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Comments 30451 to 30500:

30451. Rhoowl at 22:37 PM on 8 April 2015
       Models are unreliable
       

       Scaddenp

       please site some data backing your claim.....the program I use are not predicting anything that can not be predicted..... 

       i will ill give you a real world example of the climate Model 

       climate models lead to a  prediction that sea level will rise from 10 inches to Ive heard some estimates to 20 ft. This is based on the temperature increase. That's a huge error....l 

       i have to design a sea wall around NYC to prevent losS of the city. Which value to you choose. The 10 inch sea wall will cost about 100million.

       20 ft will cost 100 billion....probably not too far off with those figures Loss of the city... 2 trillion.  

       We we know sea level was about 250 ft higher than now in the past. So the 20 ft is not unreasonable.  

       Which model do do you choose

       Moderator Response:

       [JH] A range of estimates for differing scenarios do not equate to "error".

30452. chriskoz at 20:04 PM on 8 April 2015
       2015 SkS Weekly Digest #14
       

       You certainly have heard about new paper about AMOC slowdown by Stefan Rahmstorf et al. No free full text but plenty of comments on RealClimate.org and in popular press (e.g. linked to from Mike Mann's facebook).

       But did you hear about Steve McIntyre's Blunter on the subject? Worth reading, just to haver a good laugh. While trying to critique said paper, Steve confused δ15N, a proxy for water mass movement, with a proxy for temperature. Subsequently, Steve's entire critique turned invalid nonsense.

30453. scaddenp at 18:36 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl, you might also like to consider why there isnt a weather forecast that is going to predict the temperature on say June 25th 2015, let alone Dec 22nd 2015. However, several methods will give you quite accurate predictions for the June average monthly temperature and the December average monthy temperature. Ie. no amount of chaos in weather systems is going to change summer into winter. Summer is different from winter because the energy balance in temperate regions is so different. Adding CO2 is same effect on a global scale.

30454. scaddenp at 18:29 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl, instead of watching some video, try reading the detail. What you are doing is projecting what you know from hydrology model into a supposed knowledge of how climate models work from simplistic information. It seems to me that what your hydrology models have in common with weather models, is that they are both initial value problems. Climate is not. That is the point both I and Glenn are trying to make. Your 4 points are based around a misunderstanding of the models essentially. The IPCC chapters on modelling are a far better starting point then some video. We are doing our best to point you to useful information which is rather more than can stuffed into a comment reply. Now if you are going to stand by your original suppositions rather than learn new information, I dont think there is much point in continuing the discussion.

30455. BojanD at 16:51 PM on 8 April 2015
       A revealing interview with top contrarian climate scientists
       

       @CBDunkerson, I haven't said that Dana's quote was wrong. I was trying to say that Dana missed Christy's misrepresentation when he tried to debunk it. Simple check would suffice. His answer doesn't:
       
       "only 13% of participants described climate science as their field of expertise"
       
       But if you filter out all the participants that are not active climatologist, you still get "only" 78%, which is still quite a long way to oft-quoted 97%. So 150 vs. 50 years is actually very important.

30456. Rhoowl at 15:34 PM on 8 April 2015
       Models are unreliable
       

       Tom Curtis......please run a calculation based on the table for the error in the model and present it here

        

       Glenn tamblyn similar is a relative term.....ie those two are a lot more similar than say a models that attempts to predict the behavior of atoms...please direct arguments to the 4 items listed in the original posts. Disprove the statements directly

        

       hydrology has nothing to do with weather. It's purpose is to calculate quantities of water and the ability of a system to convey the water

        

       i was watching a video of how the climate models work By a scientist who uses them. He described the math of the model and basic parameters that are used for the model. He discussed how he arrived at values for the Parameters. His method was no different than anything I do to arrive at parameters for the models I operate.

30457. Glenn Tamblyn at 15:08 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl

       "Hydrology is basically a micro climate Model....you go through very similar steps to model the system....you have to use storm data to calculate rainfall"

       Nope. It's a micro weather model!

       Your hydro model is trying to model how a system responds to a set of external inputs. The best analogy with climate models would be if you were trying to predict what the storm data will be. Modelling the micro detail of behaviour from given inputs is different from modelling what the inputs will be AND broad general behaviour in response to that.

30458. One Planet Only Forever at 14:58 PM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       WRyan,

       Thankyou. Now I can appreciate why there is value in research into other materials that will work like cement powder even if they may be more expensive.

30459. Glenn Tamblyn at 14:58 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl

       "weather forecast models to climate models....although those two models are very similiar...".

       That is the nub of it. They aren't.

       Here is a simple analogy.
       I have a swimming pool in my backyard. Summer is approaching and the water level is low. So I throw the garden hose in and turn on the tap. Big pool, small hose - it will take quite a while to fill. While it is filing, my family are using the pool, getting in and out, adjusting the water level due to the displacement of their bodiea. Lots of splashing, waves, the dog jumping in after a frisbee.

       I could build two models. One model attempts to predict the detailed water level across the pool, all those waves and stuff. Pretty complex and it can only be done for short timescales. The other model attempts to predict the slower variation of the average height of the water. Much simpler; pool, hose, tap, flow rate, that's about it. Can't predict short term small scale variations but pretty good at predicting long term changes in averages.

