“The weather forecast looks sunny and particularly hot from Sunday to Friday, with afternoon temperatures above 30°C every day, and likely exceeding 35°C by the middle of the week. One consequence is that the poster sessions (Tuesday and Thursday) have been moved to the morning as they will be held outside under a marquee.”
I have never received a notification like this before a conference. And it was then followed up by a warning from the Guardian: ‘Hell is coming’: week-long heatwave begins across Europe.
The heatwave took place and was an appropriate frame for the International meeting on statistical climatology (IMSC), which took place in Toulouse, France (June 24-28). France set a new record-high temperature 45.9°C on June 28th, beating the previous record 44.1°C from 2003 by a wide margin (1.8°C).
One of the topics of this meeting was indeed heatwaves and one buzzword was “event attribution”. It is still difficult to say whether a single event is more likely as a result of climate change because of model inaccuracies when it comes to local and regional details.
Weather and climate events tend to be limited geographically and involve very local processes. Climate models, however, tend to be designed to reproduce more large-scale features, and their output is not exactly the same as observed quantity. Hence, there is often a need for downscaling global climate model results in order to explain such events.
A popular strategy for studying attribution of events is to run two sets of simulations: ‘factual’ (with greenhouse gas forcing) and ‘counterfactual’ (without greenhouse gas forcings) runs for the past, and then compare the results. Another question is how to “frame” the event, as different definitions of an event can give different indicators.
Individual heatwaves are still difficult to attribute to global warming because soil moisture may be affected by irrigation wheras land surface changes and pollution (aerosols) can shift the temperature. These factors are tricky when it comes to modeling and thus have an effect on the precision of the analysis.
Nevertheless, there is little doubt that the emerging pattern of more extremes that we see is a result of the ongoing global warming. Indeed, the results presented at the IMSC provide further support for the link between climate change and extremes (see previous post absence of evidence).
I braved the heat inside the marquee to have a look at the IMSC posters. Several of them presented work on seasonal and decadal forecasting, so both seasonal and decadal prediction still seem to be hot topics within the research community.
A major hurdle facing decadal predictions is to design climate models and give them good enough information so that they are able to predict how temperature and circulation evolve (see past post on decadal predictions). It is hard enough to predict the global mean temperature (link), but regional scales are even more challenging. One question addressed by the posters was whether advanced statistical methods improve the skill when applied to model output.
A wide range of topics was discussed during the IMSC. For instance, how the rate of new record-breaking events (link) can reveal trends in extreme statistics. There was one talk about ocean wave heights and how wave heights are likely to increase as sea-ice retreats. I also learned how severe thunderstorms in the US may be affected by ENSO and climate change.
Another interesting observation was that so-called “emergent constraints” (and the Cox et al, (2018) paper) are still debated, in addition to methods for separating internal variability from forced climate change. And there is ongoing work on the reconstruction of temperature over the whole globe, making use of all available information and the best statistical methods.
It is probably not so surprising that the data sample from the ARGO floats shows an ongoing warming trend, however, by filling in the spaces with temperature estimates between the floats, the picture becomes less noisy. It seems that a better geographical representation removes a bias that gives an underestimated warming trend.
While most talks were based on statistics, there was one that was mostly physics-based on the transition between weather regimes. Other topics included bias-adjustment (multi-variate), studies of compound events (straining the emergency service), the connection between drought and crop yields, how extreme weather affects health, snow avalanches, precipitation from tropical cyclones, uncertainties, downscaling based on texture analysis, and weather generators. To cover all of these would take more space than I think is appropriate for a blog like this.
One important issue was about data sharing which merits wider attention. The lack of open and free data is still a problem, especially if we want to tackle the World Climate Research Programme’s grand challenges. European and US data are freely available and the Israeli experience indicate that open access is beneficial.
#45 libertador,
I think if you read the entire discussion from the beginning, I am not “describing what attribution science does” in any way inconsistent with what you are saying.
But my statement is correct, because it does apply to a specific event, not to some category.
Again, it’s about clarity of language, and cause and effect.
No 57 exactly…
Re. “Attempting attribution of an event is silly.”
