I'm sorry, but in my opinion the graph on the right-hand side of this figure is beneath the dignity of any academic or scientist:
If you're writing a report like this, why make it so easy to dismiss you?
PS: More pertinent questions. Don't expect an answer.
One can get away with that kind of stuff in front of a republican congressman, but not in front of a judge.
ReplyDeleteI think Spencer's point may be that both graphs are meaningless without a model. To the uninitiated, a 33% increase in atmospheric CO2 sounds and looks big. An increase of .0001 of the atmosphere sounds and looks small. Both are ways of spinning the facts. The reality is that this increase in CO2 has indeed caused global warming, which Spencer correctly says.
ReplyDeleteCheers
Roy Spencer has repeatedly made the argument in his blog posts that the recent increase in atmospheric CO2 concentration amounts to the addition of less than one single CO2 molecules per 2000 molecules of air, and that, therefore, any discernible variation in weather patterns can't possibly be caused by the recent atmospheric CO2 increase. (This is the same sort of wrong implication that this recent graph of his promotes.) He further implied that since "climate" means nothing more than "average weather", then the CO2 increase can't possibly be responsible for the recent surface warming either. It is very hard to fathom how those invalid arguments can be put forward by the very same individual who repeatedly took on the several greenhouse effect deniers who regularly comment on his own blog. Spencer seems to want to promote acceptance of the reality of the greenhouse effect while insisting that any anthropogenic enhancement of it must necessarily be negligibly small for any practical purpose. When he moves to this second stage of his argumentation, he then happily endorses some of the invalid arguments that he had earlier debunked.
ReplyDeleteIt is embarrassing isn't it - Dr Roy Spencer is not doing science, he is going for emotive arguments and misrepresentations.
ReplyDeleteDo you accept Ljungqvist's reconstruction of past temperatures (Spencer's Figure 3) ? If not, why not, and is there a better reconstruction of the past (say) 2000 years or so ? If you do accept Ljungqvist, how do you explain the variations ?
ReplyDeleteWhy does Spencer use a NH reconstruction rather than a global one?
ReplyDeleteAre there any global reconstructions for the last 2000 years or so ? What do you mean by global reconstruction ? One that uses some sites in the SH ? One that uses an equal number of sites from the NH and SH ? One that uses sites from all seven continents ?
ReplyDeletehttps://www.google.ca/#safe=off&q=global+Surface+Temperature+Reconstructions+for+the+Last+2%2C000+Years
ReplyDeleteA search that gives 2.56 million results doesn't help, if we are to examine your question of why Spencer doesn't use a global reconstruction. You are the one that doesn't like Spencer's choice, so it's up to you to provide one or more alternatives. Please provide your alternative(s) and we can discuss it or them. Otherwise your question is not constructive.
ReplyDeleteSpencer's Figure 3 is also very dishonest.
ReplyDeleteSo are Figures 9 and 10, for not showing the ensemble spread of model results.
It's dishonestly like this that make some people dismiss all UAH temperature calculations as biased. That, and the biased history of their calculations.
Global reconstructions for the last 2000 years or so:
ReplyDelete“A Reconstruction of Regional and Global Temperature for the Past 11,300 Years,” Marcott et al, Science v339 n6124 pp 1198-1201, March 8, 2013
http://www.sciencemag.org/content/339/6124/1198.abstract
"Continental-scale temperature variability during the past two millennia," PAGES 2k Consortium, Nature Geosciences, April 21, 2013
http://www.nature.com/ngeo/journal/v6/n5/abs/ngeo1797.html
Thanks David, I will look at those tomorrow. What is dishonest about Spencer's Figure 3 from Ljungqvist 2010 ? Is Spencer being dishonest or Ljungqvist, or both ?
ReplyDeleteIt's dishonest because Spencer ignored all other reconstructions, cherry picking one that gave him the result a denier like him would want.
ReplyDeleteIt's also dishonest because the figure's caption says "Estimates of Northern Hemisphere average temperature over the last 2,000 years" when in fact Lunquist is for the extratropical NH only.
I would call that caption an outright lie from Spencer.
RM: Are there any global reconstructions for the last 2000 years or so ?
