Guest Post by Bob Tisdale
We discussed Steinman et al. (2015) and Michael Mann’s post about it at RealClimate in the article On Steinman et al. (2015) – Michael Mann and Company Redefine Multidecadal Variability And Wind Up Illustrating Climate Model Failings. This brief post adds to that discussion.
THE PAUSE, HIATUS, SLOWDOWN (WHATEVER) IN GLOBAL WARMING IS MORE PREVALENT IN THE SOUTHERN HEMISPHERE, YET MANN AND STEINMAN ET AL. FOCUSED ON THE NORTHERN HEMISPHERE
The opening paragraph in Michael Mann’s post at RealClimate reads:
No, climate change is not experiencing a hiatus. No, there is not currently a “pause” in global warming.
The initial topic of discussion is GLOBAL warming…and Mann’s perception that there is no pause in the surface temperatures GLOBALLY.
Yet Mann in his blog post and Steinman et al. have redirected the discussion from global warming to Northern Hemisphere warming. That is, Steinman et al. (2015) was not an examination of the modeled and observed surface temperatures globally. Their paper only looked at the surface temperatures of the Northern Hemisphere, and the sea surface temperatures of the North Atlantic and North Pacific. Mann even notes this a few paragraphs later, where he opens the paragraph with:
We focused on the Northern Hemisphere…
But it’s well known that the hiatus, the pause, the slowdown, etc., in surface warming is more prevalent in the Southern Hemisphere than in the Northern Hemisphere. If you aren’t aware of that fact, I’ll show you.
The year 1998 is commonly used for the start of the global warming slowdown, and Kevin Trenberth used 2001 in his article Has Global Warming Stalled? for the Royal Meteorological Society. (Also see my post Open Letter to the Royal Meteorological Society Regarding Dr. Trenberth’s Article “Has Global Warming Stalled?”.) So we’ll present the data with both start years. For the data, we’ll present the widely referenced, spatially complete GISS Land-Ocean Temperature Index (LOTI) data.
Figure 1 compares the Northern and Southern Hemisphere surface temperature anomalies during the hiatus. In the top cell, the data start in 1998, and in the bottom cell, the data start in 2001. As noted earlier, the slowdown in surface warming is more prevalent in the Southern Hemisphere.
Figure 1
And for those interested, Figures 2 and 3 present model-data comparisons for the Northern (Figure 2) and Southern (Figure 3) Hemispheres for the two slowdown periods. The models are represented by the multi-model mean of all of the climate models stored in the CMIP5 archive, with historic forcings through 2005 and RCP8.5 scenario forcings thereafter. The data and the model outputs are available through the KNMI Climate Explorer. We present the multi-model mean because it best represents the consensus, the groupthink, on how surface temperatures should have warmed if they were warmed by manmade greenhouse gases and the other forcings. In other words, the model mean represents the forced component of the models. For additional information on the use of the model mean, see the post here. (Also see the discussion of Estimates of the forced component under the heading of Materials and Methods in the Supplementary Material furnished with Steinman et al.)
Figure 2
# # #
Figure 3
It appears that Michael Mann may have biased his opinions about the slowdown in global surface warming by looking only at data for the Northern Hemisphere, which shows higher warming rates than the Southern Hemisphere. One only has to look at trend maps of the global warming slowdown periods in Figure 4 to see that there is less warming in the Southern Hemisphere. (The trend maps are available from the GISS map-making webpage.)
Figure 4
CLOSING
The Steinman et al. (2015) analyses do not explain the slowdown and stoppage of surface warming in the Southern Hemisphere…and, as noted in the earlier post, they had to redefine multidecadal temperature variability to try to explain it in the Northern Hemisphere.
SOURCE
The GISS LOTI data and the climate model outputs are available from the KNMI Climate Explorer.
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He’s the abominable faux Mann.