Then pretty much all of science is silly, I guess.
If I put a magnet under a roulette wheel’s 00 and then run statistics on the wheel’s long run distribution, can I make any attribution statement about how much the magnet there changes the resulting distribution?
According to some here, apparently not.
jgnfld,
An event is not the same as a distribution.
“Make an attribution statement” is not the same as “attribution of an event”.
And a cause is not the same as an effect.
1. The magnet is a cause.
2. The nature of every individual event (pocket number, =effect) is caused by the magnet.
3. The distribution is a description of the aggregate of the events.
If we know that the ball is made of a material affected by magnets, and we know that the magnet has been placed, then we don’t need the distribution to attribute individual ball locations to the presence of the magnet.
Unless, perhaps, you are in denial about basic physics, like the Denialists?
60 jgnfld says:
“If I put a magnet under a roulette wheel’s 00 and then run statistics on the wheel’s long run distribution, can I make any attribution statement about how much the magnet there changes the resulting distribution?”
Yes you can. And if the power of the magnet steadily increases while the perceived effect decreases or remains the same, over a period of 40 years (1940-1979), then, as should be clear, the effect cannot be attributed to the presumed cause.
Weaktor,
I believe the words “ceteris paribus” might be missing from your #62, and since we know the ceteris were in fact not paribus, the rest is utterly irrelevant, like most of your drivel.
V 62: And if the power of the magnet steadily increases while the perceived effect decreases or remains the same, over a period of 40 years (1940-1979), then, as should be clear, the effect cannot be attributed to the presumed cause.
BPL: Victor still doesn’t believe an effect (temperature) can have multiple causes (CO2, aerosols).
jgnfld re #62 from Victor,
You see my point? They just ignore the physics.
If you and others are doing it… leaving what we do know out of the discussion, and being sloppy with language… it is “enabling” them.
@61
Disagree with your definitions. The notion in attribution theory is statistically detecting and identifying the nature of any signal which is above random or “natural” variation.
Here the frequency of observing 00’s changes from 1 in 38 to some higher value. The change can be attributed to a cause–the magnet. If the magnet is powerful enough, 100% of the resulting string of all 00’s can be attributed to the magnet and 0% to random variation. Less powerful magnets allow some random variation to occur and therefore less will be attributed to the magnet.
Jgnfld,
Zebra gets it. Changing the WHOLE FRIGGING SYSTEM changes everything. You can’t say that an event would have happened anyway, but of a different magnitude, when the wheel has been changed. “Attribution” makes sense in the “this level of deviation will happen that percentage of times” way, but to attribute a single event is stupid. Remember, physics says that you CAN drop a pencil through a solid oak table. Attribute THAT.
To clarify,
Attributing TWO incidents is noticeable (two pencils dropping through two oak tables in identical frames). THREE is serious data. Repetition and replication depend on the laws of many and varied randomicities.
And there is no “control planet”. No way to differentiate our path from what would have been (at least directly). There is no Planet “A”.
Victor @62:
The answer to your seeming paradox is that AGW effects are not necessarily linear over all time since it started, because AGW is not the *only* thing happening at all times since it started. The mid century ‘pause’ follows and coincides with with massive anthropogenic injection of aerosol pollutants into the atmosphere, primarily from burning coal, which had direct and indirect cooling effects. Guess what happened in the late 1960s and in the 1970s? Major efforts to reduce air pollution in the developed world, particularly sulfates. By the end of the 70s the warming ‘signal’ emerged from the reduced ‘noise’.
I have a feeling you’ve been told all this already. It seems to be your pattern: you try a ‘gotcha’, it fails in the face of science, then you wait awhile and repeat it again. Please take your insufferable repetitive ignorance, cherry picking, and sophistry elsewhere.
Zebra @61 and elsewhere appears to suggest that attributing specific weather events to climate change is unwise because it feeds the denialists, because its hard to be 100% certain that an event is 100% caused by climate change (or global warming Zebra prefers this term) and this gives the denialists an opportunity to spread doubt. It’s a fair comment about the denialists, but its not a compelling reason not to do attribution studies . You don’t back off an obvious scientific question just because of moronically inclined denialists.
