Arguments
Recent Comments
Prev 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 Next
Comments 35251 to 35300:
-
Russ R. at 10:02 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
scaddenp @47,
I'll withdraw my "cherry-picking" comment for two reasons:
1. It was never intended as an allegation of fraud, rather of selection bias, in that their selection criterion for the "best" models (agreement by chance with ex-post ENSO trends) was likely correlated with the model output being used to assess of predictive skill (global temperature trends). The higher the correlation, the more the method would treat luck as skill.
2. On further review it turns out that these two items (NINO3.4 trend and global temperature trend) are not nearly as correlated as I had imagined. When looking at 15-year trends, the correlation coefficient is only 0.13 between them.
So... withdrawn.
-
Joel_Huberman at 09:58 AM on 24 July 2014Seal of approval - How marine mammals provide important climate data
Thanks, BaerbelW and Anne-Marie Blackburn, for a very interesting post!
-
scaddenp at 09:56 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
This is my personal view on this paper. The paper takes a novel way to test the hypothesis that poor match between ensemble mean and observations is due fact the model mean includes many different states of ENSO whereas observations a "one member of the ensemble". The paper does demonstrate that a mean created from runs which are in phase with actual state are a closer match to observed global temperature. This does underline the importance of ENSO on short term global temperatures. I am sure everyone is very surprized by that result (not!).
I do not think the paper can preclude (and the authors make no such claim) that there are other problems with the modelling. Beyond well-known problems with models, the question about accuracy of aerosol forcing seems to need more data (at least another year) from the Argo network. There could obviously be other errors and inaccuracies still hidden in modelling of feedbacks.
However, what you can conclude is that there is not as yet conclusive evidence of some unknown failure in the models on the basis of a mismatch between ensemble mean and observations: It would appear that issue of ENSO is quite sufficient to explain the mismatch in global surface temperature for such a short term trend.
-
scaddenp at 09:31 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
" A minor concern is that the selection criteria (NINO3.4 Index trend) is correlated with the outcome (global trends), meaning that to some extent the study will suffer from retrospective selection bias (which I called "cherry-picking")."
This comment makes no sense. Cherry-picking is a very serious allegation to make about a published paper since it implies fallacious argument with the underlying suspicion of scientific fraud. Unsubstantiated accusations like this are not tolerated by the comments policy. I ask again, how could you test their hypothesis with this data in a way that doesnt use that selection method?
To your points:
1/ The "good" is being used to describe the pattern (not cell-by-cell estimate) compared to the anti-phased ensemble.
2/ It is no news to climate science that models are poor at regional level. Eg see Kerr (2013) (which was discussed at Realclimate here.)
However it does not follow that "if they cant do regional, then global is wrong". This is discussed in detail in papers referenced in the RealClimate article.
-
Russ R. at 07:21 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
scaddenp@45,
"I am not totally sure about what question Russ R refers to, but I believe the question may @8. This I answered directly in here..."
Apologies, I didn't realize that the first paragraph of your comment @10 was actually a response to my oft-repeated question (@1, @3, @8, and again @21)... which is why I kept on asking, with increasing frustration.
Since you've been kind enough to answer me, I'll be happy to answer your question @30. (I'll put that response its own dedicated comment next.)
"I think Russ is interested in pushing the point that even the selected scenarios do not match observations particularly well in absolute terms"
The point I've been pushing is this... the paper claims that the "in-phase" models accurately predicted global warming over the 15-year time period AND that the models "provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns".
I don't take major issue with the first part... the average trends. A minor concern is that the selection criteria (NINO3.4 Index trend) is correlated with the outcome (global trends), meaning that to some extent the study will suffer from retrospective selection bias (which I called "cherry-picking").
But claiming that the models made even "good" spatial trend pattern predictions appears absolutely wrong, as shown by the authors themselves (Figure 5.) where they show a regional comparison of model predictions (best and worst) vs. observations. The relationship between even the "best" model predictions and the data is backwards in every ocean region except for the one region used for selection of the "best" models.
So, two points to make here.
- The claim that the "in-phase" models made "good" predictions of recent spatial trend patterns appears to be invalidated by Figure 5.
- Even if they "in-phase" models got the global trend right on average, that feat looks more like luck than skill when they got every regional trend wrong.
