ever encountered. That is saying a lot. Mosher says that you cannot compare the forecast to the observations. The whole purpose of a forecast is to compare it to observations. Then in the second paragraph, Mosher treats the conditions in his conditional statement as excuses for the statement failing to agree with observations. That is a perverse interpretation of the statement. When you are using a conditional statement in a prediction, it is assumed that you have assigned a value to each condition that you fully expect to find realized in the world. Again, let me emphasize, to attempt to use the conditions as excuses for the falsehood of the prediction is perverse. It renders the concept of prediction totally empty of meaning.
To put this in plain terms, Mosher, no one cares if the temperatures go up given that everything behaves as you say it will; that is, no volcanoes after 1990, sun behaves as predicted, and GHGs etc. Mosher, what we care about is your claim that the world will be a certain way (no volcanoes after 1990, sun behaves as predicted, and GHGs etc.) and the temperature will go up. If you are willing to concede that you do not know about the conditions in your conditional, then who would care about the claim in the consequent that temperatures will go up?
Last I heard, Climate is a “chaotic” system. ….. and chaotic means unpredictable ….. so this whole exercise of trying to predict the future climate is rather futile.
Pompous Git says: “Mosh is of course correct that Hansen’s predictions were ceteris paribus; all scientific predictions are. That said, can you imagine the reaction of a bookmaker when asked to pay off on a bet when the horse lost, because,ceteris paribus, it should have won?”
Okay, PG, next time Ceteris Paribus runs at Pimlico, I’ll put a C note on him to finish in the money.
Steve Mosher,
I then presume that the SCOTUS decision to give Lisa Jackson and the EPA authority to regulate CO2 as a pollutant, justified primarily on IPCC studies, is conditional on there being no volcanic activity in the future. Can we consider that ruling now null and void? /sarc
Kidding aside, I see your point but as others have said here; your observation is more relevant in an academic as contrasted to a policy discussion. The latter is where the battle is being fought.
Tilo Reber says:
June 9, 2011 at 3:50 pm
Leif, I’m still waiting for an answer from you on another tread. What do you think about Mann using climate proxies upside down?
Must have missed it. Mann probably has his reasons [e.g. it fits better that way]. I have no particular opinion about his ‘work’. Other people have commented enough on it, I reckon. To comment on his work I would have to get access to all his data and do the analysis for myself. Then [and only then] would I be qualified to judge.
Pinatubo’s impact was fully dissappated by 1997 or so. There is no long-term change from Pinatubo, so this issue is a red herring for 2010 an 2011.
And the Sun, well, there is virtually no change in the solar irradiance making it to the Earth over the period, especially when one considers that the change is divided by 4 for the Earth being a sphere and we should reduce it to 70% because 30% of whatever change there is, is just reflected away. This what IPCC Far assumed.
There is virtually no change in the other big forcing group Aerosols, from 1990 to 2010. This was the expectation of Far as well.
CO2, however, is little lower today than the IPCC Far in the Business as Usual or Best scenario. The predicted CO2 level for 2000, for example, was 373 ppm while it ended up at 369 ppm. So not much difference really , a tiny amount lower than the BEST, business as usual estimate (they didn’t understand at the time the absorption by plants, oceans and soils would keep up with emissions). There is one other difference in that the forcing from CO2 was calculated at 6.3 ln(C/Co) versus today’s 5.35 ln(C/Co). But that is not an excuse, it just means they were wrong before.
So, the BEST projection is perfectly applicable, despite what others say, with no actual information apparently.
If you want more detailed information, go here.
http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_02.pdf
So, plug away Dr. Best. But the pro-AGW people do not like it when really good information like this is presented. So there will be cirticism to come.
Deanster says:
June 9, 2011 at 6:48 pm
“Last I heard, Climate is a “chaotic” system. ….. and chaotic means unpredictable ….. so this whole exercise of trying to predict the future climate is rather futile”
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Word. Chapter and verse.
There are some serious flaws in Clive’s graph:
1) If Clive is comparing temperature prediction with observation from 1990, then blue and green lines should be moved up to meet red lines AT 1990. This also corrects the HadCrut and UAH offsets (they use different reference temperatures).
2) Clive should not “Assume a linear extrapolating to May 2011:” as no IPCC modeling predicts linear temperature increase. It is very clear from 1990 graphs that temperature was predicted to accelerate mid century, meaning slower temperature increases now and lower gradient red lines.
3) Clive should not use 2011 data as it will have a cooling bias because the Northern Hemisphere summer temps are not yet in.
After these corrections are made, observed warming falls well within 1990 IPCC predictions – amazing for such a complex system.
Mat L says:
June 9, 2011 at 7:58 pm
There are some serious flaws in Clive’s graph:
…
“After these corrections are made, observed warming falls well within 1990 IPCC predictions – amazing for such a complex system.”
No they don’t. As faulty as that graph is, you’d have to really cherry pick your start date to get recent temperatures close to the IPCC scenarios – 1990 wouldn’t do it for you.
With all the natural sources of CO2 around, I haven’t seen any plans by warmists to begin plugging volcanoes.
Couple of recent quotes from Dr. Svalgaard:
If as Mosh points out, the two temperature curves were shifted to go through the 1900 point, the low IPCC prediction looks right on.
Mann probably has his reasons [e.g. it fits better that way]. I have no particular opinion about his ‘work’. Other people have commented enough on it, I reckon. To comment on his work I would have to get access to all his data and do the analysis for myself. Then [and only then] would I be qualified to judge.
Does anybody have any doubts now that Dr. Svalgaard is running with the hare and hunting with the hounds?
Both the wolves have eaten much and the sheep have not been touched!
After these corrections are made, observed warming falls well within 1990 IPCC predictions – amazing for such a complex system.
You’re kidding, right? Firstly it clearly doesn’t fall within predictions, but we’ll let that slide.
If I was asked to project the temperatures back in 1990 and I had predicted a linear increase based on the 1900 to 1990 increase, how much worse would that have been than the IPCC predictions?
That is the absolutely most naive prediction possible (no change in rate of increase) would have beaten the most sophisticated preditions of scientists. Now that is actually “amazing”!
The whitewash from Steven Mosher is CHEEP!
That was one of the biggest points from sceptics:
That, even IF there is some significant warming effect from CO2, it is easily overwhelmed by natural factors/variations, therefore irrelevant.
Sorry, CHEAP!