       The first model is an initial value problem. It takes the current state of the surface of the pool, in all its messy complexity, and attempts to project it forward for seconds, minutes at best. Because over that timescale th change in total volume of water in the pool is a minor component.

       The second model is a boundary value problem. It is looking at those factors that determine the boundaries within which the smaller scale phenomena play out. Essentially in this case, how much water is in the pool.

       Although the two models are based on similar basic principals, the goal and methods of the models are very different. At its simplest, weather models are attempting to model the detailed distribution of energy within the climate system to determine local effects, but essentially assuming that the total pool of energy within the entire system is largely constant. Esentially modelling intra-system energy flows.

       Climate models are firstly modelling how the total pool of energy for the entire system changes in size over time. Then secondly they attempt broad estimations of general intra-system distributions of energy. But they can't attempt detailed estimations of intra-system distributions, only broad characteristics.

       In a simple sense, weather models model the waves, climate models model the water volume. Weather models ignore the change in water volume, climate models ignore the details of each individual wave.

30460. scaddenp at 14:20 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl - you are comparing your hydrology models to climate models. Understanding the differences between weather and climate (initial value versus boundary value) would give you some insight into the difference. While using the pinatuba data to improve aerosols is certainly a way to test and improve models, I am noting that modellers published an essentially correct prediction of what would happen with pinatuba in advance.

       The other comments were explaining what are the known issue with limits on temperature prediction (the problem of climate sensitivitiy) which explains some of the spread in model prediction. You claim models cant be trusted but I am trying to point out that

       a/ they can be trusted to predict various climate variables within useful limits. You can get your "1000s of tests" by looking at model versus observation on a whooping range of climate variables over various time intervals. AR4 has lengthy chapter on model validation.

       b/ they are the best tool we have estimate future climate change. You dont need a model to tell you that if you add extra radiation to a surface is going to warm it up but you do need one to tell you by how much.

30461. Tom Curtis at 14:11 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl @820, so you are going to stick dogmatically to the belief that the possible range of Earth temperatures is restricted to 287 K plus or minus a couple of degrees not matter how conditions at the surface, or astronomically vary?  Because the only way a comparison for accuracy matters if you are determining whether the models are any good is by comparing their predictions relative to the possible range.  They are skillful if they narrow that range, and not otherwise.  Given that the range of possible plantetary surface temperatures is known from observation to be from around 2 to around 600 K, that shows a remarkable level of dogmatism on your part. 

30462. WRyan at 13:59 PM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       @One Planet ...

       The CO2 associated wiht cement production refers to the amount of CO2 released when limestone (CaCO3) is decomposed to form lime (CaO) and CO2. The lime from this process is used to make cement.

30463. Rhoowl at 13:38 PM on 8 April 2015
       Models are unreliable
       

       scaddenp....i don't know where you see in my posts where i am comparing weather forecast models to climate models....although those two models are very similiar...

        as far as pinatubo...

       http://earthobservatory.nasa.gov/Features/Volcano/

       this explains how they used this eruption to model aerosols and test it against real world effects..it also went on to explain they ran several simulations..this is actually critical in determining the accuracy of the model...without real world test the models mean nothing..but you need many tests to ensure your model is properly working. trouble is the events that they can test are few and far between...it will take a very long time before they can refine the models to get accurate results..

       not sure what your other comments are about...never mentioned any of those either.

       Moderator Response:

       [JH] Link activated.

30464. One Planet Only Forever at 13:32 PM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       Andy, what you have presented has more worth than many 'new scientific results of investigation into isolated aspects of what is going on'.

       I understand why you restated that what you are presenting is not new science. However, you should not feel any need to provide that type of clarification. Developing better understanding is what matters. And that understanding comes mainly from a more holistic evaluation of the science to date. Better understanding can even develop from efforts to explain observations that are not clinically pure or part of a structured investigation.

       So thank you for advancing human understanding of this important issue.

       I do have one question. The reference to "Cement" seems odd. I appreciate that a significant amount of burning is associated with the production of cement powder. And cement production may stand out as significant part of fossil fuel burning. However, it seems that burning should just be included in other burning which should include the burning of fossil fuels related to wars. Which raises another question. Do the fossil fuel burning amounts reported include the burning related to war efforts? (that became two questions as I typed it).

30465. Rhoowl at 13:30 PM on 8 April 2015
       Models are unreliable
       

       http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-projections-of.html

       this give a predicted future temperature...and plus or minus therefrom...errors are in the range +/- 100% for constant to somewhat less as you move down the chart....so 75% is a reasonable figure

       these estimates are based on their models

30466. One Planet Only Forever at 13:15 PM on 8 April 2015
       A revealing interview with top contrarian climate scientists
       

       Regarding the quote from Christy copied by BojanD@4, it is important to be aware of the carefully selected misleading terms employed by the likes of Christy and avoid being lured into accepting them as valid ways of describing what is going on.

       Human impacts are not "controlling climate". They are affecting it. There is a significant difference and the likes of Christy are highly likely to be aware of the difference. And the likes of Christy will appeal to their target audience by saying things like 'those global warming fools believe humans can control the climate'.