ReplyDeleteA quick search shows 2.5 million results. Yes. I'd say there was at least one he could have chosen.
The Ljungqvist NH reconstruction is consistent with the Mann 2008 NH reconstruction - almost identical: http://www.skepticalscience.com/pics/MobergMannLjungkvist.gif
In that case, why not use the global reconstruction available in Mann 2008? Why limit the result to the NH?
Thanks Layzej, that's interesting. Moberg, Mann and Ljungqvist all show the MWP and the LIA quite clearly in the NH, and both show the MWP comparable with temperatures before the 1997-98 El Nino. I will look at the reconstructions tomorrow, God willing.
ReplyDeleteGood point from David regarding the caption to Spencer's Figure 3. Lyungqvist only looked at 90 N to 30 N, probably because those were the locations he could find.
Richard, here is the graph from Mann et al 1999:
ReplyDeletehttp://www.davidappell.com/hockeysticks.html
Where is the MWP?
"Lyungqvist only looked at 90 N to 30 N, probably because those were the locations he could find."
ReplyDeleteMaybe he should have looked harder, like PAGES 2k did.
It's a rhetorical question with an obvious answer. Why did Spencer use a 30-90N reconstruction rather than a global reconstruction? Maybe ask yourself this: how would a global reconstruction have undermined his narrative?
ReplyDeleteIs he being the least bit honest if his narrative is so easily undermined - simply by including all the data?
David in Cal wrote:
ReplyDelete"I think Spencer's point may be that both graphs are meaningless without a model"
Plainly ridiculous.
Reply to David Appell :-
ReplyDeleteSo why did Mann not find a Medieval Warm Period (or a Little Ice Age) in the NH in 1998-99 (the caption says 1998) but did find both (as Layzej has clearly shown) in 2008, as did Moberg in 2005 and Ljungqvist in 2010 ?
Sorry, not well enough to study your links at the moment.
Mann explains the differences in methodology here: http://www.pnas.org/content/105/36/13252.full
ReplyDeletePierre-Normand -- Here's what Spencer actually wrote:
ReplyDelete"1) Does an increasing CO2 level mean there will be higher global temperatures?
Probably, yes."
He did NOT write, "addition of less than one single CO2 molecules per 2000 molecules of air, and that, therefore, any discernible variation in weather patterns can't possibly be caused by the recent atmospheric CO2 increase."
On the contrary he said that the addition of this small amount of CO2 molecules DOES cause warming, and he explained the mechanism: "the extra CO2 we have added to the atmosphere is believed to have reduced the rate at which the Earth loses infrared radiation to space by about 1 percent, based upon theoretical calculations backed up by laboratory measurements."
Cheers
David -- Regarding Figure 9, no doubt there are any number of ways to combine various model trends and compare them with the actual trend. As far as I know, Spencer used one reasonable approach to combine past model trends.
ReplyDeleteIn any event, I think it's fair to say the actual data shows a definite warming trend, but past IPCC models tended to predict higher warming trends than what we've seen so far.
Cheers
Marcott et al and Pages2K are both paywalled. So are Moberg and Ljungqvist. Loehle and McCulloch also show the MWP and LIA at
ReplyDeletehttp://www.econ.ohio-state.edu/jhm/AGW/Loehle/ - I'm sure that their map of proxy locations would satisfy your global criterion.
Regarding Spencer's Figure 9 in particular, he has published a spaghetti graph of temperature versus models on his blog - for example at http://www.drroyspencer.com/2014/02/95-of-climate-models-agree-the-observations-must-be-wrong/ so it's not hard to find - he probably thought that a simplified version was better for his brochure.
One interesting point: Mann 2008 includes a graph of various proxies vs temp: http://www.ncdc.noaa.gov/paleo/pubs/mann2008/fig3.jpg .
ReplyDeleteThe temp in 2000 is about 0.6C higher than the hottest period in the hottest reconstruction.
But look how much hotter the temp is now than in 2000: http://woodfortrees.org/plot/gistemp/from:1996/trend/plot/gistemp/from:1996
It looks like you'd need to add another 0.4C bringing it to about 1C hotter now than any time in the last 2000 years...
