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AbruptSLR

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Re: Validation of GCM Models
« Reply #50 on: March 20, 2017, 01:16:39 AM »
At the moment, I'm not so interested in notions of verification, "the old guard" & etc but whether the quote posted by AbruptSLR has any credence...

"Scientists are now saying it might already be too late to avoid a temperature rise of up to 7.36 degrees Celsius (13.25 degrees Fahrenheit) above pre-industrial levels by 2100.
That's way above the upper limit of 4.8 degrees Celsius (8.6 degrees Fahrenheit) predicted by the Intergovernmental Panel on Climate Change (IPCC) in 2014, and to make matters worse, a new study suggests that we're underestimating just how sensitive Earth is to greenhouse gases.



Geoff,

So that you can decide for your, I selected the following 28 references [not including either von der Heydt et. al. 2016 nor Friedrich et al (2016)] that either directly, or indirectly, indicate that climate sensitivity is most likely significantly higher than the range summarized by AR5:

1. The linked reference analyses the CMIP3&5 results to conclude the ECS is likely 3.9C +/- 0.45C:

Chengxing Zhai, Jonathan H. Jiang & Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911


http://onlinelibrary.wiley.com/doi/10.1002/2015GL065911/full

2. The linked reference provides findings from CMIP5 of the continued poleward expansion of the Hadley Cell with continued global warming; which in-turn supports the idea that ECS is greater than 3C:

Lijun Tao, Yongyun Hu & Jiping Liu (May 2016), "Anthropogenic forcing on the Hadley circulation in CMIP5 simulations", Climate Dynamics, Volume 46, Issue 9, pp 3337-3350 DOI: 10.1007/s00382-015-2772-1

http://rd.springer.com/article/10.1007%2Fs00382-015-2772-1

3. The linked reference presents new paleo evidence about the Eocene.  While the authors emphasize that their findings support the IPCC interpretation for climate sensitivity, when looking at the attached Fig 4 panel f, it appears to me that this is only the case if one averages ECS over the entire Eocene; while if one focuses on the Early Eocene Climate Optimum (EECO) which CO₂ levels were higher than in current modern times, it appear that ECS was higher (around 4C) than the IPCC AR5 assumes (considering that we are increasing CO2 concentrations faster now that during the EECO this gives me concern rather than reassurance).

Eleni Anagnostou, Eleanor H. John, Kirsty M. Edgar, Gavin L. Foster, Andy Ridgwell, Gordon N. Inglis, Richard D. Pancost, Daniel J. Lunt & Paul N. Pearson (2016), "Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate", Nature, doi:10.1038/nature17423


http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17423.html

4. Tan et al (2016) indicates that ECS may well be between 5.0 and 5.3C.

Ivy Tan, Trude Storelvmo & Mark D. Zelinka (08 Apr 2016), "Observational constraints on mixed-phase clouds imply higher climate sensitivity", Science, Vol. 352, Issue 6282, pp. 224-227, DOI: 10.1126/science.aad5300


http://science.sciencemag.org/content/352/6282/224

5. According to the IPCC AR5 report: "The transient climate response is likely in the range of 1.0°C to 2.5°C (high confidence) and extremely unlikely greater than 3°C"; however, the linked reference uses only observed data to indicate that TCR is 2.0 +/- 0.8C.  Thus AR5 has once again erred on the side of least drama.


T. Storelvmo, T. Leirvik, U. Lohmann, P. C. B. Phillips & M. Wild (2016), "Disentangling greenhouse warming and aerosol cooling to reveal Earth’s climate sensitivity", Nature Geoscience, doi:10.1038/ngeo2670


http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2670.html

6. The linked reference reassesses ECS from CMIP3 &5 and find an ensemble-mean of 3.9C, and I note that CMIP3&5 likely err on the side of least drama as they ignore several important non-linear slow feedbacks that could be accelerated by global warming:

Chengxing Zhai, Jonathan H. Jiang, Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065911/full

7. The linked reference could not make it more clear that paleo-evidence from inter-glacial periods indicates that ECS is meaningfully higher than 3C and that climate models are commonly under predicting the magnitude of coming climate change.

Dana L. Royer (2016), "Climate Sensitivity in the Geologic Past", Annual Review of Earth and Planetary Sciences, Vol. 44


http://www.annualreviews.org/doi/abs/10.1146/annurev-earth-100815-024150?src=recsys

8. Thompson indicates that ECS has a 95%CL range of from 3C to 6.3C, with a best estimate of 4C, and Sherwood (2014) has a higher value still:

Climate sensitivity by Roy Thompson published by Earth and Environmental Science Transactions of the Royal Society of Edinburgh, DOI: 10.1017/S1755691015000213

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10061758&fileId=S1755691015000213


9. Tian (2015) indicates that the double-ITCZ bias constrains ECS to its high end (around 4.0C):

Tian, B. (2015), "Spread of model climate sensitivity linked to double-Intertropical Convergence Zone bias", Geophys. Res. Lett., 42, doi:10.1002/2015GL064119.


http://onlinelibrary.wiley.com/doi/10.1002/2015GL064119/abstract

10. Sherwood et al (2014), which found that ECS cannot be less than 3C, and is likely currently in the 4.1C range.  Also, everyone should remember that the effective ECS is not a constant, and models project that following a BAU pathway will result in the effective ECS increasing this century:


Sherwood, S.C., Bony, S. and Dufresne, J.-L., (2014) "Spread in model climate sensitivity traced to atmospheric convective mixing", Nature; Volume: 505, pp 37–42, doi:10.1038/nature12829

http://www.nature.com/nature/journal/v505/n7481/full/nature12829.html

11. The linked reference studies numerous climate models and finds that: "… those that simulate the present-day climate best even point to a best estimate of ECS in the range of 3–4.5°C."
Reto Knutti, Maria A. A. Rugenstein (2015), "Feedbacks, climate sensitivity and the limits of linear models", Philosophical Transactions of the Royal Society A, DOI: 10.1098/rsta.2015.0146

http://rsta.royalsocietypublishing.org/content/373/2054/20150146

12.  The linked reference indicates that the cloud feedback from tropical land is robustly positive.  As AR5 did not know whether this contribution to climate sensitivity was positive or negative, this clearly indicates that AR5 errs on the side of least drama with regard to both TCR & ECS:

Youichi Kamae, Tomoo Ogura, Masahiro Watanabe, Shang-Ping Xie and Hiroaki Ueda (8 March 2016), "Robust cloud feedback over tropical land in a warming climate", Atmospheres, DOI: 10.1002/2015JD024525

http://onlinelibrary.wiley.com/doi/10.1002/2015JD024525/abstract

13.  Graeme L. Stephens, Brian H. Kahn and Mark Richardson (5 May, 2016), "The Super Greenhouse effect in a changing climate", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0234.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0234.1

14. The linked reference assumes different degrees of nonlinearity for climate feedback mechanisms and concludes that such nonlinearity for positive feedback represents a Black Swan risk that linear climate models cannot recognize:

Jonah Bloch-Johnson, Raymond T. Pierrehumbert & Dorian S. Abbot (24 June 2015), "Feedback temperature dependence determines the risk of high warming", Geophysical Research Letters, DOI: 10.1002/2015GL064240

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064240/full


15.  While the linked (open access) reference has many appropriate qualifying statements and disclaimers, it notes that the AR5 paleo estimates of ECS were linear approximations that change when non-linear issues are considered.  In particular the find for the specific ECS, S[CO2,LI], during the Pleistocence (ie the most recent 2 million years) that:
"During Pleistocene intermediate glaciated climates and interglacial periods, S[CO2,LI] is on average ~ 45 % larger than during Pleistocene full glacial conditions."

Therefore, researchers such as James Hansen who relied on paleo findings that during recent full glacial periods ECS was about 3.0C, did not know that during interglacial periods this value would be 45% larger, or 4.35C.

Köhler, P., de Boer, B., von der Heydt, A. S., Stap, L. B., and van de Wal, R. S. W. (2015), "On the state dependency of the equilibrium climate sensitivity during the last 5 million years", Clim. Past, 11, 1801-1823, doi:10.5194/cp-11-1801-2015.


http://www.clim-past.net/11/1801/2015/cp-11-1801-2015.html
http://www.clim-past.net/11/1801/2015/cp-11-1801-2015.pdf

16.  The linked reference implies that climate sensitivity (ESS) could be much higher than previously assumed:

Jagniecki,Elliot A. et al. (2015), "Eocene atmospheric CO2from the nahcolite proxy", Geology, http://dx.doi.org/10.1130/G36886.1


http://geology.gsapubs.org/content/early/2015/10/23/G36886.1

17.  The linked open access reference identifies three constraints on low cloud formation that suggest that cloud feedback is more positive than previously thought.  If verified this would mean that both TCR and ECS (and ESS) are larger than previously thought:

Stephen A. Klein and Alex Hall (26 October 2015), "Emergent Constraints for Cloud Feedbacks", Climate Feedbacks (M Zelinka, Section Editor), Current Climate Change Reports, pp 1-12, DOI 10.1007/s40641-015-0027-1

http://link.springer.com/article/10.1007%2Fs40641-015-0027-1

18.  The linked article indicates that values of TCR based on observed climate change are likely underestimated:

J. M. Gregory, T. Andrews and P. Good (5 October 2015), "The inconstancy of the transient climate response parameter under increasing CO₂", Philosophical Transactions of the Royal Society A, DOI: 10.1098/rsta.2014.0417


http://rsta.royalsocietypublishing.org/content/373/2054/20140417

19.  The linked reference indicates that most current climate models underestimate climate sensitivity:

J. T. Fasullo, B. M. Sanderson & K. E. Trenberth (2015), "Recent Progress in Constraining Climate Sensitivity With Model Ensembles", Current Climate Change Reports, Volume 1, Issue 4, pp 268-275, DOI 10.1007/s40641-015-0021-7

http://link.springer.com/article/10.1007/s40641-015-0021-7?wt_mc=email.event.1.SEM.ArticleAuthorOnlineFirst

20.  The linked reference indicates that studies that assuming linearity of climate sensitivity likely underestimate the risk of high warming.