30467. Tom Curtis at 13:11 PM on 8 April 2015
       Models are unreliable
       

       Rhoowl @815, you claim that with respect to temperature, the AR5 models show an error spread of plus or minus 75%.  That is completely false.  The models is in AR5 show a range of predicted absolute global mean surface temperature (1961-1990) from 285.7 to 288.4 K, with a mean of 286.9 K and a standard deviation of 0.6 K.  The observed values are given as 287.1 K, for an error range (minimum to maximum) of -0.49 to +0.45%.  You think there is a larger percentage error range, but that is only because values are stated as anomalies of the 1961-1990 mean, ie, they eliminate most of the denominator for convenience.  That is approriate for their studies, but if you are going to run the argument that the models are so inaccurate as to be useless, you better compare the models actual ability to reproduce the Earth's climate, not merely the exact measure of its reproduction of minor divergences in that climate.

30468. scaddenp at 12:25 PM on 8 April 2015
       Models are unreliable
       

       Rhowl - I think you should read up on actually how climate models work and particularly make sure you understand the difference between a weather forecast models and climate models.

       "When they ran the climate models to test against the piñatuba volcano I guarantee you they massaged the model quite a few iterations to achieve this result."

       I am lost to understand how you can conclude that. When Pinatuba erupted, the model prediction was made at the time (published as Hansen et al 1992). The evaluation of model prediction was done with Hansen et al 1996 and Soden 2002. I also notice that the incredibly primitive Manabe model used by Broecker 1975 is doing pretty well.

       I am not quite sure what you understand what the predictions of a climate model to mean. As the modellers would happily tell you, models have no skill at sub-decadal or even decadal prediction of surface temperature. That is basically weather not climate. In the short term, large scale, unpredictable internal variability like ENSO dominate. They do have skill at climate prediction - ie 30 year trends. That said, climate sensitivity is difficult to pin down. It is most likely in the range 2-3.5. We would desparately like to be pinned down better than that but perhaps you should look at the recent Ringberg workshop presentations to understand why this is so difficult. Nonetheless, the 2-3.5 is certainly good enough to drive policy. Whatever the shortcomings of climate models, their skill is far better than reading chicken entrails etc.

30469. Rhoowl at 11:52 AM on 8 April 2015
       Models are unreliable
       

       Hydrology is basically a micro climate Model....you go through very similar steps to model the system....you have to use storm data to calculate rainfall. Break them into isoheytals. Quantify drainage areas and land parameters. Calculate stage storage discharge relationships. Understand how the fluid mechanics affects your models. 

       In in reality the steps you go through in the analysis isnt any different than doing finite element analysis.  Even though hydrology isnt anything like finite element analysis in theory....

       ive have have worked mostly with other engineers..... I have a degree in civil engineering  environmental emphasis. 

30470. Rob Honeycutt at 11:32 AM on 8 April 2015
       Models are unreliable
       

       Rhoowl...  Have you actually tried engaging with researchers who are actively working on climate models? 

30471. Rhoowl at 10:43 AM on 8 April 2015
       Models are unreliable
       

       I would have say say that I am quite an expert when it comes to modeling real world phenomema. I used computers to model hydrology and finite element analysis regular at work.  I've been doing this for 40 years. The two applications represent  linear mathematics. The most important aspect of modeling is confidence in the model. Confidence is gained by checking the results against the real world applications. I get the luxury of testing this as soon as a month but normally with 6 months. 

       I know now the mathematics for the finite element analysis is rock solid. It's based on Hardy Cross's Method of Virtual Work. Basically just one equation. Hydrology is based on many equations. If someone else analyses the model it's normal to get results within 15 percent. This has been tested 1000's of times. Getting these results gives you high confidence.

        Different results are due to initial conditions of the model, calculation interpretation, etc. 

       but alas it's not so simple. As model complexity increases the confidence level goes down. You get unexpected results. Small changes in the model  seem to produce large changes in the results. It starts to behave non linear.

       The he modeller has a preconceived notion as what to expect from the result. When the results are not what you think they should be you will test this by altering the conditions. This is performed in all modeling. When they ran the climate models to test against the piñatuba volcano I guarantee you they massaged the model quite a few iterations to achieve this result. In reality this give you a better understanding of how the model works. 

       One argument you hear is Gigo. It's my belief this is not accurate And a bad argument. Believe me...the modeller spends a large amont of time to get all the parameters as precise as he can to ensure the best result. 

       This is my believe that the climate models can not be trusted

       1 the results of all the models indicate a wide spread. The ipcc show predicted temperature errors is in the +/- 75 percent range.  This would yield a low confidence. If I got results in my work for that spread I would trash the result and use another method.  In fact it would be nearly impossible to design anything based on that result.

       2. The model has not been tested against enough real world events to judge the reliability of the model. It takes 1000s of tests to ensure model reliability.  

       3. The non linearity signficantly complicates the model performance. 

        4 model complexity increases errors through unexpected results. 

30472. CTG at 08:30 AM on 8 April 2015
       A revealing interview with top contrarian climate scientists
       

       I always laugh when pseudo-skeptics reject IPCC projections of future climate scenarios because they are based on "GIGO computer models", but then in the next breath claim that UAH is the most reliable temperature series, even though it is also based on a "GIGO computer model". In fact, UAH gives a really good example of the GIGO problem - by not accounting for decline in satellite orbits, they were effectively feeding garbage into the model, so it spat garbage out, in the form of a cooling trend that didn't exist.

30473. uncletimrob at 06:42 AM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       Thanks for the very clear and might I say unusual display of this data.  Another "must read" for my students.