From your earlier graph of Moberg, Mann and Ljungqvist, it looks like the peak of the MWP was about 0.32 to 0.48 C, and the peak before the 1997-98 El Nino was about 0.4 C; so comprable.
ReplyDelete"Marcott et al and Pages2K are both paywalled."
ReplyDeleteGlobal results nevertheless.
"David -- Regarding Figure 9, no doubt there are any number of ways to combine various model trends and compare them with the actual trend. As far as I know, Spencer used one reasonable approach to combine past model trends."
ReplyDeleteI disagree. First, all computer models aren't created equal. Some are good at certain things, others at other things, and just a few are good at all things. Spencer (as did Christy before him) ignored all this by not presenting the ensemble spread. Or at least the standard deviation. To simply graph the mean isn't scientific.
"In any event, I think it's fair to say the actual data shows a definite warming trend, but past IPCC models tended to predict higher warming trends than what we've seen so far."
That assumes the average global surface temperature is being measured accurately. And maybe it isn't:
"Historical Records Miss a Fifth of Global Warming: NASA," 7/21/16
http://www.jpl.nasa.gov/news/news.php?release=2016-194
From the study:
"A new NASA-led study finds that almost one-fifth of the global warming that has occurred in the past 150 years has been missed by historical records due to quirks in how global temperatures were recorded. The study explains why projections of future climate based solely on historical records estimate lower rates of warming than predictions from climate models."
In fact, regarding Spencer's Figure 9, if an undergraduate laboratory student turned in a graph only showing the mean, he'd get a failing grade. And he'd deserve it.
ReplyDeleteThis is not an academic thesis, it's a brochure, intended for a general audience. Spencer has produced a graph of 90 models at http://www.drroyspencer.com/2014/02/95-of-climate-models-agree-the-observations-must-be-wrong/
ReplyDeleteRichard, so it's OK to mislead people because they're not experts?
ReplyDeletePS: I easy found PDFs of both Marcott et al and PAGES 2k online. And both have extensive discussions on RealClimate.
The problem with Figure 9 goes even beyond the lack of a spread in the distribution. It's also the cherry-picking of the start date. If you really want to see how the CMIP5 models compare to the data, you can take a look at Ed Hawkins' comparison here which only goes up to 2015. Gavin Schmidt has a comparison of surface temperatures to CMIP3 & CMIP5 projections that includes an estimate of the mean surface temperature for 2016. Note in this case that the measurement is even above the mean of the CMIP3 model projections.
ReplyDeleteAs for the troposphere measurements, not even Roy Spencer is convinced that the TLT is meaningful anymore. Both UAH and RSS are looking further up in the troposphere. Gavin Schmidt has a nice discussion of the flaws in the Christy model/data comparisons for TMT here. For some time I've been thinking of replotting Gavin's comparison that includes 2016 as well as the RATPAC radiosonde data. The nice thing about Gavin's article is that he even links to the model data so that you can download and plot it yourself.
Reply to Joe T :-
ReplyDeleteSo the observations run mostly in the lower half of the model spread.
Reply to David Appell :-
So you think that plotting the mean of the models is misleading people ?
Marcott et al say :-
"Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history."
so they are not warmer than during ~25% of the Holocene temperature history.
Pages 2K Figure 4 shows the current temperature about the same as circa AD 760.
It would be interesting to see how much that estimate of ~25% has diminished since 2013 when the paper was published. We're now peaking at about 0.25C hotter than the record temperature at that time. It will not be long before we can say unequivocally that temperatures have become hotter than any time in the Holocene.
ReplyDeleteOnce we've eclipsed the Holocene we will have to go back 100,000 years to find a climate that possibly compares.
Of course, the overall trend has been cooling over the last 8000 years or so, so the likelihood of 'record temperatures' will gradually diminish.
ReplyDeleteYes. Except for global warming. We're no longer on the shaft of the hockey stick. We're on the blade.
ReplyDelete"Of course, the overall trend has been cooling over the last 8000 years or so, so the likelihood of 'record temperatures' will gradually diminish."
ReplyDeleteOnly if the factors causing change over the last 8000 years were the same factors as today and will be the same factors in the future.
After all these comments, you still don't understand this. Or pretend not to. Amazing.