Zebra thinks instead that we should just focus on more energy in the system causing changed weather, perhaps because this is hard to rebut. Ok this is factually true, but people will want to know more than this. At the very least some weather events are also made more frequent or intense by climate change because we have empirical data. Yes the denialists will attack this.
Zebra also seems to now be questioning whether its possible to even attribute a specific weather event to climate change. But its trivially obvious that some weather events are 100% due to climate change. For example a climate like snowball earth would not have supported 45 degree c heatwaves (an extreme case to make the point). Of course working out whether certain recent heatwaves would only have occurred with climate change is difficult, and scientists have only been able to say that its highly likely an event would not have happened without climate change, or that it is highly likely it wouldn’t have been as severe. So hmmm attribution studies look ok to me, although I get Zebras frustrations over the issue.
@zebra
Not sure what your issue is, but don’t agree with your distinctions as stated.
When I make a probability statement from a presumed model of some phenomenon I am attributing to each and every _elementary_ event the causes the model encapsulates. This is basic science across all fields of study. By using an observable magnet I was trying to make things easy, but perhaps this was confusing?
According to the probability I studied in grad school anyway, an aggregate (union) of elementary events is itself an event though not necessarily an elementary event. That is, an (empirical) distribution of events is an event every bit as much as one observation is. Eg., re. coins, the observation of 2H, 1T is an event every bit as much as the observation of the elementary events of a single H, a single T, or even the 3-tuple of H-T-H in 3 toss space.
If my model with a presumed magnet predicts that the probability of 00 jumps from 1/38 to 1/19 given what my model of the new setup says, then I am stating “00 is now twice as likely to be observed as opposed to before with no magnet each and every time the wheel is used”. This is precisely how attribution statements in extreme weather events are phrased as well.
@victor
I know of no attribution statements in weather, climate, or any other complex field for that matter which state that any individual event at all is caused by a single factor. But you knew that already, I’m sure.
#60 Victor –
Indeed, if the magnet got stronger, and the effect got weaker that would suggest another factor at work. Perhaps that period was when they still allowed smoking in the casino, and the build up of tar worked against the magnet? I expect if that was the case if you looked at a long term record (and didn’t cherry pick a high to low start and end point), you might see that the trend didn’t really change. And given that you can actually measure the magnetic field strength and the tar build up on the wheel, and when you calculate their joint effect it matches where the ball ended up, you don’t really have any justification for thinking that you have suddenly overturned the basic physical laws describing magnetism.
Victor (@52) lives in a one-factor world. Don’t be like Victor. Live in the real world in which causation is complex.
#71 jgnfld,
My “issue” has been stated clearly multiple times… clarity of language, and clarity of concept with respect to cause and effect.
This usage is consistent… in science and out.
So, I say “make an attribution statement” is not the same as “attribute an event”, and I say “we don’t need the distribution to attribute individual ball locations to the presence of the magnet.”
You say you disagree, and then give an example of an attribution statement:
“00 is now twice as likely to be observed as opposed to before with no magnet each and every time the wheel is used”
But that is not at all the same as saying that:
“The ball falling into #8 on the first spin is attributed to the presence of the magnet [as opposed to no magnet].” (Same applies to some series of spins.)
I don’t know which comments of mine you have read so far, but I suggest going back to my original critique of rasmus’ language (#7) and follow it through to where we finally got with his #17.
If you still think you have some “disagreement”, perhaps you could articulate it more clearly.
MartinJB says: Victor (@52) lives in a one-factor world.
No, Victor lives in a logical world. The effects of industrial pollution tend to be localized. The effects of CO2 emissions are global. So if you want to argue that i.p. was responsible for the global cooling evident from ca. 1940 to ca. 1979, you would need to produce evidence from that period for CO2 induced warming blanketing relatively undeveloped areas, such as Africa, India, Central Asia, Siberia, etc., balanced by cooling in heavily industrialized regions, such as N. America and Europe. If such evidence exists then maybe you have a point. Does it?