Very interesting comparison: A brand new paper about pacific natural variability http://link.springer.com/article/10.1007%2Fs00382-015-2525-1 ( attention!! see 2nd author…) defines a tripole index for the measurement of the pacific oscillation. In the supps is included an Exel-file with the data of this indes up to 02/14. Please compare the MM – graph here: http://images.huffingtonpost.com/2015-02-12-Sci15FigHuffPost.png ( pacific in green) with the data from the latest paper ( with the real world data): http://kauls.selfhost.bz:9001/uploads/tpi.png . Where is the sharp decline after 2000 of MM’s paper?
We really should start calling it Polar Warming because every heat map ever constructed shows that the most significant warming *always* occurs at the poles where the instrument coverage is least and human activity associated with infilling, homogenizing, folding, spindling and mutilating of the data is most.
The graphs are a problem, each one has a different Y axis scale making slope comparison difficult. You might want to correct.
I found years ago when plotting slopes for gieger counters, that plotting the slope on semi-log paper made the slopes appear equal if, in fact, they were.
It should be noted from Figure 4 , that the ONLY place that there seems to be any so-called “warming” is where it probably isn’t measured very well. The section over the north of Russia.
And lets not forget that the Russian have mentioned that GISS have dumped a lot of the data from that region. !!
And its not a hiatus or a pause.
Its a CESSATION of warming, mainly because they can no longer make adjustments that cool the past because the past now includes a lot of the satellite record..
But they will keep trying. Looking for out of the way places where they create a warming trend.
Very embarrassing watching bald bearded men lying for their careers.
Well yes but it doesn’t have to be over for Mann.
If the three stooges are ever brought back, I think Mann should audition for the part of Curly. In this way he redeems himself by applying his natural skills at playing a fool. If that doesn’t work out, there is always the circus, they need clowns.
If they really care about warming, they should be launching more measurement satellites.
Its very obvious that these satellites have a strong stabilising effect on the global temperature.
I think we can all be pretty sure, that without satellites the current global temperature would be up near the model mean, as surface stations got adjusted for “regional expectations”
That’s because the satellites block more sunlight reducing the effect of CO2 in the atmosphere, but just wait at the rate we are putting CO2 into the atmosphere it will soon (somewhere between 1 year and 100,000 years) swamp the effect of all those satellites blocking the sun.
I’m surprised that Gavin hasn’t started compensating for the blocking effects of those satellites !
Although, I suspect he has, in his own little way. 😉
FTA: “But it’s well known that the hiatus, the pause, the slowdown, etc., in surface warming is more prevalent in the Southern Hemisphere than in the Northern Hemisphere.”
Maybe according to GISS, but GISS is largely manufactured, with questionably infilled data for areas without coverage. According to HADCRUT4, NH temperatures are, in fact, declining. SH temperatures haveplateaued.
Bart for what is actually going on check my earlier comment
http://wattsupwiththat.com/2015/03/05/another-couple-of-notes-about-michael-manns-faux-pause-post-and-steinman-et-al-2015/#comment-1875770
@rd50 n general
When things get soooo complex and confusing, it is up to ingenuity and perhaps intuition, to find concrete facts that stand a pounding from data, science and timescale (v. long one). One occuring to me is that there have been times on earth when the CO2 levels have been sooo much higher and yet the earth did not cook and stay cooking, so feedback is really not a plausable fact. There have also been recent times when the CO2 was rising and the temperature fell, even disturbing some to predict an ice age (just a few decades ago). There is so little CO2 in the air compared to water vapour, that to suggest any significant CO2 influence does not add up, even a little bit.
I must admit that I have not the capacity to remember each and every interesting correlation or otherwise and the logic/science/physics that is behind it. What I do do, however, is assess, in my own way, to my own satisfaction, the effects of all that get mentioned from time to time and form a reasoned arguable guesstimate how they might fit, or not, in the big picture. Whilst I may forget many facts and specific reasonsings, there is in my head a running tally so to speak, that relates to the argument and specifically if CO2 is causing warming. I have done this for a good while now and have the firm belief that Co2 has such a small role on the big global stage that it is dismissable, totally – it just reflects on how much heat there is globally – no effects (sorry bout choice of words but we need a laugh now and then and whilst Mann and other are a joke of nature, the effect they are having and the apalling corruption of science and the integrity of scientific method, in my view, is sad beyond belief – one of the most important and hard won triumphs in human awareness and thought is being trashed, twisted and torn, for money, job security and ego.)