Jonah Bloch-Johnson, Raymond T. Pierrehumbert and Dorian S. Abbot (June 2015), "Feedback temperature dependence determines the risk of high warming", Geophysical Research Letters, DOI: 10.1002/2015GL064240

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064240/abstract

21. The linked reference indicates that new research (from PlioMIP2) demonstrates that the climate sensitivity for the Pliocene was higher than previously believed (from PlioMIP1):

Kamae, Y., Yoshida, K., and Ueda, H.: Sensitivity of Pliocene climate simulations in MRI-CGCM2.3 to respective boundary conditions, Clim. Past, 12, 1619-1634, doi:10.5194/cp-12-1619-2016, 2016.

http://www.clim-past.net/12/1619/2016/

http://www.clim-past.net/12/1619/2016/cp-12-1619-2016.pdf


22. The linked reference indicates that corrected recent observations indicate that the most likely value of ECS may be as high as 4.6C (see attached plot of the time dependent curve):

Kyle C. Armour  (27 June 2016), "Projection and prediction: Climate sensitivity on the rise", Nature Climate Change, doi:10.1038/nclimate3079

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3079.html

23. The linked reference indicates that the climate responses (climate sensitivities) projected by advanced climate models generally match observations when apple to apple comparisons are made.  This is a useful finding as advanced climate models generally indicate that climate sensitivity values are towards the high end of the IPCC climate sensitivity range:

Mark Richardson, Kevin Cowtan, Ed Hawkins & Martin B. Stolpe (2016), "Reconciled climate response estimates from climate models and the energy budget of Earth", Nature Climate Change, doi:10.1038/nclimate3066

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3066.html

24. The linked reference discusses paleodata to indicate that climate sensitivity increased from 3.3 - 5.6 (mean of 4.45k) at the beginning of the PETM up to 3.7 - 6.5 K (mean of 5.1K) near the peak of the PETM; and that if we burn only the easily accessible carbon reserves then GMST could increase by about 10C.  I note these climate sensitivity values are much higher than those inherent in the CMIP5 projections:

Gary Shaffer, Matthew Huber, Roberto Rondanelli & Jens Olaf Pepke Pedersen (23 June 2016), "Deep-time evidence for climate sensitivity increase with warming", Geophysical Research Letters, DOI: 10.1002/2016GL069243

http://onlinelibrary.wiley.com/doi/10.1002/2016GL069243/full


25. The linked Reuters article notes that NASA reported that a new satellite-based method have located 39 unreported sources of anthropogenic emissions that, when accounted for, increase our previously estimated amount of sulfur dioxide by about 12 percent of all such anthropogenic emissions from 2005 to 2014.  This indicates that the CMIP5 projections also underestimated the impact of this negative forcing source; which raises the prospect that climate sensitivity (ECS) is likely higher than the CMIP5 models indicate, and the linked Zhai et al (2015) reference analyses of the CMIP3&5 results conclude that the ECS is likely 3.9C +/- 0.45C:

Chengxing Zhai, Jonathan H. Jiang & Hui Su (2015), "Long-term cloud change imprinted in seasonal cloud variation: More evidence of high climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2015GL065911

http://in.reuters.com/article/us-nasa-pollution-idINKCN0YO1PW

26. The linked reference uses an information-theoretic weighting of climate models by how well they reproduce the satellite measured deseasonlized covariance of shortwave cloud reflection, indicates a most likely value of ECS of 4.0C; which indicates that AR5 errs on the side of least drama:

Florent Brient & Tapio Schneider (2016), "Constraints on climate sensitivity from space-based measurements of low-cloud reflection", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0897.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0897.1


27. The linked article indicates that the contribution of sea-ice loss to Arctic Amplification is regulated by the PDO and that in positive PDO phases (like we are in now) there should be less Arctic Amplification.  Thus the fact that we are currently experiencing high Arctic Amplification during a period of highly positive PDO values gives cause for concern that climate sensitivity may be higher than considered by AR5:

James A. Screen & Jennifer A. Francis (2016), "Contribution of sea-ice loss to Arctic amplification is regulated by Pacific Ocean decadal variability", Nature Climate Change, DOI: 10.1038/nclimate3011


http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3011.html


28. The linked reference uses an information-theoretic weighting of climate models by how well they reproduce the satellite measured deseasonlized covariance of shortwave cloud reflection, indicates a most likely value of ECS of 4.0C.  As this satellite data is certainly biased by the recent acceleration of natural aerosol emissions associated with the increasing atmospheric CO2 concentration, the actually ECS is likely higher than 4.0C, as will become apparent if climate change reduces future plant activity.  Unfortunately, the envisioned upgrades to the Paris Pact do not have any contingency for addressing such high values (4 to 4.5C) of ECS (including accelerting NET):

Florent Brient & Tapio Schneider (2016), "Constraints on climate sensitivity from space-based measurements of low-cloud reflection", Journal of Climate, DOI: http://dx.doi.org/10.1175/JCLI-D-15-0897.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0897.1

Best regards,
ASLR,

Edit: And for those who do not like to read, I provide the two attached images of high equilibrium climate sensitivity, with the first based on paleo data, and the second based on modern observations.
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GeoffBeacon

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Re: Validation of GCM Models
« Reply #51 on: March 20, 2017, 01:31:33 AM »
Crandles

A different commentary on the paper
https://julesandjames.blogspot.co.uk/2016/11/apocalpyse-now.html


The critical comments after the article you cite do weaken the effect of Friedrich et. al.'s Nonlinear climate sensitivity and its implications for future greenhouse warming but I'm still worried about "missing feedbacks".