Moreover: “Clean air” policies were limited to the Americas and Europe, but not Asia. Yet temperatures throughout most of Asia rose along with temperatures in the rest of the world during the period ca. 1979-1998. Since India and China, were burning lots of coal during this period, why didn’t temperatures fall there, rather than rise?
Also, sea levels have risen steadily since the 19th century to the present. Why wouldn’t they have declined or paused due to the effects of i.p.?
Weaktor@75: “The effects of industrial pollution tend to be localized.”
Citation fricking needed! Oh, wait. You don’t do those. You just pull random assertions out of random orifices.
Victor @75, those are valid questions, but there is much more to the issue. The flat period of temperatures mid last century is well explained by industrial aerosols, especially given that the flat period is most evident in land based trends, BUT is also related to the fact that total CO2 concentrations in the atmosphere were still limited by today’s standards. By the 1980’s filters had been fitted to coal fired plant in many countries and CO2 concentrations had increased enough to reach a critical mass and be a powerful factor in warming. So two factors were happening at once.
As you do point out Asia has not cleaned up their particulate emissions as well. And its noticeable because temperature trends have been flat in their most industrialised areas. But the net result is warming took off globally after about 1980 because of higher CO2 concentrations, and sufficient although not universal reduction in aerosols through filters fitted to coal fired plant etc.
Victor @75 “Also, sea levels have risen steadily since the 19th century to the present. Why wouldn’t they have declined or paused (mid last century) due to the effects of i.p.?”
The reason sea levels continued to rise during the flat period of global temperatures mid last century is a combination of inertia, and expansion of the oceans and melting ice in the antarctic and land based glaciers like the Andes and Himilayas, all of which were not hugely influenced by land based particulate emissions in the large industrial centres because they are located away from these specific regions. As you yourself stated particulate emissions are somewhat regional in origin and effects although they contribute to average global trends.
Victor (@75) employs his usual hand waving and special pleading to justify his one-factor world view. Unfortunately, he has no actual evidence, let alone quantified evidence to support his position. He has nothing quantifying how localized aerosol cooling is over different time periods. He makes no effort to quantify the relative forcing of aerosols vs. GHGs.
In fact, SO2 emissions in east Asia (principally China) never exceeded emissions in either NAM or Europe until the mid 80s. And SA emissions didn’t match NAM or Eur peak emissions until after 2000, by which point the CO2 forcing was substantially larger than it was in the 40s-70s and total SO2 emissions were still rather lower than the peak in the 70s.
What’s more, the most obvious regional differences in SO2 emissions were between the north and south hemispheres, and we see the temperature pattern you would expect. NH temps fell in the 40s through 70s but took off from the mid-70s through the current time. SH temperatures did not fall during that period.
Ray Ladbury says:
Weaktor@75: “The effects of industrial pollution tend to be localized.”
FL: Citation fricking needed! Oh, wait. You don’t do those. You just pull random assertions out of random orifices.
V: NASA: “. . . unlike many greenhouse gases, aerosols are not distributed evenly around the planet, so their impacts are most strongly felt on a regional scale.” https://earthobservatory.nasa.gov/features/Aerosols
MartinJB: What’s more, the most obvious regional differences in SO2 emissions were between the north and south hemispheres, and we see the temperature pattern you would expect. NH temps fell in the 40s through 70s but took off from the mid-70s through the current time. SH temperatures did not fall during that period.
V: Really? That’s not how it looks to me:
http://www.euanmearns.com/wp-content/uploads/2015/04/Shemis-station-aver.png
https://www.earth.columbia.edu/sitefiles/image/press_room/press_releases/2010/HemisphericTempChng-warmestdecade_300.jpg
https://sites.uci.edu/energyobserver/2018/01/21/warming-of-land-north-america-and-the-usa-through-2017/
Here’s the picture for the Arctic:
http://berkeleyearth.org/wp-content/uploads/2018/01/Arctic2017.png
As you can see, temperatures nosedived from 1939-1980.
As for Antarctica:
https://static.skepticalscience.com/pics/AntarcticTemperatureChange.png
No warming ’till the 1980’s.