"So the observations run mostly in the lower half of the model spread"
ReplyDeleteActually the data agrees very well with the model IF the model had the right phase of the natural variation. Since that phase is chaotic it cannot be predicted beforehand; thus models are run with different initial conditions. We've gone through this before: the consensus opinion in various papers such as those by Fyfe, Kosaka & Xie, Meehl and others is that the brief time in which the data was below the model mean was due to the negative phase of the Interdecadal Pacific Oscillation.
"Pages 2K Figure 4 shows the current temperature about the same as circa AD 760."
There is no reference in the paper to 'current' temperatures. The data is plotted for 30 year intervals and even when they show the Hadcrut4 instrumental data to compare to the proxies, they retain that 30 year averaging. Thus the last data point is the average over 1971-2000. If we compare the latest 30 year average 1986-2015 to the last data point, that temperature is about 0.27C higher. That puts it higher than any other data point on Figure 4b.
"So you think that plotting the mean of the models is misleading people ?"
Yes.
Richard wrote:
ReplyDelete"So you think that plotting the mean of the models is misleading people ?"
Absolutely.
I thought I made that clear.
Richard wrote:
ReplyDelete"...so they are not warmer than during ~25% of the Holocene temperature history...."
So what?
Ricard, are the forcings on today's climate the same as the forcings over most of the Holocene?
Richard wrote:
ReplyDelete"Regarding Spencer's Figure 9 in particular, he has published a spaghetti graph of temperature versus models on his blog - for example at http://www.drroyspencer.com/2014/02/95-of-climate-models-agree-the-observations-must-be-wrong/ so it's not hard to find - he probably thought that a simplified version was better for his brochure."
Then he could have provided a citation or link to it, right?
He didn't. Writing science wasn't what he was getting paid for.
Richard wrote:
ReplyDelete"So why did Mann not find a Medieval Warm Period (or a Little Ice Age) in the NH in 1998-99 (the caption says 1998) but did find both (as Layzej has clearly shown) in 2008, as did Moberg in 2005 and Ljungqvist in 2010 ?"
See Layzej above.
From PAGES 2k:
"There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age...."
http://www.nature.com/ngeo/journal/v6/n5/abs/ngeo1797.html
The funny thing, Richard, is that if you think the MWP and LIA *were* global, then you think the climate is more sensitive to forcings than is currently thought.
ReplyDeleteWhich makes the CO2 problem *much* worse than is thought today.
David in Cal wrote:
ReplyDelete"To the uninitiated, a 33% increase in atmospheric CO2 sounds and looks big. An increase of .0001 of the atmosphere sounds and looks small. Both are ways of spinning the facts."
Wrong. Equivalent ways of presenting the data are not "spinning."
You also got your numbers wrong. CO2's increase is now almost 45%, and it's 400 ppm, or 0.0004 of the atmo.
I didn't get the numbers wrong. The percentage increase in CO2 concentration depends on one's starting point. I was looking at the full Mauna Loa record going back to 1959. It shows a growth from about 310 to 410 ppm, which is just under 33%. See http://www.esrl.noaa.gov/gmd/ccgg/trends/full.html
ReplyDeleteYes, the growth is more like 45% if one starts at an earlier date. A 45% growth would mean a starting CO2 concentration of about 282 ppm. Growth from 282 to 410 ppm would be an increase of 128 ppm, which still rounds off to an increase 0.0001 of the atmosphere.
Cheers
"The percentage increase in CO2 concentration depends on one's starting point. I was looking at the full Mauna Loa record going back to 1959."
ReplyDeleteAs everyone knows, that isn't when the anthropogenic increase started.
So when did the anthropogenic increase in CO2 start ?
ReplyDeleteIn reply to your other comments :-
(7:21 pm) There are many factors affecting global temperature, not just CO2, but also TSI, MEI, AMO etc.
(7:19 pm) So Mann did not find a MWP and LIA in 1998-99, he did find one in 2008 (in the NH, where most people live), and he didn't find one in 2013.
(7:08 pm) Why don't you ask Spencer why he did not write the brochure as you think he should have done, instead of asking me ? I have always found him to be very approachable, so I'm sure that you will receive an explanation from him.
(7:07 pm) Again, there are many factors affecting global temperature, which is why there are warming and cooling periods on decade and century time scales.