By how much are the CMIP5 models too optimistic because of "missing feedbacks"? Has anyone any good guesses?

I suppose we all worry about painting a picture of climate change that is so dark it becomes unbelievable to the public (Particularly if it is too pessimistic in the short term). On the other hand there is the worry about the delayers argument that climate change isn't so bad that we need to worry much about it.

The remaining carbon budget is a topics I can use in making representations to politicians, government bodies & etc. The status of the "missing feedbacks" has an important impact on this.

(EDIT: ALSR. Thanks for the homework. I was typing this at the time. It looks as if I will need time to digest it)

(EDIT2: Some students I know are organising a climate lecture in York, UK. They already have a prominent denier and are looking for a climate scientist to counter him. I suggested Kevin Anderson but I don't think he's replied yet. Any other suggestions? I'll see if I can get help with the homework!)
« Last Edit: March 20, 2017, 01:42:39 AM by GeoffBeacon »
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DrTskoul

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Re: Validation of GCM Models
« Reply #52 on: March 20, 2017, 02:50:05 AM »

(EDIT2: Some students I know are organising a climate lecture in York, UK. They already have a prominent denier and are looking for a climate scientist to counter him. I suggested Kevin Anderson but I don't think he's replied yet. Any other suggestions? I'll see if I can get help with the homework!)

What is the point of debating a Gish galloper?? It is almost futile unless the climate scientist is able for a Gish gallop of his own. Countering one by one the points of a Gish gallop is a waste of time....
“You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird... So let's look at the bird and see what it's doing -- that's what counts.”
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jai mitchell

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Re: Validation of GCM Models
« Reply #53 on: March 20, 2017, 05:15:50 AM »

By how much are the CMIP5 models too optimistic because of "missing feedbacks"? Has anyone any good guesses?


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Pmt111500

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Re: Validation of GCM Models
« Reply #54 on: March 20, 2017, 05:22:26 AM »

(EDIT2: Some students I know are organising a climate lecture in York, UK. They already have a prominent denier and are looking for a climate scientist to counter him. I suggested Kevin Anderson but I don't think he's replied yet. Any other suggestions? I'll see if I can get help with the homework!)

What is the point of debating a Gish galloper?? It is almost futile unless the climate scientist is able for a Gish gallop of his own. Countering one by one the points of a Gish gallop is a waste of time....
Basically it could become a general lecture on AGW with regular disturbances of the stupidest student. This should end up (again) by the stupidest student thinking his views are reinforced, and the listeners (hopefully) thinking this guy should be expelled. The denier will prepare with talking point memo that might have one or two hard to explain points of discussion and the scientist requiring more time than him which the inane idiot will take as break of debate rules. The rest of the memo contains shouts that interrupt explanations of inconvenient truths by the scientist thus disrupting the potential for learning for people who aren't already convinced that renewable(well ok, also nuclear, with way less highly active waste) energy is the only viable option for energy generation and transport if we as a species do not want sea levels of at least 9 meters higher and "who anyway cares what happens in 200 years, and is it 200 or 400 maybe and J.Hansen is a retired loonie."
Oh, the times when talking of car and especially driver performances at the latest wc rally have taken over the discussion at the local bar that only infrequents engineers. I for one was glad to hear about the start of electric drive-train manufacturing start at the local car builder. Oh yeah. Everybody though admits you cannot get as far in a day by electric cars than by internal combustion engine and leasing a car for the summer vacation trip is beyond them. Nice.

This is starting to become a rant so I stop. Thank you for listening and remember the disadvantages of electric rail/cars and the intermittency of wind/solar.
« Last Edit: March 20, 2017, 05:43:51 AM by Pmt111500 »
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Pmt111500

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Re: Validation of GCM Models
« Reply #55 on: March 20, 2017, 05:33:35 AM »
Oh, this was the 'validation of gcms'-thread. Sorry for the last one. Validation of gcms proceeds in many steps. Firstly, you gotta get the normal ghg-effect equations so correct that you get the surface temperature to rise from the non-ghg temperature of -17,5 c (or was it -18,5°C?) to rise to the observed preindustrial temperatures. There was a lengthy explanation of further validation steps somewhere, but not on computer so not going to find and summa4rize it right away.
« Last Edit: March 20, 2017, 05:55:45 AM by Pmt111500 »
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Jim Hunt

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Re: Validation of GCM Models
« Reply #56 on: March 20, 2017, 09:48:08 AM »
No wonder I tend to ignore you when you say anything other than pure direct data.  You are asking me to waste my time before giving me a reason to waste it.

Don't you understand economics at all???????


Jim - I've recently spent many happy hours in the company of the deplorable denizens:

http://GreatWhiteCon.info/2017/03/that-deaf-dumb-and-blind-kid-sure-plays-a-mean-climateball/

Your tactics are identical to theirs.

Please stop being so patronising. Stop the ad homs. State your case, if you have one.
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Red

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Re: Validation of GCM Models
« Reply #57 on: March 20, 2017, 11:33:49 AM »
No wonder I tend to ignore you when you say anything other than pure direct data.  You are asking me to waste my time before giving me a reason to waste it.

Don't you understand economics at all???????