30474. jja at 06:11 AM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       Great graphics!  I was considering the Anthropocene discussion.  It seems to me that the geological record will record a deposit layer of plastic and some suggest that it should be called the plasticene.
       
       However, I believe that the biological extinction record will be clear, we have already embarked upon the 6th great extinction event.  There is not a single realistic mitigation scenario that will not lead to catastrophic species declines on land in in the sea.  
       
       In view of this, instead of calling this period the Anthropocene, it seems that the short-lived duration of human existence is only a precursor to the apparently intentional decimation of, depending on our mitigation efforts, up to 95% of all life on planet earth through this process of self-consumption and the subsequent immolation of the biosphere. 

       With the real beginning of this extinction event happening near the mid to late 1970s, it seems appropriate to consider the teachings of the Hopi elders who saw the successful inhabitation and subsequent fall of SkyLab in 1979 as the fullest sign of the end of this age of man.

       
       
       And this is the Ninth and Last Sign: You will hear of a dwelling-place in the heavens, above the earth, that shall fall with a great crash. It will appear as a blue star. Very soon after this, the ceremonies of my people will cease.
       
       http://www.welcomehome.org/rainbow/prophecy/hopi1.html

        

       

       Future archeologists will know our conscious ability and see how we have destroyed this world.
       
       The new period we have entered isn't the anthropocene, it is the deleocene.

       The Latin phrase for Wipe Out is deleo. The Latin phrase deleo is defined as (deletum) to destroy, wipe out, erase.

       source:  http://www.nap.edu/openbook.php?record_id=12501&page=R3]http://www.nap.edu/openbook.php?record_id=12501&page=R3

30475. ubrew12 at 05:02 AM on 8 April 2015
       The history of emissions and the Great Acceleration
       

       If I were a teacher I would definitely direct my students to your clear and fascinating examination of this topic.  Thanks!

30476. Walla at 02:47 AM on 8 April 2015
       The Good, The Bad and The Ugly Effects of Climate Change
       

       Dear Skeptical Science... I am not a scientist, but a Musician, wich means I will look more for the romantisized version of the facts :)... that being said:

       This is dark, really dark. I realize you only write the facts, but it's still quitte depressing. So my question is: is there a solution to all of this (and no, I do not expect there to be an easy answer), especially considering there are a lot of scientist on this blog, and most can't seem to agree with one another.

       Moderator Response:

       [TD] Not a "solution" in the sense of preventing a global temperature rise of at least 2 degrees.  But technologically and economically it is feasible to prevent a rise above that. (Read the Basic, Intermediate, and Advanced tabbed panes there.)  The impediments are political.

30477. Tom Curtis at 01:28 AM on 8 April 2015
       We must defend science if we want a prosperous future
       

       ryland @18, Abbot proudly proclaims his religion, and seek political advantage from doing so.  It is only right that he be accordingly judged on the complete inconsistency between Christian ethics, and those of his government's policies.

       Moderator Response:

       [JH] I have deleted Ryland's response to this comment because this "off-topic" discussion has run its course. It's time for both of you to cease and desist.

30478. Composer99 at 00:01 AM on 8 April 2015
       A revealing interview with top contrarian climate scientists
       

       Hmph. Spencer has some nerve white-knighting for the global poor, seeing as atmospheric pollution from coal (beyond greenhouse gas pollution) has terrible effects on health and productivity, and of course the consequences of global warming will fall hardest upon the poor, as described previously here at Skeptical Science.

30479. ryland at 23:38 PM on 7 April 2015
       We must defend science if we want a prosperous future
       

       Tom Curtis.  Thank you for your lengthy reply which  I will not emulate.  Regarding your comment "slamming the Labor party" that is merely a matter of view.  What you regard as slamming I regard as providing true facts that can be verified.  With regard to the GFC there are many reports that claim Rudd did  not save Australia.  Below are three references (I can obtain many more of course) to such reports

       http://tinyurl.com/lsoe65c; http://tinyurl.com/kee7kq9 and http://tinyurl.com/kn6lfdc.  The last one of these is particulary noteworthy as it is from the Guardian a publication that certainly does not support the LNP.

       Due to OT concerns I will not address the rest of your  comments except to note your bringing Abbott's  religion into the discussion is somewhat tacky 

30480. billthefrog at 22:31 PM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       In comment #2, Phillippe makes reference to a certain Frank Lutz. This is a name that will be familiar to many readers of SkS.

       For those newer to the game, Lutz is (was?) a political advisor, amongst whose illustrious contributions to the welfare of the planet, was the infamous "Lutz Memo". This, basically, was a playbook for the Grand Old Party advising how to deal with questions pertaining to the environment.

       For those wishing to take a quick dekko, it can be seen here.

       Happy reading

       cheers    bill f

30481. CBDunkerson at 21:52 PM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       BojanD, ummm... the "50 years" bit is a quotation >of< Christy.

       So yes, you are correct... the study actually said 150 years, but it was Christy who got it wrong, not Dana.

30482. BojanD at 20:51 PM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       "Is man the dominate controller of climate over the last 50 years"
       
       

       Actually the question was about the last 150 years, which makes quite a difference as far as attribution statement is concerned. The authors of the study suspected that this was the reason for some of the discrepancy. Interesting that Dana has missed this. Not surprising that Christy hasn't.

30483. MA Rodger at 18:42 PM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       Christy does leave one statement hanging in the air. He says:-

       "People who come out with different views in their organizations (ie the NASA, NOAA, EPA, DOE) are found to be squashed."

       If they are "found", we can give them names. Who are these "people"? Do tell us John Christy!! Demonstrate you speak grown-up words and not puerile nonsense!!

30484. OfNoAccount at 17:54 PM on 7 April 2015
       We must defend science if we want a prosperous future
       

       I am old enough to have passed the obstacle of counter-intuitive propositions being closer to the way things are than the common sense consensus establishes.
       The observations and deductions made from them and the mathematical modelling of them was bread and butter for my generation.  Heliocentrism, elliptical orbits and so forth were scientific orthodoxy.  But they are all wrong in fact.  The sun is moving rapidly, the planets are going around it corkscrew wise and none are actually undergoing Newtonian motion at all.  The material universe is not matter, energy and space.  If we exist at all it is in a space/time continuum pervaded by the presence of stuff of which we are made and which can only be located by probability functions and field vectors and these omit the vast majority of the existent which we think of as having fallen into black holes or have to use poetry to name as dark matter and dark energy.

       By now, however, I have a different problem.   I am not confident that what is being published as science is truthful.  A vast proportion of the purported science is opinion and/or interpretation which fails to be matched by the data and analysis which is used as the reason justifying publication and demanding serious consideration.

       In my youth, original science was done in Universities and pathways were followed for the intrinsic interest or importance by passionate investigators who distinguised between findings and theories easily and automatically.  Now it is done by Santa's little helpers in the employ of impersonal institutions who have ulterior motives for directing which questions to pursue and vested interests in either positive or negative results depending on the significance of their economic interests or academic status or public esteem.

       Good work is hidden as commercial in confidence secret or so geopolitically sensitive as to be state secrets - (military mathematicians disappear from the maths community never to be heard of again, a personal experience).
       One comentator wonders if climate denial should be outlawed as immoral, I match that by recommending the opposite that human induced biosphere threatening global warming from use of fossil fuel urgency is like calling out fire in a darkened cinema.

       Where does responsibility for this lie and how might this be addressed?

       Moderator Response:

       [PS] Welcome to skeptical Science. Please take some time to read the Comments policy, and in particular note the prohibition on accusation of fraud or dishonesty. I frankly find your views somewhat extraordinary and rather than speculate on what informs your opinion, I would kindly ask you to provide evidence to back your assertions. Since this is a science site, then perhaps you could in particular provide an example of "purported science is opinion and/or interpretation which fails to be matched by the data and analysis" and do so on an appropriate thread.

       Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

30485. Glenn Tamblyn at 17:03 PM on 7 April 2015
       It hasn't warmed since 1998
       

       Further to an earlier comment by Peter99

       "Seems to me that AGW is unfalsifiable. When temperatures were rising in the 1990's that was proof of AGW, but now that temperatures have plateaud so far this century, the "proof" of AGW moves elsewhere."

       You seem to be misunderstanding falsifiability. Key to it is the making of reasonable predictions, understanding the accuracy with which the prediction can be made. Then evaluating all the available data to compare with the prediction. Several key things need to be considered:

       Is the theory making a simple black and white prediction; is that a valid statement of the theory? Or is it predicting results within a range of values?

       What range of results constitute validation of a theory? What range of results an invalidation? Is there a black-and-white distinction between the two or shades of grey?

       Is the nature of the theory such that a failure to completely meet every prediction should be taken as an indication of the total failure of the theory. Or are there degrees of failure and degrees of prediction.

       Falsifiability is a great idea but when treated as too black-and-white a criterion it becomes practically useless in many real world scientific contextx. Very few situations lend themselves to black-and-white arguments

       So to your question: "One last question...If global temperature increase stays at the present near zero rate until 2100, will the theory of AGW need revision?"

       Yes.

       But which part of the theory? The part of the theory dealing with Radiative Heat Transfer, Planetary Energy Balance, the Greenhouse Effect etc.? Or the part of the theory dealing with Oceanography, heat distribution in the ocean, ocean overturning time etc?

       What if air temperatures don't rise by 2100 but ocean heat content, sea level etc. do rise? Which part of the theory needs to be revised?

       You seem to be trying to reduce a complex question down to the idea of the simple black-and-white falsifiability of a single, indivisible theory. When the reality is of a set of multiple intersecting theories, each contributing to the overall conclusion, and complex layered observations that they are being tested against.

       Popperian Falsifiability is an important ideal in science; as an ideal! Highly applicable in simple contexts, less useful in more complex situations.

       As with most areas in life, basic principles derived from a black-and-white world view only become useful when translated into a shades-of-grey world view. Till then they remain mere idealisations.

30486. Glenn Tamblyn at 16:37 PM on 7 April 2015
       It hasn't warmed since 1998
       

       Peter99

       You left off some other quotes from the piece:

       "Scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, analyzed satellite and direct ocean temperature data from 2005 to 2013 and found the ocean abyss below 1.24 miles (1,995 meters) has not warmed measurably. Study coauthor Josh Willis of JPL said these findings do not throw suspicion on climate change itself.

       "The sea level is still rising," Willis noted. "We're just trying to understand the nitty-gritty details."