Whatever CO2 does, it does it in the ‘noise’ regions of other, more significant and plausable causes and effects, in terms of holding on to a bit of heat for the globe. In terms of its own existence and quantities thereof, I am convinced it increases as and because the temperature does.
I would agree with you, I also think the CO2 effect is very small and thanks for the reply.
Depending on “when” you look for a correlation between CO2 and temperature you may or may not find a good fit.
My major problem about CO2 is with the validity of CO2 measurements before Mauna Loa. I trust these measurements completely and I think this will be confirmed from the OCO-2 satellite measurements shortly.
So I am not willing to go back for correlation between CO2 and temperature prior to 1959.
Not that I have great confidence in the GISS data, I would prefer RSS data for temperature but this started only in 1979.
On the practical side, we are told that this increase in CO2 is “anthropogenic” due to fossil fuels burning and so we must stop this immediately because temperature increase will bring dire consequences.
First there is no proof that the CO2 increase is all due to fossil fuel burning but second and more importantly this “anthropogenic” increase in CO2 started very recently. So, what is the point of going back centuries?
I am not buying. If we caused it, we did it recently (and even if this increase is due to another source) then there should be a correlation between CO2 increases and temperature increases. Otherwise stop telling us to replace fossil fuels. I can find such a correlation starting in 1959 as noted in my above post, but then as time progresses and CO2 continues to increase the correlation is lost.
Since the correlation is lost, the difference between the temperature predicted by the models and the actual temperature is now becoming obvious, but not enough just yet. So, I just have to wait and see. But at one point, enough will be enough waiting.
Neglecting cosmic background radiation (~4 K, a small effect), it is fairly easy to show that the equilibrium radiant temperature of the Earth (Te) is found as Te^4 = (I/2s)(a/e) where I is the solar constant at the orbit of the Earth (watts/m2), s is the Stefan-Boltzmann constant, a is the spectrally-integrated radiant absorptivity (dimensionless), and e is the spectrally-integrated emissivity (dimensionless). Of the terms on the right-hand side, the first one is nearly a constant. The second term can, in principle, assume a very wide range of values. For example, the absorptivity is essentially the complement of albedo, and we do not know the albedo to better than 10%. Thus a 10% variation in the absorptivity becomes a 2.41% variation in the nominal temperature. If the nominal temperature is near 300 K, this becomes a temperature variation of 7.23 K. This little back of the envelope exercise shows that everything at stake in the global warming controversy is lost in our ignorance of the basic radiant transfer parameters of the Earth, and which may also contain the explanation for the drastic swings in temperature that cause and reverse the ice ages.
It’s time to label this whole scurrilous promotion for what it is: not global warming, not climate change, not climate disruption, but Climate Duplicity, and to label the followers of such proponents as Climate Dupes, for that is what they are. The failure of our highest institutions to stand against the tsunamis of money and power that have flooded this arena demonstrate that we must begin the arduous task of reforming and protecting against such resource-squandering duplicities. How best to accomplish this?
Steadfast opposition at every level. Exposure of the lies. Documenting and publicizing the money trails and enormous wastes, with absolutely nothing to show for it except more promulgation of the same. It will not be easy…
Terry Burch
… “Climate Scam” ?
UHI concentrations and urban areas are far greater in extent and number in the Northern Hemisphere than in the Southern Hemisphere. Urban areas are from where they get the majority of their temperature records. Any outlying rural areas are also ‘homogenised’ up to the nearby urban areas. Thus the increasing trend in the NH is easily shown as bigger than at sea in the SH. The NH can be made to support the Warmistas’ meme, the SH is not so maleable,
… and they tell us that CO2 is a well mixed gas !?