So where on Earth, pray tell, is all the warming that “would have” happened were it not for industrial aerosols?
Victor @80
“MartinJB: What’s more, the most obvious regional differences in SO2 emissions were between the north and south hemispheres, and we see the temperature pattern you would expect. NH temps fell in the 40s through 70s but took off from the mid-70s through the current time. SH temperatures did not fall during that period.”
“V: Really? That’s not how it looks to me:”
https://www.earth.columbia.edu/sitefiles/image/press_room/press_releases/2010/HemisphericTempChng-warmestdecade_300.jpg
Victor the graph in the link plainly shows temperatures in the northern hemisphere trending down through middle of last century and temperatures in the southern hemisphere are flat or near flat. Your trouble is you cannot read a graph. I mean the difference in trends between the north and sounthern hemispheres is at the very least starkly obvious even although eyeballing a graph is not ideal. If you don’t accept the obvious do a statistical analysis. The bottom line is the very graph you posted proves the regional difference, and proves your own ideas wrong. Hilarious.
Weaktor, the effects are localized when the source is localized. When the source is spewing smoke as thousands of ships crossing oceans…, not so much.
re various responses to Victor,
Illustrating my original point about ignoring physics.
What popped into my head immediately on reading #62… really, reflexively, no thought… was “wait a minute, how would you know that the strength of the magnet was increasing??”.
Now, I’m pretty sure Victor would not respond to that question. But, by not asking it, y’all are just getting sucked in to the same old nonsensical back-and-forth about weather statistics. You are validating or enabling the (false) Denialist framing of the issue.
Analogies are often limited in utility, but in this case it offers an opportunity to discuss, for the hypothetical reader, how real physical science goes about establishing “the truth”.
I’ve come to think that a lot of people no longer have the advantage of experience designing experiments in the physical sense, which I think, like the prospect of hanging, tends to concentrate the mind… trying to get funding for time on the supercomputer isn’t really the same as when you will have to scrounge equipment, or build it yourself, to test your hypothesis.
You have a magnet and a little metal ball. How do you determine the strength of the magnet?
nigelj: “Victor the graph in the link plainly shows temperatures in the northern hemisphere trending down through middle of last century and temperatures in the southern hemisphere are flat or near flat. Your trouble is you cannot read a graph. I mean the difference in trends between the north and sounthern hemispheres is at the very least starkly obvious even although eyeballing a graph is not ideal. If you don’t accept the obvious do a statistical analysis. The bottom line is the very graph you posted proves the regional difference, and proves your own ideas wrong. Hilarious.”
V: nigel, SH temperatures both rose and fell, as is evident in all three graphs. The relevant point is that we see no sign of the warming trend one would expect due to the significantly accelerated rate of CO2 emissions during this period. Nor is there any trace of a warming trend apparent in the graphs for either the Arctic or Antarctic, where industrial aerosols could not have been much of a factor.
So my question remains: where on Earth, pray tell, is all the warming that “would have” happened were it not for industrial aerosols?
82 Ray Ladbury says:
“Weaktor, the effects are localized when the source is localized. When the source is spewing smoke as thousands of ships crossing oceans…, not so much.”
V: What no insults? Careful, Ray, you could be mellowing. :-)
So now it’s aerosols from ships crossing the oceans tamping down the temps. Looks to me like desperation, Ray. But hey, if you can provide some evidence I’d love to see it.
Zebra sez: You have a magnet and a little metal ball. How do you determine the strength of the magnet?
V: Simple. By measuring the density of CO2 in the atmosphere.
Zebra says “What popped into my head immediately on reading #62… really, reflexively, no thought… was “wait a minute, how would you know that the strength of the magnet was increasing??”
“But, by not asking it, y’all are just getting sucked in to the same old nonsensical back-and-forth about weather statistics”
I haven’t done much physics, but a google search reveals Magnetic field = permeability x turn density x current. (surprise, surprise). Therefore you know the strength of the magnetic field is increasing if the current is increasing, assuming its an electromagnet.