Reply to Joe T :-
Hawkins shows temperatures clearly in the bottom half of the model spread.
RM: So when did the anthropogenic increase in CO2 start ?
ReplyDeleteYou'll find that Skeptical Science is a great resource for these questions and I encourage you to bookmark it: Annual emissions of CO2 by human use of fossil fuels rose from 3 million tonnes of Carbon (11 million tonnes of CO2) in 1751 to 54 million tonnes of Carbon (198 million tonnes of CO2) in 1850. After that fossil fuel use rose sharply so that by 2008, annual emissions (including from cement manufacture) had risen to 8749 million tonnes of Carbon (32 billion tonnes of CO2). - http://www.skepticalscience.com/anthrocarbon-brief.html
RM: Hawkins shows temperatures clearly in the bottom half of the model spread.
This animation illustrates why it does not mean what you think it means: Models show that actual temperatures should be above or below the mean for decades at a time. This is exactly what the models predict.
RM: Why don't you ask Spencer why he did not write the brochure as you think he should have done.
The answer is obvious. It fits the narrative that he is trying to spin. David is just pointing out how hollow that narrative is.
So if fossil fuel use rose sharply since 1850, then we know that since then we have had :-
ReplyDeletecooling 1850-1861 11 years at -1.25 C per century
warming 1861-1877 16 years at +1.16 C per century
cooling 1877-1910 33 years at -0.66 C per century
warming 1910-1943 33 years at +1.44 C per century
cooling 1943-1955 12 years at -0.97 C per century
stasis 1955-1975 20 years at -0.06 C per century
warming 1975-2015 40 years at +1.73 C per century
So there are clearly other causes of warming and cooling since 1850.
Overall, the rate of increase has been 0.50 C per century.
What we don't know (I haven't even seen an estimate) is how much of that overall rise in temperature is due to CO2, and how much is due to TSI, MEI, AMO, etc.
So Spencer is 'trying to spin' a narrative when he says :-
"the extra CO2 we have added to the atmosphere is believed to have reduced the rate at which the Earth loses infrared radiation to space by about 1 percent, based upon theoretical calculations backed up by laboratory measurements."
Spencer concludes that :-
"Uncertainties in the adjustments to our global temperature datasets, the small
amount of warming those datasets have measured compared to what climate
models expect, and uncertainties over the possible role of Mother Nature in recent warming, all combine to make climate change beliefs as much faith-based as
science-based."
We will have to wait until the current El Nino (and possible La Nina) conclude before we can start to answer some of these questions.
"So Mann did not find a MWP and LIA in 1998-99, he did find one in 2008 (in the NH, where most people live), and he didn't find one in 2013."
ReplyDeleteDid you even read these papers, because it sure looks like you didn't? First of all, the 1998 paper only went back to 1400. Yeah, no MWP. But the paper did clearly show the long term cooling trend as one would expect from the orbital forcing. The 1999 paper goes back to 1000 and didn't show a clear MWP because as he writes in that paper, "We here apply the methodology detailed by MBH98 to the sparser proxy data network available prior to AD 1400." Mann, unlike Spencer actually believes in showing uncertainties and if you ever read the paper you would find that the 2-sigma uncertainty around 10000 is +/- 0.5 C, well within the range of subsequent reconstructions of the MCA, as it is called. That's the thing about science, it builds on what was done before. With regard to your reference to 2013, I have no idea what you're talking about. If it's the PAGES 2K paper, then Mann is not a co-author on that paper. And that paper was a reconstruction based on data from all seven continents, not just the NH.
"Hawkins shows temperatures clearly in the bottom half of the model spread."
Now you're just repeating yourself. Perhaps the point you're really making is that Spencer's claim that "models are warming about twice as fast as the
real world" is just garbage. If so, then I agree.
RM: What we don't know (I haven't even seen an estimate) is how much of that overall rise in temperature is due to CO2
ReplyDeleteYou should say, "what I don't know". That way you don't presume to speak for people who have taken the time to look up the answer. (spoiler: likely more than all of it)
Reply to Joe T :-
ReplyDeleteYes, I probably meant Pages 2K, sorry.