Jim - I've recently spent many happy hours in the company of the deplorable denizens:

http://GreatWhiteCon.info/2017/03/that-deaf-dumb-and-blind-kid-sure-plays-a-mean-climateball/

Your tactics are identical to theirs.

Please stop being so patronising. Stop the ad homs. State your case, if you have one.

A layman's view.
Mr. Hunt after discovering your blog over the last few weeks I have to say your a dog for punishment. However I think we need more like you to chew up and spit out the crap of the denial industry. I love to read the past posts and the comment threads in particular. As with the ASIF the threads are always enlightening and great resources. I think I understand Mr. Williams point of view a little and think it may have more to do with predictions,(I could be way off base). Being very interested in CC for three decades or so and having most of my info coming from a list of authors to long to list it was always probably a decade old by the time it landed on the bookstore shelves. Then the IPCC reports started hitting the news in a big way at the turn of the century. Things like the Larsen B is fine for decades, gone two years later. The west Antarctic good for many decades to come and the east, millennium, both now looking unstable this century. 2c maybe this century now 4c-7c, 2c before 2050. SLR +/- 1 metre now maybe 4-5 metres. I see a lot of discussion about how they aren't really set up to do predictions. So why stick your neck out like that? I know at the regional level politicians want relevant info for planning, but if the bureaucrats at the top are dumbing down the science to render it void for that purpose it leaves the layperson thinking the science is wrong. When those of us paying attention see the next century away stuff going off every where now! I work in construction and the folks 40 to 60 years old see the changes and know something is changing for the worse. Those that look, think as I did, the models got it wrong. It's only after doing a lot of research on my own that I started to realize it was the politics that was causing the problem. I believe it to be unrealistic to think that a model that isn't robust enough to take in all the inputs,(if that's even possible), could be accurate enough for those sorts of demands. As I understand it, to have a processor big enough to run such a model, if it could even be constructed, would use most of our energy supply to run. Well we have that model now it just doesn't do print outs. We are the living print out. Point is I don't think so much that the models are wrong as incomplete. The ECS would seem to be pointing that out to our dismay. It may well be we need AI to run such a model and may even require it to build it. AI is in the foreseeable future, lets hope the ECS doesn't out run our ability to save ourselves as well as most of the flora and fauna on the planet.     

DrTskoul

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Re: Validation of GCM Models
« Reply #58 on: March 20, 2017, 12:12:20 PM »
You don't need AI to run any of those models. And a model is  by construct incomplete. It tries to uncover the major physics and processes and it can not account for all time scales... from the chemistry of the oceans to tectonics. The more complex the model the more difficult to parse the output and make correlations that are valuable and traces back to specific physical processes. We have the real life model as you said. We have managed to only make empirical connections e.g. with El Nino we have these expected weather patterns, which some times materialize and others not.

Without the reductive nature of models we would learn nothing about the underlying physical processes.
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Jim Williams

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Re: Validation of GCM Models
« Reply #59 on: March 20, 2017, 12:50:26 PM »
If I am right, then nothing I/we do now makes a bit of difference.  The war was lost 200 years ago.

Great, so the only reason you post here, is to vent your frustrations. That's not the intended use of the ASIF, so any more denier-mirror Dunning-Kruger BS or disrespect shown to people who engage with you and take the time to refer you to stuff (the 'herd' of persecutors), and I'm putting you under moderation.

Your actions and what you say don't match. A true doomer wouldn't be wasting time on some obscure forum. He'd be listening to Bach and reading Tolstoy. Go punch a bag or something.

Normally I'd PM this, but I've let this go on for long enough.
I come here to watch the ice melt.

Neven

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Re: Validation of GCM Models
« Reply #60 on: March 20, 2017, 01:05:36 PM »
Now, that is the intended use of the ASIF.
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TerryM

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Re: Validation of GCM Models
« Reply #61 on: March 20, 2017, 05:56:09 PM »
With all of the mentioning of works that point to an under evaluation of climate highs, are there any, other than the deniers, that feel that science is overstating the dangers going forward?


Thanks
Terry

Ninebelowzero

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Re: Validation of GCM Models
« Reply #62 on: March 20, 2017, 06:42:21 PM »
With all of the mentioning of works that point to an under evaluation of climate highs, are there any, other than the deniers, that feel that science is overstating the dangers going forward?


Thanks
Terry


In a humanocentric world when all the ice has gone will scientists be able to predict what the climate will be like not just in the Arctic but in highly populated regions elsewhere?.

Many fish species are already on the move. How many other species will become extinct?

AbruptSLR

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Re: Validation of GCM Models
« Reply #63 on: March 20, 2017, 09:26:09 PM »
Perhaps this thread should be renamed: "If Decision Makers Don't Care to Take Effective Action, Why Should Scientists Work to Refine Their Imperfect GCM Models?"
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gerontocrat

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Re: Validation of GCM Models
« Reply #64 on: March 20, 2017, 10:28:01 PM »
Perhaps this thread should be renamed: "If Decision Makers Don't Care to Take Effective Action, Why Should Scientists Work to Refine Their Imperfect GCM Models?"

To bear witness. To leave a record.

AbruptSLR

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Re: Validation of GCM Models
« Reply #65 on: March 20, 2017, 11:30:12 PM »
Perhaps this thread should be renamed: "If Decision Makers Don't Care to Take Effective Action, Why Should Scientists Work to Refine Their Imperfect GCM Models?"