-
scaddenp at 06:28 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
I am not totally sure about what question Russ R refers to, but I believe the question may @8. This I answered directly in here though Russ obviously understand spatial pattern differently from me and the authors.
I think Russ is interested in pushing the point that even the selected scenarios do not match observations particularly well in absolute terms (does he really expect any ensemble to do that??) but seems much interested in this rhetoric point than in the more interesting questions as to why and the relative matching skill of phased and anti-phased scenarios.
-
Charlie A at 06:19 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
The abstract is only 5 sentences long. The last two sentences (with my bolding) are:
"We present a more appropriate test of models where only those models with natural variability (represented by El Niño/Southern Oscillation) largely in phase with observations are selected from multi-model ensembles for comparison with observations. These tests show that climate models have provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns."
So the authors selected a subset of the model runs and compared them to observations. They found that this subset of model runs provided good estimates for Pacific spatial trend patterns.
Can someone clarify what is meant by "Pacific spatial trend patterns" in this context. Do the authors mean basin-wide trend patterns; trend patterns in the same Enso 3.4 area used to select the subset of models; something else entirely?
-
Rob Painting at 06:07 AM on 24 July 2014Seal of approval - How marine mammals provide important climate data
Chris - They are two different things. The ocean has the capacity to hold a thousand times more heat than the atmosphere, but we live on a rapidly rotating sphere where the bulk of incoming energy from the sun is received in the tropics.
In practice, because of Earth's geometry, the shape of the ocean basins, the percentage of land vs ocean in the tropics, and a host of other considerations, we're never going to actually see a thousand times more heat in the ocean than the atmosphere.
The 93.4% figure is the percentage of heat going into the ocean, whereas the specfic heat capacity is an idealized scenario.
-
Chris Crawford at 05:32 AM on 24 July 2014Seal of approval - How marine mammals provide important climate data
Actually, I have a serious question, concerning the graph of ocean heat versus atmospheric heat. Long ago, I did the calculation of the relative heat capacities of the oceans and the atmosphere and came up with a result of 99% of the net heat capacity of the two was held in the oceans. I have seen other calculations yielding 99.9%, 99%, and even 90%. Figure 1 suggests 90%. I realize that there are complexities arising from freshwater, and the amount of water vapor in the air, especially involving the latent heat in water vapor. Can somebody please explain the basis for the different answers?
-
Chris Crawford at 05:22 AM on 24 July 2014Seal of approval - How marine mammals provide important climate data
I'm sorry, but that seal looks very much like she's saying "Does this hat make me look fat?"
-
MA Rodger at 04:53 AM on 24 July 2014Why we care about the 97% expert consensus on human-caused global warming
troyvit @6.
Your linked item "The Control Group Is Out Of Control" is mainly about parapsychology and the examples it looks at in wider science are still pretty soft psychology (eg social priming) plus the odd reference to pharma research. The argument offered by your linked item is that a subject that is so obviously crackpot like parapsychology must then be subject to much more suspicion, and thus much higher levels of checking, if parapsychology can fail to spot so much unreplicable work, what of other sciences where suspicion and checking would be less? Is it valid to conclude as the item quotes "It just means that the standard statistical methods of science are so weak and flawed as to permit a field of study (parapsychology) to sustain itself in the complete absence of any subject matter."?
Well, the level of defense in psychology/psychiatry literature appears to be the problem and one that doesn't extend to geosciences & enviro-eco science, as this graphic from a subsequently-linked Nature article illustrates. (The position of Material Sciences second from bottom may be to do with initial results being far more strongly based in such a physical area of study.)
-
Bob Lacatena at 04:34 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
RussR does not appear to understand the most basic aspects of the paper, or of climate modeling. His tone and anger suggest that his misreading / misinterpretation of the subject and paper is either consciously or unconsciously willful.
I would suggest that arguing with him is a complete waste of time. Certainly, correct his mis-statements, for the sake of lurkers and other readers, but engaging him directly is pointless.
-
dhogaza at 02:47 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
"ENSO-like variations in the models differ in phase based upon the individual runs."
I think a couple of people posting here probably haven't figured out that a finite number of runs (I think a few dozen are typical) which exhibit internal variability means that it's largely chance as to which model runs (and therefore which models) will be in phase for the historical recent ENSO history for each 15 year period.