It is unless we want to start bitching about 5% difference in ppm concentrations between here and there. We already have this also from recent preliminary maps from the OCO-2 satellite. More data coming soon. I am hoping that we will be able to detect some interesting but circumscribed little hot spots to learn about possible “non anthropogenic” sources, this could be interesting. I am not sure that there is the possibility of detecting, for example the increase in CO2 during morning and night rush hour traffic in a large city or over a very large corn field on a sunny day at noon.
I’ll be happy to see warming trends and abundant CO2 continue. I only dread the cooling that is the alternative.
I am also happy to see the abundant CO2 continuing. However, I don’t want the temperature to increase not because I fear it. Simply, if the temperature starts increasing again we will get that since CO2 is increasing it is responsible for the renewal of the temperature increase and therefore we need to eliminate fossil fuels. This is the IPCC call. More CO2=Temperature increase.
I want CO2 increase but no temperature increase so that it becomes obvious that the differences in temperature between the predictive models and actual temperature will continue to increase.
Only then can we tell the IPCC that their CO2 driving force is wrong.
Until someone reliably quantifies global mixing ratios, which is more important than temperature in climate ( for instance warming in the arctic winter means next to nothing compared to slight cooling in the tropics) this is all like a dog chasing its own tail.
Specific Heat is a far more accurate measurement than temperature.
if you want to measure global temperature trends the southern hemisphere should count more than the northern cause if has the most oceans and hence the most closely coupled thermal mass.
Mann,s conclusion:
“No, climate change is not experiencing a hiatus. No, there is not currently a “pause” in global warming.
Because we have found the global warming still happening as it supposes to, the AGW and the hotspot and all that, as actually it should be, quasi exactly at the right spot but with a very slight and lilly lilly small difference.
It happens to be under the Pacific surface instead of above the surface, a lilly lilly tiny small difference.
And as it could not be measured or directly observed we can make it as big and large as wanted.”
Voila the Mann’s glob’s warming evidence.
cheers
Well that’s how global temperatures are determined, you pick selected areas or area to capture temperature readings, then infill for areas either unmeasured or whose measurements are deemed unfit.
In this case Michael Mann used the Northern Hemisphere to infill for the southern hemisphere. I am surprised anyone is surprised at this, this is standard operating procedure in climate science.
As Elaine would say in Seinfeld, “It’s all about the infilling.”
Couple of suggestions. First, use monthly, not yearly intervals for your temperature curves. Secondly, the current hiatus is not the first one. There was a hiatus in the eighties and nineties whose presence was first shown in my book in 2010 (figure 15 of “What Warming?”). During this hiatus, global mean temperature did not change from 1979 to 1997, an 18 year stretch. But you don’t know about it because it is covered up by fake warming, result of a conspiracy among GISS, HadCRUT, and NCDC. They show this fake warming as coming from “NASA” – apparently from GISS that Hansen used to direct. They continue it into the 21st century. This is the only way they could crown 2014 as the warmest year ever. You should start your graph with 1979, not with 1998, in order to to show both hiatuses simultaneously. Second, use only satellite temperatures, not those polluted data from ground-based data sets. They synchronized their data by common computer processing and that left its footprints in their publicly available temperature curves. These consist of sharp upward spikes at the beginnings of years. . They had no idea this was happening. This “feature” is an addition to the false warming they are peddling. Satellites are free of this junk and show the El Nino peaks also more clearly and accurately. Speaking of El Nino, one of their own computer processing spikes sits right on top of their squashed-down 1998 super El Nino peak.
I do not see any problem with the authors of the study concentrating on just the Northern Hemisphere. As I understand it the point of the study was to show internal variability explains some of the hiatus in the global average temperature measurements. The study then showed where the internal variability in the Northern Hemisphere could be coming from.
Criticising the study for not including the Southern Hemisphere is a straw man as the authors never said they were going to explain all the hiatus in their study.