To bear witness. To leave a record.

As Neven pointed out, the ASIF is doing a good job of documenting the decline of the Arctic Sea Ice for the good of posterity.
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Re: Validation of GCM Models
« Reply #66 on: March 21, 2017, 09:53:28 AM »
Neven - You haven't moderated Jim W's apology have you?

Jim W. - At the risk of repeating myself, you've flung the vaguest of insults loudly in my direction. Please state your case or apologise.

Alternatively, in some words I picked up off ex Prof. Judy’s cutting room floor:

https://andthentheresphysics.wordpress.com/2017/02/05/expose-david-rose-does-not-understand-baselines/#comment-91207

Thank you for your attention.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

gerontocrat

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Re: Validation of GCM Models
« Reply #67 on: March 21, 2017, 11:25:07 AM »
Perhaps this thread should be renamed: "If Decision Makers Don't Care to Take Effective Action, Why Should Scientists Work to Refine Their Imperfect GCM Models?"

To bear witness. To leave a record.

As Neven pointed out, the ASIF is doing a good job of documenting the decline of the Arctic Sea Ice for the good of posterity.

Yes, and the need has never been greater with the prospect of climate science being cut off at the knees in the USA. But I am veering in the direction of policy, actions, solutions and can feel a moderator hovering over the delete button. So je suis fini.


Jim Williams

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Re: Validation of GCM Models
« Reply #68 on: March 21, 2017, 12:29:23 PM »
Neven - You haven't moderated Jim W's apology have you?

Jim W. - At the risk of repeating myself, you've flung the vaguest of insults loudly in my direction. Please state your case or apologise.

Alternatively, in some words I picked up off ex Prof. Judy’s cutting room floor:

https://andthentheresphysics.wordpress.com/2017/02/05/expose-david-rose-does-not-understand-baselines/#comment-91207

Thank you for your attention.
I do not remember saying anything to you, and I do not apologise for stating facts -- the GCM are pure crap.

Jim Hunt

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Re: Validation of GCM Models
« Reply #69 on: March 21, 2017, 03:28:34 PM »
I do not remember saying anything to you.


You have a remarkably short memory Jim. Allow me to refresh it for you:

Don't you understand English at all?
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

AbruptSLR

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Re: Validation of GCM Models
« Reply #70 on: March 21, 2017, 03:42:07 PM »
The link to the following April 2016 EGU General Assembly press conference 8 video clip roughly focused on the implications of the Paris Pact:

http://client.cntv.at/egu2016/press-conference-8

While the entire video is worth watching I provide the first attached image/screen shot showing DeConto & Pollard's (2016 EGU) projections of Antarctic contributions to changes in global mean sea level, GMSL, by the 2C (blue line), 2.7C (green line) and 3.6C (red line) forcing scenarios.  I believe that DeConto & Pollard's 2C scenario is not achievable in the real world, and that by 2100 the 2.7C and the 3.6C forcing scenario produce essentially the same amount of increase in GMSL.  Taken together with the more "Realistic" MIT analysis the DeConto & Pollard (2016 EGU) findings indicate it likely that the WAIS collapse will begin about 2050 following the current Paris Pact pledges (and also ignoring the increase in carbon emissions associated with increasing agricultural growth).

Also I note that the indicated DeConto & Pollard (2016 EGU) findings do not include Hansen et al (2016)'s ice-climate feedback and thus errs on the side of least drama (see the last two images).
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Re: Validation of GCM Models
« Reply #71 on: March 21, 2017, 03:58:29 PM »
<snip; N.>
« Last Edit: March 21, 2017, 04:05:23 PM by Neven »

AbruptSLR

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Re: Validation of GCM Models
« Reply #72 on: March 21, 2017, 04:24:11 PM »
Maybe instead of measuring increases in GMSTA, we should be focused on monitoring biodiversity loss, as without sufficient biodiversity mankind's future is in doubt.

The linked article is entitled: “Ecological recession”: Researchers say biodiversity loss has hit critical threshold across the globe".  The article references both Newbold et. al. 2016 and Steffen et. al. (2015); both of which indicate that we are already exceeding some planetary boundaries, and will soon exceed others.

https://news.mongabay.com/2016/07/ecological-recession-researchers-ring-the-alarm-as-biodiversity-loss-hits-critical-threshold-across-the-globe/

Extract: "An international team of researchers has concluded that biodiversity loss has become so severe and widespread that it could affect Earth’s ability to sustain human life.

- The researchers examined 2.38 million records of 39,123 terrestrial species collected at 18,659 sites around the world to model the impacts on biodiversity of land use and other pressures from human activities that cause habitat loss.

- They then estimated down to about the one-square-kilometer level the extent to which those pressures have caused changes in local biodiversity, as well as the spatial patterns of those changes.

- They found that, across nearly 60 percent of Earth’s land surface, biodiversity has declined beyond “safe” levels as defined by the planetary boundaries concept, which seeks to quantify the environmental limits within which human society can be considered sustainable.