Reply to Layzej :-
ReplyDeleteObviously, Foster and Rahmstorf only go back to 1950, and they only consider ENSO (which has only a short term effect) solar variability and volcanic aerosols (again a short term effect)
They do not consider the AMO, PDO or IPO, for example. Also, they make no attempt to explain the cooling period from 1950-1975 of -0.14 C per century.
The piece you want to look at is this: https://i.guim.co.uk/img/media/5260dcfa4a5e7762868416edb3e10fc706eff6fa/0_0_677_461/master/677.jpg?w=620&q=55&auto=format&usm=12&fit=max&s=27a3ac280c28eeadec0735fca8864978
ReplyDeleteYes, that's what I was referring to.
ReplyDeleteThat's not Foster and Rahmstorf.
ReplyDeleteSorry that's Nucitelli.
ReplyDeleteThe studies are Tett et al. 2000, Meehl et al. 2004, Stone et al. 2007, Lean and Rind 2008, Huber and Knutti 2011, Gillett et al. 2012, Wigley and Santer 2012, Jones et al. 2013, IPCC AR5, and Ribes et al. 2016. When you say "We don't know", that's only true for a very small value of "we".
ReplyDeleteBottom line: ~all (possibly more than all) of the ~0.9C of warming since 1950 was anthropogenic.
Now we need to ask the same question about 1850-2015 and ask how much warming was caused by the AMO, PDO, NAO, IPO etc.
ReplyDeleteWhy?
ReplyDelete"Now we need to ask the same question about 1850-2015 and ask how much warming was caused by the AMO, PDO, NAO, IPO etc."
ReplyDeleteNo warming was caused by them. They are natural cycles that do not add heat to the system, they merely recirculate it and move it around.
So what caused the massive drop in temperature in 1802-1811, as shown in the Berkeley Earth Global land temperature data series ?
ReplyDeleteRead their paper:
ReplyDeletehttp://static.berkeleyearth.org/papers/Results-Paper-Berkeley-Earth.pdf
"...several of the cool periods in the early 1800s have been associated with large volcanic eruptions." More details in the paper.
Thanks David, I will read the paper.
ReplyDeleteYes, there was a large volcanic eruption (Volcanic Explosivity Index 6-7) in 1808-1809 which probably caused the massive drop in temperature which reached a trough in 1811. The paper also acknowledges a small contribution from the AMO over multi-decadal time scales.
ReplyDeleteFollowing up on my post at 1:49 PM above, I compared the Christy/Spencer models of TMT to RSS v4 and UAH v6 beta5 as Gavin Schmidt did in the link above. Gavin's realclimate post is the source of the models. I followed Gavin's format of keeping the baseline as the mean of the 10 year period 1979-1988. I didn't use the NOAA Star data or the earlier versions of RSS/UAH. However, I did use the RATPAC-A radiosonde data as well.
ReplyDeleteThe problem with responding to blog posts and brochures and not published papers is that I have no clue as to what the models are supposed to represent. Are they a synthetic diagnostic based on the CMIP5 calculations that are meant to simulate the weighted path length integration of the microwave emission over the middle troposphere? I have no idea. So what I did instead is simply use the RATPAC data at 500 mbar, which is roughly where the middle troposphere is. Consider this a zeroth order approximation. If it's a weighted average that's easy enough to do, but I doubt it would make a huge difference.
You can find my plot here. The RATPAC data follows RSS fairly well until 2010 or so. I still wonder if there is a problem with the hot load calibration as Carl Mears writes about here.
Many thanks for that, Joe T. Again, the observations are mostly in the lower half of (or even below) the model cluster.
ReplyDeleteHi JoeT (or David),
ReplyDeleteI'm not sure whether you have this info in your back pocket, but just in case:
Is it possible to get the CMIC5 model mean data prior to 2006? I've been able to get the mean from 2006 on using http://climexp.knmi.nl/plot_atlas_form.py. Dump1 contains a file with *onemean* in the name and covers 2006 and beyond. Dump0 doesn't have a similar file...
Thanks!
Jeremy
Hi Jeremy,
ReplyDeleteI don't the answer to your question.
(I find it difficult to get CMIP data of any kind, even with the KNMI Explorer.
-- David
Oh well. Thanks!
ReplyDelete