       "Coauthor Felix Landerer of JPL noted that during the same period warming in the top half of the ocean continued unabated, an unequivocal sign that our planet is heating up. Some recent studies reporting deep-ocean warming were, in fact, referring to the warming in the upper half of the ocean but below the topmost layer, which ends about 0.4 mile (700 meters) down. "

       Note that these quotes are attributed to the study authors. Your earlier quotes in contrast are commentary by the author of the NASA news release with no attribution to the actual study authors. 
       
       You said there was a NASA report. Rather it looks like there was a study conducted by scientists from NASA and published in the scientific literature in the normal way. Then the NASA media unit published a news report highlighting the study. Not a NASA report. And maybe the NASA journalist got some stuff wrong!

       Like in particular, that the common suggestion of warming occurring 'deeper' has always referred to the lower levels of the upper half of the ocean. Specifically below 700 meters but above 2000 meters. There has been no significant suggestion that meaningful warming is occuring in the lower half of the ocean, below 2000 meters. And this study provides support for that view.

30487. Tristan at 15:25 PM on 7 April 2015
       It hasn't warmed since 1998
       

       It doesn't really matter whether or not you think my explanation is 'one of sixty or so'. There are numerous oscillatory systems at play in weather, from the very short term (day/night) through seasonal differences and the decadal scale PDO (which is responsible for a lot of the year to year climate variation).

       You need to learn the meaning of statistical significance before you start making claims about it, lest you look silly.

       The trend (GISTEMP) for 1995-2010 is

       +0.138 +/- 0.147 c/dec.  Because the number after the +/- (the 2 sigma error) is larger than the number before it (the trend), you cannot statistically exclude zero.

       The trend (GISTEMP) for 1995-2015 is

       +0.113 +/- 0.092 c/dec. Because the error is smaller than the trend, you can statistically exclude zero.

       Hence. To 2010 there is not 'statistically significant warming' and to 2015 there is.

30488. PhilippeChantreau at 13:39 PM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       Nothing new under the sun. In the old Soviet Union, when asked some questions about a certain incident, leaders responded "in our camp, airplanes don't crash." In the denial camp in the US nowadays, it's "you can't say the word se-level rise." Exactly identical attitude, but even worse. It's not like saying "airplanes don't crash", it's more it "you can't say the word plane-crash." Beyond insane.

       It is especially ironic that, after all the grief climate scientists received in the Bush administration, the failed attempts from Cuccinelli to intimidate Mann and the nonsense from certain coastal states, S&C have the nerve to say that skeptics are being slienced. This is another tried and true method from the Lutz/Rove manual of practical BS for mass manipulation. Accuse your opponent of doing exactly what you're doing, preferably send the accusation first; if not, just be really loud and whiny about it. Works every time. The BS wars in the US have got to the point where it takes a fair level of sophistication, research and time to figure out the reality, none of which is within reach of the vulgum pecus. The natural result is a reinforcement of the existing tendency to take refuge in what we prefer to believe anyway. Reality has no chance in a debate these days. It will win eventually, in the most painful fashion.

30489. citizenschallenge at 13:34 PM on 7 April 2015
       We must defend science if we want a prosperous future
       

       If you found this interesting you'll want to read Lawrence Torcello I believe he does a better job of cutting to the chase:

       March 13, 2014 also at The Conversation

       "Is misinformation about the climate criminally negligent?"

       https://theconversation.com/is-misinformation-about-the-climate-criminally-negligent-23111

       Climate denial funding

       We have good reason to consider the funding of climate denial to be criminally and morally negligent. The charge of criminal and moral negligence ought to extend to all activities of the climate deniers who receive funding as part of a sustained campaign to undermine the public’s understanding of scientific consensus.

       Criminal negligence is normally understood to result from failures to avoid reasonably foreseeable harms, or the threat of harms to public safety, consequent of certain activities. Those funding climate denial campaigns can reasonably predict the public’s diminished ability to respond to climate change as a result of their behaviour. Indeed, public uncertainty regarding climate science, and the resulting failure to respond to climate change, is the intentional aim of politically and financially motivated denialists.

       My argument probably raises an understandable, if misguided, concern regarding free speech. We must make the critical distinction between the protected voicing of one’s unpopular beliefs, and the funding of a strategically organised campaign to undermine the public’s ability to develop and voice informed opinions. Protecting the latter as a form of free speech stretches the definition of free speech to a degree that undermines the very concept.

       What are we to make of those behind the well documented corporate funding of global warming denial? ...                  Lawrence Torcello

       http://whatsupwiththatwatts.blogspot.com/2015/04/premeditated-climatescidenial.html

30490. Tom Curtis at 08:04 AM on 7 April 2015
       We must defend science if we want a prosperous future
       

       ryland @12, I almost did not respond to chriskoz because doing so was a clear violation of the comments policy requirement of "no politics".  Responding to you will clearly violate that rule even further, especially if I give the sort of detailed response that is appropriate.  None-the-less I feel compelled to respond to your claims lest my lack of response falsely indicates an inability to respond.  Out of respect to the comments policy, however, I will limit myself to bullet points rather than a full rebutal:

       • As Tristan has already noted, you ignore the content of my claims so that you can slam the Labor party.  You also ignore that I spoke regarding policy rather than administration of policy (where I do not rate the Rudd/Gillard governments highly, though that are better than the Abbot government in that regard).
       • The cash handout was a direct response to the GFC, being designed to maintain consumer confidence in the face of the GFC to avoid a collapse of retail sector employment.  It was successful in its aims.  Suggestions that the mining boom helped in that specific aim are absolutely refuted by the fact that after the GFC, the mining boom created pressure on the retail sector due to the "two speed economy".
       • The "Pink Batts" scheme represented only 10% of a larger scheme that was a resounding success overall.  Further, the "Pink Batts" scheme is considered a disaster largely due to the deaths of four people, purportedly due to maladministration by the Federal Government (despite the WHS aspect already being covered by state legislation).  Of those deaths, the first occurred when an experience electrician electrocuted himself.  Given that he was an experienced electrician, the claim that his death was due to insufficient training is absurd.  The second was when an apprentice carpenter ignored regulations requiring the use of plastic (non-conductive) staples and electrocuted himself by using his own metal staples.  When somebody ignores regulations and training and thereby gets themselves killed, that is not the fault of the regulatory body.  The third was a person electrocuted because they made contact with a screw that prior workers (ie, prior to the installation he was involved in) had driven into electrical wires, ie, of an unfortunate happenstance that training would not have helped avoid.  The forth was of a person "filling in for his mate" who therefore did not have the training the scheme required, who having suffered heat problems and being asked to wait outside of the roof cavity by his supervisor because of it, went back into the cavity unknown to anybody and died of hyperthermia.  The only way the Federal government could contributed to avoiding these deaths would have been by duplicating state regulations, and intensively regulating the activity - both policies their critics strongly object to - objections, however, that seem to evaporate when they had an opportunity to make political hay out of the Pink Batts scheme.  This is not to suggest the scheme was perfectly administered (it was not).  However, claims that it was an "unmitigated disaster" depend either on ignorance, or unprincipled ignoring of their fundamental political principles by those critics.
       • The Building the Education Revolution (BER) scheme was a scheme to maintain employment in the building sector durring the GFC.  Benefits to education were explicitly a secondary consideration, and opportunistic.  Despite that, over 98% of the facilities built under the scheme were welcomed by the schools in which they were built, and improved the facilities available at the shool.  In about 1% of cases this was not the case.  That 1% was focussed on by critics, who ignored the successes in what was overall an exemplary scheme.  Further ignored by critics was that even the failures came about because of cumbersome state based administration of the scheme, especially in NSW.  Again, the Federal government could have avoided those problems only by microregulation and duplication of state based regulation and bureacracy.
       • Finally, the assylum seeker policies inheritted by the Abbot government were less onerous versions of those inherited by the Rudd government from the Howard government (in which Abbot was a minister).  Your little sally without mentioning that fact is somewhat duplicitous.  Further, I do not consider increasing deaths of persecuted people in the land of their persecution a preferrable outcome to the lower number of deaths by drowning resulting from people attempting to find refuge in Australia.  Nor (and this is a value judgement) do I rate the importance of the suffering of people on a scale depending on the colour of their skin, or the remoteness from our shores.  Therefore I consider the current international system in which the vast majority of refugees are left to rot in third world countries in inadequate facilities acceptable.  For that reason I applaud the Abbot governments increase of the standard refugee intake (inadequate as it still is), but deplore the assylum seeker policy of both major parties.

       I will not further respond on any of these issues due to the comment policy.

30491. Tom Curtis at 07:18 AM on 7 April 2015
       Climate sensitivity is unlikely to be less than 2C, say scientists
       

       Theo168 @7, you are assuming that the authors are more influenced by political expediency than by scientific merit.  If they are more influenced by the later, it is the scientific merit of the comments they recieve that will influence them the most.

       You are also neglecting that my comment @6 was a rebutal of a claim that governments control the contents of the IPCC reports, and also that I had previously rebutted (@4) the idea that the reports significantly differ from the consensus position of relevant experts.

30492. jackdale at 07:09 AM on 7 April 2015
       A revealing interview with top contrarian climate scientists
       

       Some more telling statistics on the AMS survey.  

       only 4% of the participants said global warming is not happening 

       only 5% of the participants attributed global warming to mostly natural causes

30493. Stephen Baines at 04:55 AM on 7 April 2015
       Sea Level Rise is Spiking Sharply
       

       What is more interesting is that the Equatorial heat content has risen now to a level similar to that seen last year.  NOAAs says there is a greater than even chance the El Nino holds through the summer.    In fact, this uncertainty reflects a strong split between statistical models, which suggest a return to neutral conditions, and dynamic models, which generally predict emergence of strong El Nino conditions late spring to early summer.

30494. Stephen Baines at 04:42 AM on 7 April 2015
       Sea Level Rise is Spiking Sharply
       

       OK...now NOAA is officially categorizing this as an El Nino period...by the skin of it's equatorial teeth.

30495. Theo168 at 03:35 AM on 7 April 2015
       Climate sensitivity is unlikely to be less than 2C, say scientists
       

       Tom Curtis, you are confusing influence with control.

       The response to feedback from a Govt body will more than likely be different than from a random self identified "expert".  You don't have to be 'in-control' to get what you want.