See also:
Newbold, T., Hudson, L. N., Arnell, A. P., Contu, S., De Palma, A., Ferrier, S., … & Burton, V. J. (2016). Has land use pushed terrestrial biodiversity beyond the planetary boundary? A global assessment. Science, 353(6296), 288-291. doi:10.1126/science.aaf2201

http://science.sciencemag.org/content/353/6296/288

Abstract
Land use and related pressures have reduced local terrestrial biodiversity, but it is unclear how the magnitude of change relates to the recently proposed planetary boundary (“safe limit”). We estimate that land use and related pressures have already reduced local biodiversity intactness—the average proportion of natural biodiversity remaining in local ecosystems—beyond its recently proposed planetary boundary across 58.1% of the world’s land surface, where 71.4% of the human population live. Biodiversity intactness within most biomes (especially grassland biomes), most biodiversity hotspots, and even some wilderness areas is inferred to be beyond the boundary. Such widespread transgression of safe limits suggests that biodiversity loss, if unchecked, will undermine efforts toward long-term sustainable development.

&

Steffen, W., Richardson, K., Rockström, J., Cornell, S. E., Fetzer, I., Bennett, E. M., … & Folke, C. (2015). Planetary boundaries: Guiding human development on a changing planet. Science, 347(6223). doi:10.1126/science.1259855

http://science.sciencemag.org/content/347/6223/1259855
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Jim Hunt

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Re: Validation of GCM Models
« Reply #73 on: March 21, 2017, 07:31:43 PM »
<snip; N.>

I'd love to see what's on your cutting room floor too Neven!  ;D
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

AbruptSLR

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Re: Validation of GCM Models
« Reply #74 on: March 21, 2017, 07:55:11 PM »
Perhaps this thread should be renamed: "If Decision Makers Don't Care to Take Effective Action, Why Should Scientists Work to Refine Their Imperfect GCM Models?"

To bear witness. To leave a record.

As Neven pointed out, the ASIF is doing a good job of documenting the decline of the Arctic Sea Ice for the good of posterity.

Yes, and the need has never been greater with the prospect of climate science being cut off at the knees in the USA. But I am veering in the direction of policy, actions, solutions and can feel a moderator hovering over the delete button. So je suis fini.

At least we will be able to tell future generations that we were fully aware of what was happening as we carefully documented the slide down to the collapse.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

dnem

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Re: Validation of GCM Models
« Reply #75 on: March 22, 2017, 02:59:14 PM »
Obviously Jim's position is rather doctrinaire on this topic.  I don't know that much about GCMs but I tend to agree with him that at the end of the day, their utility in helping to understand the climate crisis, and respond to it, will be very limited.  For example, and yes I understand that the time scales are wrong, but the very warm non el nino driven global temps of the past two months are surprising, alarming and suggest that our overall understanding of the climate system is dangerously limited.

Have you all seen Orrin Pilkey's take on this general matter?

Useless Arithmetic
Why Environmental Scientists Can't Predict the Future
Orrin H. Pilkey and Linda Pilkey-Jarvis
Columbia University Press
https://cup.columbia.edu/book/useless-arithmetic/9780231132121

jai mitchell

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Re: Validation of GCM Models
« Reply #76 on: March 22, 2017, 03:57:45 PM »
FWIW I posted this paper on the 'science of aerosols' thread:

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0362.1

Indirect Aerosol Effect Increases CMIP5 Models’ Projected Arctic Warming

Petr Chylek et al.

Abstract
Phase 5 of the Coupled Model Intercomparison Project (CMIP5) climate models’ projections of the 2014–2100 Arctic warming under radiative forcing from representative concentration pathway 4.5 (RCP4.5) vary from 0.9° to 6.7°C. Climate models with or without a full indirect aerosol effect are both equally successful in reproducing the observed (1900–2014) Arctic warming and its trends. However, the 2014–2100 Arctic warming and the warming trends projected by models that include a full indirect aerosol effect (denoted here as AA models) are significantly higher (mean projected Arctic warming is about 1.5°C higher) than those projected by models without a full indirect aerosol effect (denoted here as NAA models). The suggestion is that, within models including full indirect aerosol effects, those projecting stronger future changes are not necessarily distinguishable historically because any stronger past warming may have been partially offset by stronger historical aerosol cooling. The CMIP5 models that include a full indirect aerosol effect follow an inverse radiative forcing to equilibrium climate sensitivity relationship, while models without it do not.
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GeoffBeacon

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Re: Validation of GCM Models
« Reply #77 on: March 22, 2017, 03:59:53 PM »
ALSR

What's the origin/copyright of those images

Geoff
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AbruptSLR

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Re: Validation of GCM Models
« Reply #78 on: March 22, 2017, 04:18:57 PM »
Obviously Jim's position is rather doctrinaire on this topic.  I don't know that much about GCMs but I tend to agree with him that at the end of the day, their utility in helping to understand the climate crisis, and respond to it, will be very limited.  For example, and yes I understand that the time scales are wrong, but the very warm non el nino driven global temps of the past two months are surprising, alarming and suggest that our overall understanding of the climate system is dangerously limited.

Have you all seen Orrin Pilkey's take on this general matter?