Maybe there is an equation similar in principle for working out if hurricanes are made more intense by a warming climate? But bear in mind such a thing probably has to be derived from some physical observations of hurricane behaviour versus changes in heat energy. Given you cant do experiments with hurricanes wouldn’t this have to rely in part on “weather statistics”?
Re. Victor
Rinse lather repeat.
The points that Victor raises have been brought up by him on this forum multiple times in the past and discussed ad nauseam in the greatest detail over and over and over again.
Why is this allowed?
Note comment policy…“Please note if your comment repeats a point you have already made….please reflect on the whether you are using your time online to the maximum efficiency.”
Victor knows this, but has his self-serving motives so he must believe he is using his time effectively for his own self-promotion; however, sadly it is at the expense of everyone else’s time.
I’m not playing his game anymore.
Sigh.
Victor @84
“nigel, SH temperatures both rose and fell, as is evident in all three graphs.”
No they didn’t, and with respect that’s not the point anyway. There is an obvious huge difference between northern and southern hemisphere temperature trends for the middle of last century. The northern hemisphere temperatures fell quite markedly, the southern hemisphere is near flat if you do a proper lowess smoothing line. In any event its the difference between the two trends that is more important. Aerosols tend to remain in greater concentration near their source which was mainly the northern hemisphere so easily explain the difference in the trends. They would have had SOME EFFECT on the southern hemisphere partly explaining the rather flat trend there because of drift, and the southern hemisphere did have some industry just less than the north.
” The relevant point is that we see no sign of the warming trend one would expect due to the significantly accelerated rate of CO2 emissions during this period.”
To repeat my previous comment, temperatures were flat during the middle of last century in the global data averaged over both hemispheres . During this period concentrations of CO2 were low, and industrial aerosols were high, and this easily explains the flat trend, and by the 1980’s this had changed to increasing temperatures, and we had higher atmospheric concentrations of CO2, and fewer aerosols, that explain the increasing trend well. It’s not that complicated to grasp. Only two variables.
“Nor is there any trace of a warming trend apparent in the graphs for either the Arctic or Antarctic, where industrial aerosols could not have been much of a factor.” So my question remains: where on Earth, pray tell, is all the warming that “would have” happened were it not for industrial aerosols?”
Sorry aerosols would most certainly have drifted over the arctic. The antarctic had a flat temperature trend mid last century, it didnt drop as sharply as the north, and would still have had some limited effect from aerosols, because they don’t all remain in one hemisphere and latin america did have some industry.
Like CC Holley Im tired of Victors game, not sure why Im bothering with it, I must be mad,
CCHolley: The points that Victor raises have been brought up by him on this forum multiple times in the past and discussed ad nauseam in the greatest detail over and over and over again.
V: Not so. While I’ve pointed to flaws in the industrial aerosols hypothesis before, most of the issues I raised recently are very different, and much easier to evaluate. Sorry you can’t see that. Once again, let me repeat: where on Earth, pray tell, is all the warming that “would have” happened were it not for industrial aerosols?
And sorry, Ray, but
Sorry again, Ray. My response to you got cut off in that last post. Here’s it is in full:
And sorry, Ray, but
“Ship tracks increase the albedo, yet have very little effect on the long-wave radiation balance, because they are so shallow. Therefore ship-tracks tend to cool the global climate, although the magnitude of this effect is likely to be small.” http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/contrail.html
CCHolley:
“Victor knows this, but has his self-serving motives so he must believe he is using his time effectively for his own self-promotion; however, sadly it is at the expense of everyone else’s time.”
Victor is a musician. There’s a lot of repetition in music, and a lot of fixation on pieces composed hundreds of years ago :)
Victor, local radiative imbalances will impact temperatures globally. Small impacts add up. The SH did not see a multi-decade period of cooling like the northern hemisphere. You just throw nonsensical spaghetti at the wall, but none of it sticks.
You’re the Dinesh D’Souza of the RC comment sections.
Victor fails again. And with very little amusement value this time; it’s just boring “I don’t see it.” Hell, V, we already knew that!
Sigh.