30496. DSL at 00:41 AM on 7 April 2015
       It hasn't warmed since 1998
       

       Peter, you're also letting others lead you on.  Read the full discussion surrounding those quotes:
       
       

       1. Trenberth, when using the word "travesty," was engaged in discussing his recent paper "An Imperative for Climate Change Planning: Tracking Earth's Global Energy" (Trenberth 2009).  Here's the abstract:

       "Planned adaptation to climate change requires information about what is happening and why. While a long-term trend is for global warming, short-term periods of cooling can occur and have physical causes associated with natural variability. However, such natural variability means that energy is rearranged or
       changed within the climate system, and should be traceable. An assessment is given of our ability to track changes in reservoirs and flows of energy within the climate system. Arguments are given that developing the ability to do this is important, as it affects interpretations of global and especially regional climate change, and prospects for the future."
       
       In other words, Trenberth was calling our ability to track energy in the climate system a "travesty."  We need better measures of deep ocean heat content, for example.  If you just read the quote from some "skeptic" site, then shame on you for not digging for context.

       2. Phil Jones.  He was answering honestly.  The trend was not statistically different from zero.  It was also not statistically different from the expected trend.  Guess how it was portrayed by those who wish to turn doubt into profit?  Again, if you took it hook, line, and sinker, without checking out what "statistically significant" means, and without taking Jones at his word in response to the flabber that followed, then shame on you.

       3. Hansen.  Be careful: "slowdown in the growth rate of net climate forcing" is not equal to "global warming has stopped/slowed."  It may mean that forcing from greenhouse enhancement remains steady but aerosol forcing has increased.  What does it mean to you, after having read Hansen's full statement?  Or have you read it . . .

       4. Von Storch has already been addressed. 

30497. DSL at 00:27 AM on 7 April 2015
       It hasn't warmed since 1998
       

       And yes, Tom, I know we can argue about what exactly is contained within the "theory of AGW," but I don't think it applies in this case.  I think it's best to establish that the greenhouse effect is pretty solid, and that we are enhancing that effect.  If Peter will oblige us by accepting those two propositions, we can move much more quickly into areas with greater uncertainty (e.g. modeling).  I would like Peter to do what many "skeptics" find so hard to do: recognize and accept the basic science.

30498. DSL at 00:21 AM on 7 April 2015
       It hasn't warmed since 1998
       

       Peter: "So my question is, if the pause continues, how many years must pass before it’s conceded that “something is fundamentally wrong with our climate models”? In other words, if the pause continues for n years then can that then be classed as a falsifiable criterion for AGW?"
       Peter, let's not be ham-fisted about this, eh? The greenhouse effect is extremely well-established. It's been directly measured from the surface. And I don't think you want to argue that humans aren't responsible for most, if not all, of the increase in atmospheric CO2 over the last century. The general theory of AGW is not going to be falsified by the trend in surface temperature. CO2 does what it does. We have done and are doing what we've done and are doing.

       What the trend in surface temp tells us is how well we've modeled energy circulation for Earth's climate system. It also helps us understand climate sensitivity past and present. If the surface trend goes flat or negative for thirty years, then it will indicate that we are missing a major factor in the climate process. If ocean heat content also goes flat for thirty years, then we've likely completely misunderstood the process.

       Note that OHC (in the link I posted earlier) in no way shows a "pause." The oceans are still rapidly accumulating energy, and the oceans are 93%+ of the thermal capacity of the climate system.

       As Tom has pointed out, and as several of your quotes--in fuller form--point out, drawing conclusions from a surface trend is tricky business. When does the thirty-year trend start? 1998? Not statistically sound, as Tom has pointed out. Trend is negative from x to y (a period of between 6 and 10 years)? So what? Happened before, as I pointed out. Trend is not statistically significant? Ok, but what exactly does that mean? Does it mean that the trend is not statistically distinguishable from zero, or does it mean that it's not statistically different from well above the expected trend? Both. It doesn't mean there's no trend (i.e., it doesn't mean what you think it means).  

       Your interest seems to be "falsifying AGW" rather than understanding the science.  You shouldn't attack something you don't understand.  Understanding the theory of anthropogenic global warming by working backward from the surface trend is a bad idea.  You should start with the basics.  When you start with the basics, you'll know what is "settled science" and what is still being actively researched.  

       In this latest comment, you're basically repeating the same argument. Tom has answered the question you just asked, and in detail.  If you repeat it again, without recognizing what has been said in response, your posts will be in violation of the SkS posting policy.

30499. Tristan at 23:48 PM on 6 April 2015
       It hasn't warmed since 1998
       

       Peter, there is no 'pause' in any meaningful sense. CO2 hasn't magically stopped re-radiating thermal radiation.

       Tom's graph demonstrates the illusory nature of the pause. Things can look like 'pauses' when you have an oscillation (weather) overlaid on a gradient (climate). Just because you can draw flat or negative lines starting from certain peaks to certain troughs doesn't mean that the underlying gradient has changed.

       
       You will note that if you asked that exact question of Phil Jones today, he would be able to answer "since 1995 there has been statistically significant warming in the Surface Temperature Records". At some point within the next 5 years, you'll be able to say the same thing about 1998, and then the so-called skeptics will have to completely reject the surface temperature records, as they will no longer be convenient. Is that the team you want to be on, Peter?

        

30500. wili at 22:11 PM on 6 April 2015
       2015 SkS Weekly News Roundup #14B
       

       "Climate sensitivity is unlikely to be less than 2C, say swientists"

       Please correct this article title (unless you're talking about people who study 'swien'!?).

       Moderator Response:

       [BW] Thanks, Fixed!

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