Run each model a few more dozen times, select according to their algorithm in the same way, and for each 15 year period the model's whose runs match the historical 15 year period will differ ...
I think it's a rather ingeneous approach. Some model teams can (and have) performed hindcast runs plugging in known values for natural variability but that's expensive, much more expensive than this approach, and can't be done external to the team (unless you happen to have a massive supercomputer sitting in your basement).
-
Dikran Marsupial at 02:19 AM on 24 July 2014Why we care about the 97% expert consensus on human-caused global warming
troyvit academics have very little to gain by following the crowd, we are generally a rather disagreeable lot that spend our time finding fault with the work of others (and more importantly trying to do better). To get highly cited papers, you need to find out something that people don't already know, and the best way to do that is to be different.
The reason that we have a consensus is not because we are all following the crowd, but because reality places constraints on which hypotheses are plausible. The reason that there is a consensus on, for example that the rise in CO2 is anthropogenic, is not because we all agree with eachother, but because the alternative hypothesis is inconsistent with the observations. Of course that doesn't mean there are not still some scientists that disagree, and even the occasional one that manages to get something published in a journal, despite it being incorrect. That is why it is 97% not 100%.
-
Rob Honeycutt at 01:51 AM on 24 July 2014Why we care about the 97% expert consensus on human-caused global warming
troyvit... Don't you think it would be hard to get to a 97% consensus if scientific results were biases along political lines?
I think what you do find is, when scientists express their opinion outside their specific area of expertise, that opinion is going to be far more influenced by their political views over research.
-
troyvit at 01:47 AM on 24 July 2014Why we care about the 97% expert consensus on human-caused global warming
Maybe I'm wrong, but my conservative friends aren't distrustful of science, but rather of scientists, and they have a point. If an intelligent, analytical conservative is more likely to go with his or her crowd, then who is to say that (regardless of political affiliation) scientists wouldn't be victims of their own cultural biases?
Before you say that scientific method is designed to short-circuit that kind of behavior I recommend reading this article:
http://slatestarcodex.com/2014/04/28/the-control-group-is-out-of-control/
which shows just how easy it is to taint the scientific method with preconceptions — even unconsciously.
By the way I believe global warming is human-created.
-
KR at 00:35 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ R. - From the paper:
To select this subset of models for any 15-year period, we calculate the 15-year trend in Niño3.4 index in observations and in CMIP5 models and select only those models with a Niño 3.4 trend within a tolerance window of 0.01K y-1 of the observed Niño 3.4 trend. This approach ensures that we select only models with a phasing of ENSO regime and ocean heat uptake largely in line with observations.
In the 1998-2012 period 4 models met that criteria, for 1997-2011 a different subset, and so on for each 15-year window. As noted above, "The sizes of the dots are proportional to the number of models selected" for each window.
Your false statement is "excluding other models" - all of them were considered for each window, and subsets were selected for each window based on the stated similarity criteria to see how they differed.
ENSO-like variations in the models differ in phase based upon the individual runs. Since the entire purpose of the paper was to see if those models in phase with observational ENSO matched better or worse than those not in phase, the criteria used is entirely reasonable.
-
Charlie A at 00:26 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Perhaps CBDunkerson @38 is taking exception to your use of terms model and model run interchangeably.
I note that the authors also do this. For an example, see the caption to first figure in this blog post where "The sizes of the dots are proportional to the number of models selected. "
It is unclear to me whether the dot size is truly the number of models selected or the number of model runs.
-
Russ R. at 00:09 AM on 24 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
scaddenp @30,
I'll happily answer your question, as soon as someone answers mine.
I asked first (two days ago). You can kindly wait your turn.
CBDunkerson @38
Russ wrote: "The authors took an ensemble of 38 models, and selected a narrow subset (~4) for analysis, excluding the other models."
"Russ, you do get that people are objecting because this is straight up false, right?"Perhaps you might like to try this simple quiz...
- How many models were available for study in the CMIP5 archive?
- How many models were excluded because they lacked outputs of sea surface temperatures for the NINO3.4 region?
- Of the remaining models with NINO3.4 outputs, how many were selected for analysis in each 15-year period as being "in-phase" with ENSO?
Answers:
- 38.
- 20.
- The number of selected "in-phase" models varied for each 15 year period, but only 4 models were selected for the most recent period from 1998-2012.
What part of my statement was "straight up false"?
Moderator Response:[Dikran Marsupial] Please can both sides of this discussion dial back the tone. RussR, answer scaddenp's question and address CBDunkerson's question directly, without sarcasm. If you want scaddenp to answer your question, please restate it politely. I will be monitoring this discussion and will summarily delete any post that violates the comments policy. Note especially:
No profanity or inflammatory tone. Again, constructive discussion is difficult when overheated rhetoric or profanity is flying around.
Please can everybody resist responding to RussR's post until he has first answered these two questions in a reasonable manner.
-
One Planet Only Forever at 23:29 PM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
This is a fabulous discussion.
I would add that economic activity that the entire human population can be allowed to choose to develop to benefit from and continue doing forever will allow constant growth by the creative development of even better 'sustainable activity'.
Any other kind of activity may be incredibly popular and profitable among a portion of the global population for a moment of human future, but damaging activity that cannot be benefited from by everyone, and cannot be continued to be benefited from indefinitely, is a threat to the sustainability of the economy and of humanity. That type of activity is the root cause of most of the viciuous and damaging conflicts that have ever occurred and continue to occur.
This planet is finite and should be habitable by humanity for several hundred million years. Humanity really needs to figure out how to collectively make the best of this good thing, meaning humanity's future depends on competing to develop the best ways of keeping people who don't care about the develoment of a sustainable better future for all life from 'succeeding'.
-
greenhousegaseous at 22:37 PM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
Larry, my twisting of the Pareto Principle was a joke, one I have used in managing projects during a very long career. I start with the traditional 80/20 idea and then focus the team down to the *really* important things to help them find the critical path.
And the 5% I mention isn’t quite the same thing as what Anderson talks about. I was referring rather to the 5% of countries that are doing almost all the damage, in terms of emissions. He’s talking about the societal segment that represent the really serious burners.
Nor did I mean to suggest that the solution implemented should only include the energy gluttons. I completely concur that all need to be actively involved. But the vast majority of countries burn very little FFs per capita. So the main difference is that for most countries, the solution needs to focus on the females: get them educated and empowered to get the birthrates down faster than the UN projects, and get them to financial independence as small business owners ASAP. This goal also confronts the religious and cultural barriers that have driven social economy for centuries.
As Rob repeats, putting a price on carbon via taxation is the critical path step. I add regulation and alternative energy funding. And reaching critical political mass is the prerequisite to both.
The cold truth is that in the taxation/regulatory steps, the poor and developing countries will not play a significant role, in the next 2 or 3 decades. That doesn’t mean they should be ignored.
I agree that the affluent minority is the barrier to seriously meaningful decarbonization. I do not think that class will soon or willingly surrender their privileged lifestyle. So our real challenge is to stage a (hopefully bloodless) revolution, one that restructures consumption globally without imposing some dogmatic sociopolitical agenda.
-
Jim Hunt at 22:23 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
Barry - Over the years a variety of different algorithms (not just bootstrap) have been applied to data from a variety of different satellites. By way of example see:
https://climatedataguide.ucar.edu/climate-data/sea-ice-concentration-data-overview-comparison-table-and-graphs
I don't recall a similar debate over an Arctic sea ice "step change", but changes have certainly happened from time to time. See for example "old" DMI versus "new" DMI extent. -
Ashton at 22:22 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
It was in the piece from Tamino for which I gave the URL in 7 above. It is http://tinyurl.com/qxt7jts. I checked the abstract at Cryosphere (http://www.the-cryosphere.net/8/1289/2014/tc-8-1289-2014.html) and agree with you. As the paper critiqued by Tamino was a pre-release obviously the final words were thought not appropriate. Also I note that the words "raise the possibility that this expansion may be a spurious artifact of an error in the satellite observations" are modified to read "much of this expansion". I should have but didn't, check the final version and apologise for that. However the conclusion from Tamino is that the "increase in Antarctic sea ice cover is robust"
-
Rob Painting at 21:46 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
Ashton - where does your quoted text come from? The last part of the sentence, after the comma, doesn't appear in the abstract.
-
CBDunkerson at 21:35 PM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ wrote: "The authors took an ensemble of 38 models, and selected a narrow subset (~4) for analysis, excluding the other models."
Russ, you do get that people are objecting because this is straight up false, right? You keep plowing ahead as if you've got great points, and you would... if the basic foundations of your arguments weren't fictional.
You might as well be arguing that 'the Risbey paper is bad because it advocates killing puppies'. I understand your outrage at the heinous things you imagine them to have done... but given that these offenses exist in your own mind, its an exercise in self-delusion which is painful to watch. Either the Risbey paper picked ~4 climate models out of 38 or it didn't. Until you can connect with reality enough to see the truth on that point (and various others) you are arguing from a set of 'facts' different from the rest of us, and thus naturally reaching different conclusions.
-
Ashton at 20:04 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
Rob Painting @8 The authors wrote this in their Abstract:
“The results of this analysis raise the possibility that this expansion may be a spurious artifact of an error in the satellite observations, and that the actual Antarctic sea ice cover may not be expanding at all".
Agreed they don't say categorically Antarctic sea ice hasn't expanded but they certainly intimate it may well not have done.
-
Charlie A at 20:02 PM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
The second area of confusion is related to what is the expected performance of the models not in phase with actual real-world Enso.
While the 15 years period 1998-2012has had more La Nina years than El Nino, the ratio hasn't been spectacularly, abnormally lopsided compared to past history. See NOAA ONI table. So, if the random Enso phases of the model runsis the cause of mismatch in GMST trends between models and observations over the last 15 years, then quite a few model runs should have 15 year trends that lie above observations. Correct?
To put it another way, if the only model problem is phasing of Enso, and the current 15 year GMST trends are below all model runs (or perhaps only below 97.5% of all model runs). then I would expect that either 1) that La Nina in the real world over the last 15 years is at or above the 97 percentile point, or 2) that the distribution of Enso in the entire CMIP5 ensemble of model runs is overwhelmingly biased towards El Nino.
#1 is not true. I have not inspected the model oututs, but I doubt that #2 is true.
-
Charlie A at 19:49 PM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
I'll list a few of the key points this blog post made, and then explain more clearly my concern. Please tell me if you disagree with any of these statements made in the blog post
1. " ...because over the long-term, temperature influences from El Niño and La Niña events cancel each other out. However, when we examine how climate model projections have performed over the past 15 years or so, those natural cycles make a big difference."
2. "They looked at each 15-year period since the 1950s, and compared how accurately each model simulation had represented El Niño and La Niña conditions during those 15 years, using the trends in what's known as the Niño3.4 index."
3. "Each individual climate model run has a random representation of these natural ocean cycles, so for every 15-year period, some of those simulations will have accurately represented the actual El Niño conditions just by chance."
-------------------
Everything sounds fine to me up to this point. For each 15 year period, the authors of the paper select that subset of model runs where trends in the Enso 3.4 region best match observations. If they pick the models where enso 3.4 trend best matches observations, I would expect a good match in that area, as shown in fig 5 cell a. However, the authors make a more general claim. They claim the selected "climate models have provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns."
Surely, the authors and the people posting here at SkS mean some other Pacific spatial trend pattern other other than the Enso 3.4 trend for which those specific models were selected.
Correct?
-
Jim Hunt at 19:32 PM on 23 July 2014Is global warming causing extreme weather via jet stream waves?
@Edward - My apologies for my belated response, but given the UK context you may also wish to take a look at another paper by James Screen, which I discuss on my own blog:
Does the Arctic Sea Ice Influence Weather in the South West?
@Ashton - I arrive here fresh from the Arctic Sea Ice Blog, where one of my comments precedes your own! I note you have yet to reply to Neven's comment in response to the question you posed over there. Are you now content that the "remark" you highlight above is not in fact "extraordinary" at all?
@scaddenp - Neven's link doesn't actually cover "all" observations of the Arctic. Particularly if you're interested in Arctic sea ice thickness and/or volume you may wish to also take a look at this collection of my own devising: -
Rob Painting at 18:58 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
Ashton - The paper indicates that the magnitude of the increase may be exaggerated, not that Antarctic sea ice hasn't increased.
-
Ashton at 17:26 PM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
John Hartz Looking at the figure in the article you have mentioned the step change is about 200,000 sqare kilometers. Tamino at Open MInd has critiqued the paper to which you refer and concludes that the increase in Antarctic sea ice is statistically significant (http://tinyurl.com/qxt7jts)
-
scaddenp at 14:40 PM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Charlie A, actually thinking about this more, would it be fair to characterize your position as believing that models are hopelessly wrong (despite the results of this paper) for reasons that have nothing to do with ENSO and that positive ENSO conditions will still result in observed temperatures running below ensemble mean?
If I have got this wrong, then can please state more clearly what your position is, especially in light of this paper?
-
Tom Dayton at 11:44 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ, scaddenp has provided yet another way of phrasing the purpose of the study. It was entirely possible that the model runs best at matching the ENSO index stubbornly would have been nearly as poor at projecting global surface temperature as were the model runs worst at matching the ENSO index. The conclusion would have been that failure to project ENSO timing was not really a major reason for the models' poor projections in 15-year timescales.
-
Rob Honeycutt at 11:00 AM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
Larry, and the trick there is just getting it started in the first place, even at a low level. As I mentioned some number of comments back, I don't think it will take much of a tax to have a fairly significant effect. Then, once it's in place and people see the benefits, it becomes far easier to raise the per ton rate.
The biggest challenge is merely the fact that the FF industry knows they are the ultimate losers in this game. There is no scenario where they come out okay, AFAIK. That means they're going to continue to fight this as long as they can.
-
Larry E at 10:37 AM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
Rob, I'm sure it's the best bet. The trick is to make it stiff enough to get the job done.
-
barry1487 at 10:37 AM on 23 July 2014Climate data from air, land, sea and ice in 2013 reflect trends of a warming planet
I wonder if the supposed step-change applies to Arctic sea ice data also.
-
scaddenp at 09:46 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Charlie A
"This sounds dangerously close "it's the sun" Most Used Climate Myth (upper left sidebar)"
This sounds more like you have completely misunderstood. Would that be deliberate? "its the sun" tries to explain observed warming by changes in the sun. Tom's argument is explaining why models (which have to guess actual forcing) get it wrong if the actual forcing is different. Happens both ways.
The subject of this thread is a paper looking at why observed is low compared to ensemble mean. That they are low is acknowledged in opening of the paper. Does the data support the hypothesis that this is due to state of ENSO? They contend yes and present data to support that.
This has important implications. If the paper is correct, then trends will rapidly increase when ENSO moves positive. Agreed? Or perhaps Charlie you think ENSO is going to stay negative forever?
-
Rob Honeycutt at 09:37 AM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
Larry... Honestly, the one and only way any movement is going to happen is to get a carbon tax implemented. That is the only politically viable solution.
-
Larry E at 08:21 AM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
GHGeous, we are certainly in agreement then on a central point: "I hope I have made it clear ... that IMO we face a much more severe emissions threat than the experts have (to my knowledge) identified ..."
And that, too, is what Anderson is saying (even if his explanation for why his conclusion differs from those of other experts doesn't resonate with you).
Your "Pareto Secret Corollary" seems to be a different fish than Pareto's principle (which is merely a rough first guess, even if apparently accurate in some instances). My belief is that changing the consumption patterns (directly or indirectly) of your 5% of the global population (or Anderson's 1%) is an insufficient incremental target, given the amount of climate change to date, the growing impacts, and that climate scientists are regularly surprised that things are worse than they expected. 5% is only 350 million people, or less than 1/3 of the 1.2 billion population of OECD countries where unsustainable consumption and emissions are ubiquitous. As well, affluent individuals in the developing world are part of the problem as well.
We are down to the move of the last moment, in my view, and focusing on just 5% of us leaves off the hook far too much of the world population that needs to be part of the solution. I believe we need deep change in the very short term, across the affluent section of the world population. Time is scant for addressing the 5%, then the next 5-10%, etc.
How to instill deep, short-term change? That is the dilemma. We should call ourselves Homo lemmingiens, since we seeingly can't break the bonds of our hardwired behaviour despite a recognizable existential crisis. I see society's inabiltiy to consider sacrificing leisure air travel (in degree if not totality) as one strong indicator of this.
-
Charlie A at 06:44 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
@Tom Curtis #19 "...the models only use historical Total Solar Irradiance (TSI) up to 2008, and then repeat solar cycle 23 (April 1996 to June 2008) thereafter. ......This will lead to their warming trends being overestimated by some small amount. "
This sounds dangerously close "it's the sun" Most Used Climate Myth (upper left sidebar).
Figure 2 of this paper show the "small amount" by which forecasted trends have diverged from reality in the sort period of true forecast vs. hindcast. Look closely at the trends from recent observations vs the models. Note it is nearly outside the 2.5 percentile line.
Moderator Response:[PS] This is starting to drift well away from discussing the paper that is the subject of this thread. For general discussions of modelling skill, please put any responses in the "Models are unreliable" thread
-
Charlie A at 06:33 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
@Russ R #1 "..hich parts of planet would you say that the models "accurately predicted"?" and
Russ R #26: " I'd like to know which spatial trend pattern estimates from their selected models were even "good"? "
Obviously, the 4 selected model runs are good in the Enso 3.4 area. The area for which they were selected as being good. Texas sharpshooting at its best.
These are the same models that will be the source for downscaling runs to create the regional predictions that are so popular in the adaptation community, so the poor performance of regional trends outside of the Enso 3.4 area gives and indication of the usefulness of such downscaling.
-
scaddenp at 06:24 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ, this is verging on sloganeering and repetition. You have had it explained to you but at this stage it looks like willful failure to understand.
If you think they what they did was a cherry-pick, will you please explain to us what you think is the appropriate way to test their hypotheses (not yours) in a way that could use the full data set? I would perhaps suggest to the moderators that Russ's posts be deleted if wont either answer the question or withdraw the accusation.
-
Tom Dayton at 05:05 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ: An obviously decent metric of how well the models projected the Pacific spatial trend patterns is the difference in match to observations, of the model runs that worst matched the ENSO index versus the runs that best matched. You can see that in HotWhopper's post by scrolling down to the images that contain the Risbey et al. Figure 5 images.
-
Rob Honeycutt at 04:50 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ... The whole concept was Lew's idea. Did he perform the modeling tests? Probably not. That was left for the researchers who had specific skills in that area.
Read again, Russ: "...natural variability (represented by El Niño/Southern Oscillation) largely in phase with observations..."
Again, your expectation of what models do is absurd. The authors were trying to get the best in-phase runs for a specific region in the eastern Pacific. That's all they're doing. They looked at the 35 runs and selected the ones that were largely in phase with observed ENSO cycles.
How hard is this to comprehend? Really?
-
John Hartz at 04:06 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
In her Carbon Brief blog post, Slow surface warming since 1998 is “not exceptional”, say scientists, Roz Pidcock discusses the findings of Well-estimated global surface warming in climate projections selected for ENSO phase, Risbey et al in conjunction with the findings of a second paper, Changes in global net radiative imbalance 1985-2012, Richard P. Allan et al.
Pidcock's post nicely supplements Dana's OP.
-
Russ R. at 04:04 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Rob Honeycutt,
"I believe you are grossly underestimating the expertise of the researchers and reviewers involved in this paper"
Really? What exactly is Lewandowsky's "expertise" in climate modeling? Is "zero" a gross underestimate?
"You're making an absurd insinuation that a small subset of model runs is going to predict exact regional temperature anomalies."
That's funny... the authors themselves wrote: "We present a more appropriate test of models where only those models with natural variability (represented by El Niño/Southern Oscillation) largely in phase with observations are selected from multi-model ensembles for comparison with observations. These tests show that climate models have provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns."
Nobody's asking for "exact" anything. I'd like to know which spatial trend pattern estimates from their selected models were even "good"? A correct average doesn't mean much if every underlying region is wrong.
If you spend a night at the roulette table, and you get every single bet wrong, can you still claim to possess predictive skill because the average value of your picks was close to the table's average result?
-
keithpickering at 03:29 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Dana,
Thanks for this, which shows again that successful ENSO prediction may be the missing key to short-term climate modelling.
In that regard, allow me to draw your attention to a series of remarkable posts at ContextEarth, where our intrepid blogger has managed to successfully retrodict ENSO for multiple centuries into the past with surprising fidelity. The trick is to use Matheiu functions (which are similar to trig functions in the elliptical co-ordinate system) rather than sine waves. This models the sloshing of water in the Pacific basin, and is tied to at least one lunar cycle.
Rules prohibit me from posting links, but Google should find it. C.E. remains anonymous for now, but he or she is apparently aiming for publication. So keep your eyes open.
Keith
-
keithpickering at 03:02 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ,
It appears to me that you have read everything not behind a paywall, and then didn't understand what you read.