Useless Arithmetic
Why Environmental Scientists Can't Predict the Future
Orrin H. Pilkey and Linda Pilkey-Jarvis
Columbia University Press
https://cup.columbia.edu/book/useless-arithmetic/9780231132121

The linked article indicates that the Trump Administration considers climate research a 'waste'.

https://www.washingtonpost.com/news/energy-environment/wp/2017/03/21/trumps-budget-slashes-climate-research-but-these-scientists-still-have-a-job-to-do/?tid=ss_tw&utm_term=.1d97ff9b7bdc

On April 22nd The March for Science will endeavor to teach the Trump Administration the errors of its thinking.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: Validation of GCM Models
« Reply #79 on: March 22, 2017, 04:33:38 PM »
ALSR

What's the origin/copyright of those images

Geoff

Geoff,

I find almost all of the cartoon images that I post using GOOGLE, & thus I do not know the original source.  Therefore, if you want to retro search for the origins of the images you can use one of the following tools:

https://www.imageraider.com/
https://www.tineye.com/
https://support.google.com/websearch/answer/1325808?hl=en

Best,
ASLR
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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dnem

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Re: Validation of GCM Models
« Reply #80 on: March 22, 2017, 04:59:57 PM »
Have you all seen Orrin Pilkey's take on this general matter?

Useless Arithmetic
Why Environmental Scientists Can't Predict the Future
Orrin H. Pilkey and Linda Pilkey-Jarvis
Columbia University Press
https://cup.columbia.edu/book/useless-arithmetic/9780231132121

The linked article indicates that the Trump Administration considers climate research a 'waste'.

https://www.washingtonpost.com/news/energy-environment/wp/2017/03/21/trumps-budget-slashes-climate-research-but-these-scientists-still-have-a-job-to-do/?tid=ss_tw&utm_term=.1d97ff9b7bdc

On April 22nd The March for Science will endeavor to teach the Trump Administration the errors of its thinking.

ASLR, not sure why you append this article to my post.  Orrin Pilkey, the author of the book is "Professor Emeritus of Earth and Ocean Sciences, Nicholas School of the Environment, at Duke University, and Founder and Director Emeritus of the Program for the Study of Developed Shorelines (PSDS) which is currently based at Western Carolina University."

I certainly did not intend my post to be anti-science! I'm a PhD ecologist and will be at the march.  But that does not mean that numerical modeling has an outstanding record of success.  There is a lot more to science than just modeling and I'm not sure why you are conflating the two as somehow inseparable.  Here is some more content from his Wikipedia page:

Pilkey began his career with the study of abyssal plains on the deep sea floor. As a result of the destruction of his parents' house in Waveland, Mississippi in Hurricane Camille (1969), he switched to the study of coasts. Pilkey's research centers on both basic and applied coastal geology, focusing primarily on barrier island coasts and the effects of shoreline stabilization and development, and sea-level rise. The PSDS has analyzed the numerical models used by coastal geologists and engineers to predict the movement of beach sand, especially in beach replenishment. In general, Pilkey argues that mathematical models cannot be used to accurately predict the behavior of beaches, although they can be useful if directional or orders-of-magnitude answers are sought. In the book, Useless Arithmetic, written with his daughter, Linda Pilkey-Jarvis, they argue that the outcome of natural processes in general cannot be accurately predicted by mathematical models.[1]

AbruptSLR

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Re: Validation of GCM Models
« Reply #81 on: March 22, 2017, 05:49:24 PM »

ASLR, not sure why you append this article to my post.  Orrin Pilkey, the author of the book is "Professor Emeritus of Earth and Ocean Sciences, Nicholas School of the Environment, at Duke University, and Founder and Director Emeritus of the Program for the Study of Developed Shorelines (PSDS) which is currently based at Western Carolina University."

I certainly did not intend my post to be anti-science! I'm a PhD ecologist and will be at the march.  But that does not mean that numerical modeling has an outstanding record of success.  There is a lot more to science than just modeling and I'm not sure why you are conflating the two as somehow inseparable.  Here is some more content from his Wikipedia page:

Pilkey began his career with the study of abyssal plains on the deep sea floor. As a result of the destruction of his parents' house in Waveland, Mississippi in Hurricane Camille (1969), he switched to the study of coasts. Pilkey's research centers on both basic and applied coastal geology, focusing primarily on barrier island coasts and the effects of shoreline stabilization and development, and sea-level rise. The PSDS has analyzed the numerical models used by coastal geologists and engineers to predict the movement of beach sand, especially in beach replenishment. In general, Pilkey argues that mathematical models cannot be used to accurately predict the behavior of beaches, although they can be useful if directional or orders-of-magnitude answers are sought. In the book, Useless Arithmetic, written with his daughter, Linda Pilkey-Jarvis, they argue that the outcome of natural processes in general cannot be accurately predicted by mathematical models.[1]
[/quote]

dnem,

I apologize for any confusion that my post may have contributed to (I believe I posted too quickly); as indeed Orrin Pilkey does fight against anti-science efforts.

Here is a link to an article co-authored by Orrin Pilkey were he fights against anti-science efforts in North Carolina:

https://www.earthmagazine.org/article/denying-sea-level-rise-how-100-centimeters-divided-state-north-carolina

However, I do believe that this illustrates how complicated the challenge is of trying to motivate decision makers to follow the Precautionary Principle when denialist can just say that the model in question gives projections that are not sufficiently accurate, so they must use their own personal judgment to cancel funding to support such climate research as the current administration is doing.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson