Models: some are good, some are not so good, some are useless.
To conclude, climate models can and have been verified against observations in a property that is most important for many users: the regional trends. This verification shows that many large-scale features of climate change are being simulated correctly, but smaller-scale observed trends are in the tails of the ensemble more often than predicted by chance fluctuations. The CMIP5 multi-model ensemble can therefore not be used as a probability forecast for future climate. We have to present the useful climate information in climate model ensembles in other ways until these problems have been resolved.
From http://www.realclimate.org/index.php/archives/2013/04/verification-of-regional-model-trends/
h/t to Steve Mosher
See also: http://www.gfdl.noaa.gov/cms-filesystem-action/user_files/tk/knutson_et_al_regional_trends_jan2013.pdf
Rbravery says:
April 15, 2013 at 12:41 pm
‘The actual quote from George Box was “essentially all models are wrong, some are useful”’
I started managing models back in the Seventies and I have always endorsed this view. But Alarmists insist that models can substitute for scientific theory and flatly contradict Box. Some models are useful if used wisely but they have no place in science except as analytic tools.
“The CMIP5 multi-model ensemble can therefore not be used as a probability forecast for future climate. We have to present the useful climate information in climate model ensembles in other ways until these problems have been resolved.(RealClimate).
Skeptic bloggers (and the Climategate whistleblower) give yourselves a pat on the back. The constant reality checks are having a strong positive effect (feedback, should I say?). This is huge from RealClimate, the blog that has given so much encouragement to the MSM, non-scientific supporters, academia – scientific and non scientific.
Eric Steig’s stepback: http://wattsupwiththat.com/2013/04/15/recent-climate-glacier-changes-in-antarctica-at-the-upper-bound-of-normal/
Withdrawals of papers that would have otherwise been published with fanfare: Lewandowski’s fraudulent psychiatric poppycock; Gergis et al’s paper retraction:
http://retractionwatch.wordpress.com/2012/06/11/paper-claiming-hottest-60-year-span-in-1000-years-put-on-hold-after-being-published-online/
A lot of rebranding is going on among AGW climate scientists who held sway for years under the cloak of dank intellectual darkness. Amazing the developments possible when the light and fresh air are let in. Interesting, that there will be the few, no matter what transpires, who will not come in from the cold so to speak. Now here’s real a subject for study by the discipline that Lewandowski so badly represents.
Translation, Hansen is quitting, the new boss will never allow this nonsense to continue,I am so screwed. G.
lsvalgaard,
Keep ’em honest Leif. We can’t fight bad science with pseudo-science.
It is not necessary to posit another theory to falsify a failed one.
Perhaps because the cloak and dagger stuff is far more entertaining than anything so boring as actually understanding the issue?
Realclimate and IPCC have long said that climate models are not reliable when it comes to local (sub-regional) scales. The post at realclimate cited here is discussing whether or not this has improved with the latest CMIP5 models.
This is not an “admission” of anything, this is an update on a well-known issue with climate models, with the message that the issue has not been overcome yet.
You have to be ignorant of climate modelling to spin it any other way. Below are cited realclimate articles over the past few years, as well as the IPCC, pointing out the issue that some people upthread appear to believe is a new disclosure.
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TAR 2001 – “The limitations of AOGCM regional information are, however, well known. By definition, coupled AOGCMs cannot provide direct information at scales smaller than their resolution (order of several hundred kilometres), neither can AOGCMs capture the detailed effects of forcings acting at sub-grid scales (unless parametrized).”
Realclimate 2005 – “It’s important to note what these models are not good for. They aren’t any good for your local weather, or the temperature of the water at the nearest beach or for the wind in downtown Manhattan, because these are small scale features, affected by very local conditions. However, if you go up to the regional scale and beyond (i.e. Western Europe as a whole, the continental US) you start to expect better correlations.”
Realclimate 2007 – “Yet, whereas the global climate models (GCMs) tend to describe the global climate statistics reasonably well, they do not provide a representative description of the local climate.”
Realclimate 2010 – “In fact, global atmospheric and climate models are better at describing the large picture than more regional and local characteristics. There is a limit to what they are able to describe in terms of local regional details..”
Realclimate 2011 – “We have already discussed why climate models are not well suited for providing detailed information about local climate on RC (here and here). It is important to keep in mind that models are only approximate representation of the real world, and that they are only meant to capture the essence of our climate – i.e. the larger picture. There will always be a limit to the degree of detail for which the models fail to produce reliable and useful information, and the interesting question is where this limit is.”
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That’s a small sample, representative of something widely known and often talked about at SkS, realclimate, by IPCC and any of the catastrophising alarmistic denizens we love to hate. Nothing new has been disclosed here, there has been no “admission.” Only an update. If you want to propagandise the realclimate post, try this:
“Climate models still not good enough at sub-regional scales. They can’t predict the most important aspect – what will happen where you live!”
That won’t help the genuinely curious learn anything, of course, but it makes for a sound byte that has the benefit of being true.
My wife, a second grade school teacher asks:
Are they saying that on a 100-500 year time scale the models are good?
Or will the predicted warming be validated when the sun expands and engulfs the earth?
I just want to make sure that I teach it correctly.
@Barry:
Ahhh, but therein lies the fallacy of the climate models.
It is claimed that they are based on well understood physics.
The fact the individual parts fail indicates they don’t really understand what is going on. However, the assumptions used in various parameters are sufficiently tweaked that the overall result matches what they are looking for. This is why the climate models work great, until they don’t.
All models are wrong. Some are useful.
Why do you think the aerospace companies spend so much money on scaled prototypes to verify the models [of physics that is understood far better than climate] used to predict flight behaviour?
barry says:
April 16, 2013 at 3:06 am
I’m certain that Barry will jump at the opportunity to demonstrate how the models accurately forecast the 5 consecutive bitter winters in Europe/Asia to support his point.
And while you’re at it Barry, please educate us as to how the models are good enough at forecasting supra-regional scales, yet “Climate models still not good enough at sub-regional scales”.
Who appoints Hansen’s successor — O, on Holdren’s
oops:
Who appoints Hansen’s successor — O, on Holdren’s recommendation?
Barry,
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch11s11-references.html
Could you pass the memo on to IPCC? It is nice to know that I can throw these regional assessment papers away now. I can link a few hundred more regional projections/scenario papers, including from realclimate, but I don’t wanna spam the truth.
Boo, K.-O., W.-T. Kwon, and H.-J. Baek, 2006: Change of extreme events of temperature and precipitation over Korea using regional projection of future climate change. Geophys. Res. Lett., 33(1), L01701, doi:10.1029/2005GL023378.
Tebaldi, C., L.O. Mearns, D. Nychka, and R. Smith, 2004a: Regional probabilities of precipitation change: A Bayesian analysis of multi-model simulations. Geophys. Res. Lett., 31, L24213, doi:10.1029/2004GL021276.
Tebaldi, C., R. Smith, D. Nychka, and L.O. Mearns, 2004b: Quantifying uncertainty in projections of regional climate change: A Bayesian Approach. J. Clim., 18(10), 1524–1540.
Unnikrishnan, A.S., et al., 2006: Sea level changes along the Indian coast: Observations and projections. Curr. Sci. India, 90, 362–368.
Whetton, P.H., and R. Suppiah, 2003: Climate change projections and drought. In: Science for Drought. Proceedings of the National Drought Forum, Carlton Crest Hotel, Brisbane [Stone, R., and I. Partridge (eds.)]. Queensland Department of Primary Industries, Brisbane, Qld., pp. 130–136.
Whetton, P.H., A.B. Mullan, and A.B. Pittock, 1996: Climate-change scenarios for Australia and New Zealand. In: Greenhouse: Coping with Climate Change [Bouma, W.J., G.I. Pearman, and M.R. Manning (eds.)]. CSIRO, Collingwood, Vic., pp. 145–168.
Whetton, P.H., et al., 2001: Developing scenarios of climate change for Southeastern Australia: An example using regional climate model output. Clim. Res., 16(3), 181–201.
Whetton, P. H., et al. 2002. Climate change in Victoria : high resolution regional assessment of climate change impacts. Undertaken for the Victorian Department of Natural Resources and Environment. Dept. of Natural Resources and Environment, East Melbourne, VIC, 44 pp., http://www.greenhouse.vic.gov.au/climatechange.pdf
Whetton, P.H., et al., 2005: Australian Climate Change Projections for Impact Assessment and Policy Application: A Review. CSIRO Marine and Atmospheric Research Paper 001, CSIRO Marine and Atmospheric Research, Aspendale, Vic., 34 pp.
Widmann, M., C.S. Bretherton, and E.P. Salathé Jr., 2003: Statistical precipitation downscaling over the Northwestern United States using numerically simulated precipitation as a predictor. J. Clim., 16, 799–816.
Wilby, R.L., C.W. Dawson, and E.M. Barrow, 2002: SDSM – A decision support tool for the assessment of regional climate change impacts. Environ. Model. Software, 17, 147–159.
Climate “Models: some are good, some are not so good, some are useless — and they swap places at random.
Various:
Newton’s model of the universe fails at various levels (Relativity and quantum physics fill some of the gaps), but we can still use it to land a rocket on the moon. The point is not perfection but utility. You make this point in your post.
Any parametrization is done to simulate average conditions. Nobody claimed the physics was perfectly understood. No one makes this claim for any complex modelling.
Why would I do that, when it is antithetical to the conclusions of the realclimate article and the various studies it is based on?
I’m not qualified to do that. I’d be reaching far beyond my ken. But anyone here could read about it if they so chose.
Regional models are different from GCMs. I expect much of the work you are citing is about the development of regional models. I doubt many of them would be claiming precision. I doubt you’ve read any of these papers you’re going to throw away.
Despite the lack of perfection, people keep plugging away at modelling various scales of the Earth’s climate system. Others snipe about it, hoover up a few links to deposit in a forum, and don’t care about the subject further than is necessary to rubbish it.
I am not interested in or even capable of giving an in-depth explanation of the hows and whys of climate models. I just know enough to be able to say that many of the comments above are ignorant (or worse).
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Seems to me that people here believe the skill of climate models is continually oversold. Now that realclimate have posted an article pointing out where climate models fail, this requires some mental acrobatics to make the narrative work. Thus Sam the First “suspects their motives,” for example. And the article above is headlined that realclimate have ‘admitted’ something.
Rather than take the article at face value, a spin is invented. It fits the narrative here, but is divorced from reality. There is no “admission,” this is not a new development. The basic point is “no major improvement yet.”
That’s my point. Anyone wants to learn more about climate models can find plenty of information on the net.
barry:
re your nonsense about climate models in your post at April 16, 2013 at 4:03 pm.
Please read my post at April 18, 2013 at 4:28 am in the thread at
http://wattsupwiththat.com/2013/04/17/temperature-models-vs-temperature-reality-in-the-lower-troposphere/
I think you need to know.
Richard