The authors selected CMIP5 models on their ability to replicate the Nino3.4 index. That index is based on the sea surface temperature between 170W and 120W, 5N and 5S. Data shows cooling in that region during 1998-2012, and the 5 best models also show cooling in that region during the same period. Panel b of figure 5, which you omitted because WUWT omitted it (and because apparently you can't be bothered to spend $5 to read the article you criticize) shows that the 5 worst models show warming in that region during the same period.
When the stated aim of the paper is to determine whether there is really something wrong with GCMs or not, comparing a "best" subset to a "worst" subset is not only appropriate, it is often enlightening.
-
Tom Dayton at 02:20 AM on 23 July 2014Climate models accurately predicted global warming when reflecting natural ocean cycles
Russ, your "cherry picking" complaint is groundless. The researchers' goal was to identify a source of model inaccuracy at a 15 year timescale. The researchers did not conclude that those particular models are better than other models at projecting global temperature. As Rob pointed out, the researchers selected only particular runs. The models used for those runs did not accurately predict ENSO events in other runs, nor will those models accurately predict ENSO events in future runs. The researchers did not claim that climate models are better than previously thought. They "merely" identified a still-unsurmounted barrier to models projecting well at short timescales.
-
greenhousegaseous at 02:19 AM on 23 July 2014Deep Decarbonization Pathways Project (DDPP) Presents Interim Report to UN Secretary-General Ban Ki-Moon
LarryE, the DDPP is an attempt to move the discussion closer to the plan and implementation debate, so I commented in this thread.
I hope I have made it clear in my wordy comments above that IMO we face a much more severe emissions threat than the experts have (to my knowledge) identified, and that we need to focus our mitigatory planning and action steps on the 5% who are the source of about 95% of the emissions: the Pareto Secret Corollary, better known in my office as the old 95/5 Rule.
And I hope it is clear that IMO we need to have a functioning economy that, far from being paralyzed by our radical decarbonizing program, is restructured and energized by it.
As for Prof Anderson, I find discussions about the 2% or 4% ceiling or any carbon budget to be diversionary, divisive, and unlikely to help. These discussions are not about the science, but first, the economics of coping with the conclusions of the science, then second, about the politics of implementation.
I have addressed Prof Anderson’s presentation, but not in detail. I have no interest in critiqueing his presentation, since I reached a similar conclusion to Anderson’s central idea about two dozen years ago: a very small percentage of the human population has placed all of us in serious jeopardy - - and are unlikely to do anything to rectify their consumption behavior.
I cannot comment on Anderson’s target of eliminating emissions radically, since he has offered no plan to analyze. Targets are easy to run up the pole, and easy to snipe at; I have no time for either.
It may grab our attention to talk about cutting emissions in the gluttonous countries by 10% a year, but that is meaningless without explaining how, or, more to the point, how to instantly build the necessary political consensus to do so in the face of every established power-elite on the planet.
Rather than find technical (economic and engineering in my case)fault with others’ analysis or proposals, I have been working since the Gore fiasco on finding a more effective way to communicate with a much wider audience than the scientists have managed to reach.
Only quite recently has technology made it possible to reach an audience of millions very fast, *assuming the messaging is effective.* And ours, to be blunt, has not been. My guess is that, so far, all of us on the realistic side of history are reaching perhaps 3 million, half of whom are in countries that will essentially play no part in dealing with the problems.
We must engage and mobilize at least 3 *hundred* million voters and near-future voters to have any chance of survival.
Hence, my concern is not promoting my own hypothesis about the energy-addicted Ape, but in getting the bigger message to all of those folks, in words and numbers and graphics the ordinary voters in the industrial democracies can “get” - - meaning in small doses and across all messaging platforms. Oh, and with a bit of humor, same as John Cook is doing here, now.
So, Larry E, with all due respect, readers here may judge for themselves if I have addressed the entire problem, beginning later this year with the initial free educational tool, and then the initial volume on the carbon “problem”. As of now, there will be 5 or 6 follow-on volumes, each focusing on a tight family of topics and issues, and all timed to synch in with the UN meetings re: the Kyoto Protocol replacement treaty.
I think you may find if you care to that, ultimately, I will in fact address all aspects of “the problem”, in time. Including all those billions of humans Prof Anderson blithely excludes from his discussion. :-)
Prev 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 Next