Weaktor, Sulfate aerosols have a longer lasting effect over larger areas–and heavy fuel is rich in sulfur.
re: faites vos jeux,
I was hoping for jgnfld to join back in but at least my simple question got Victor to panic and expose his blunder.
Any child who has played with magnets would say that you put the little ball on the table, slide the magnet towards it, and see how far away the magnet is when the ball starts to move.
The point, in terms of physics and language:
If some metallurgist asked me to determine the magnetic properties of a new alloy, I might try to do some theoretical analysis on the molecular structures, and then I would make some direct measurements, perhaps with a torsion balance, for example.
What I definitely would not do is tell her that she must make it into a perfect little ball, and also buy me a roulette wheel, so that I can establish a distribution of numbers when I attach a magnet…..
We attach the magnet to the roulette wheel only if we already know that it will attract the ball, just as we know that increasing CO2 will increase the energy in the climate system.
So, the point of “attribution studies” is not to determine if we can cheat at roulette; we know that where the ball lands on each spin can be attributed to the presence of the magnet. Rather, the point of the exercise is to “calibrate” or “fine tune” our nefarious scheme, to maximize gain while still avoiding detection.
But when we incorrectly say, and encourage journalists to say the words: “we can’t attribute any single event to [increased energy in the system]”, the implication is that we are engaged in the absurd experiment I described above with the new metal. (And then, of course, you get the absurd arguments from Victor and KIA et al.)
1940-1980 — temperatures
Africa: https://www.hoover.org/sites/default/files/giordanopicture1_copy.jpg
Clear downward trend through ca. 1979.
Alaska: http://oldclimate.gi.alaska.edu/Fairbanks/graphics/fai_temp_1906-2012F-lrg.png
Clear downward trend til late ’60s. Strong upward trend through most of the 70’s, followed by another downward trend til late 90’s.
Madagascar: https://bobtisdale.files.wordpress.com/2018/12/figure-121.png
Follow the red line. Slight downward trend until the late 70s. (Note also the extreme downward dip in Norway — see blue line.)
Australia: https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Australia-temp-anomaly-1910-2009.svg/450px-Australia-temp-anomaly-1910-2009.svg.png
Ups and downs. No clear trend.
Musn’t forget Kirensk and Tura (look ’em up): https://www.john-daly.com/stations/kirensk.gif
No upward trend. Either downward or flat.
So where oh where in the world can we find some sign of that underlying warming trend from 1940-1980?
Oh wait. I found one. The Solomon Islands: http://berkeleyearth.lbl.gov/auto/Regional/TAVG/Figures/solomon-islands-TAVG-Trend.png
That’s the ticket!
Re. Victor @91
“…where on Earth, pray tell, is all the warming that “would have” happened were it not for industrial aerosols?”
As discussed a thousand times…masked by industrial aerosols, there is no flaw in this conclusion. The models hindcast this period well with the exception of the early 1940s warming which was the result of a warm bias from a change in ocean surface temperature. It is not a mystery no matter how Victor attempts to spin it.
Rinse lather repeat.
Victor @97, you dont provide a source for that African temperature data, and Australia only shows a dip for 1940 -1955 which is too short to be hugely significant. There is no point cherrypicking a few places like this, it doesnt demonstrate anything compelling.
“So where oh where in the world can we find some sign of that underlying warming trend from 1940-1980?”
Nobody has claimed there is anywhere with a warming trend from 1940 – 1980. A few places probably do, but everywhere I’ve come across is either flat temperatures, or falling temperatures. Both are easily attributed to the COMBINATION of low CO2 concentrations and industrial aerosols. Aerosols are concentrated in the northern hemisphere because more industry is there and they linger around, but some does spread globally and some do originate in the southern hemisphere.
I asked myself similar questions to you about 15 years ago. I understand your suspicions, but the answers are compelling. Learn and move on.
This study is the kind of thing done by people who know nothing of reproducing natural systems. Why, in the name of whatever gods that be can’t a scientist consult with people who have valuable info they might use?
Same goes for those responding, for the most part. You have resources. Use them.
The danger lies in *exactly* what we have seen with this study: Parts is parts and authorities are authorities and people love easy answers. That is, they will listen to supposed authorities say something like, “Well, if we plant a lot of trees, somewhat mindfully, we could sequester some useful amounts of carbon,” but they hear, “Plant trillions of trees! Any tree! Almost Anywhere! Go! go! Go!”
It’s goddamned irresponsible.
Then you get the critiques and criticisms coming back that are just as freaking ignorant! “What? Uh-uh! There’s a golf course there! That’s too close to a school! It takes 800,000 years!”
Sigh…
So, people, let’s get more interdisciplinary work going, shall we, and avoid all this #$%^ery?
The biggest issues with this study and the responses are:
I. No tree should ever be planted in isolation.
Ib. Grow forests.
Ib1. Let forests regrow rather than reforesting as studies indicate they regrow faster w/o human help.
Ic. Grow guilded trees. (Co-plant supportive/symbiotic species.)
Id. Better yet, grow food forests.
These steps significantly increase the carbon sequestered, particularly if managed directly, by increasing the biomass in any given sq meter of space above and below the soil; provides greater food supply and food security; localizes food supply; can provide biomass for other industrious use, such as lumber from over-story, and on and on.
If nothing else, any “plantation”-esque mass planting should include support species – similar to guilds that help the trees grow even if they are not part of the apex system. For example, legumes for nitrogen, deep-rooted plants for soil-building, nutrient accumulation (a la comfrey), etc.
2. Any mass planting that survives *will* affect the local climate in small and/or large ways by affecting the water cycle, soil hydration, fauna migration/expansion/replacement drawn by/to/ or repulsed by the trees/forest, soil structure, etc.
2b. Such a new plantation/forest/reforestation will affect hydrology potentially far away and even globally. Blindly planting out global water cycle-altering numbers of trees is FLAT STUPID.
3. Such mass plantings should be done via planning spanning neighborhood, city/area, regional, bio-regional and inter-bio-regional planning, as I have suggested in my Regenerative Governance model for local to global multi-tiered, semi-autonomous, fractally-structured egalitarian problem-solving.
3b. Planting w/o planning will be chaotic and have chaotic effects across the physical and socio-politico-economic spectrum by disrupting processes globally, some positively, some negatively, and the difference between the two is where the greatest danger lies.
3c. Such changes *are* needed and provide an excellent impetus for ecosystem restoration, new governance (economic, social, political, resource use) models, simplification, localization, etc.
4. We must change the condition of the planet holistically, with system-based, human-natural integrated systems globally, even in cities (which logically must be greatly reduced.)
4b. There are people who know how to restore, recreate, modify to maximize the Nature/human Nature nexus, yet they are not invited to advise scientists, to guide their project designs, work with communities, gov’ts, or anything else.
Doesn’t mean we’re waiting for the rest of you to pull your heads out:
https://www.ecosystemrestorationcamps.org/
Basically, such schemes, much like the idiotic Green Suicidal Deal, if not done as a whole system are bound to fail to meet the challenges we face as they will be based on delusional wishful thinking.
https://www.youtube.com/watch?v=2xZ7nfC7BQk
https://www.youtube.com/watch?v=2xZ7nfC7BQk
https://www.farmcarbontoolkit.org.uk/carbon-farming-science-behind-it-all
Actually, the southern hemisphere did see a warming trend mid-century:
https://tamino.files.wordpress.com/2010/08/hemitemp.jpg
The blip in the 40s doesn’t change that. In fact, that blip all but disappears if you look at the land-only data, suggesting it has something to do with marine temperature readings:
https://tamino.files.wordpress.com/2019/01/berkland.jpg
re 101 MartinJB
Thanks, Martin. Actual evidence is always welcome. However, the smoothing in the graphs you’ve linked to is misleading, giving the impression of a continuous temperature rise, which was by no means the case. If we direct our attention instead to the individual data points we see a roller-coaster pattern, full of abrupt changes of direction, up-down, up-down until the 1970s, when an upward trend does, finally, become apparent. If temperatures were responding to the decisive increase in CO2 levels apparent during this period, we’d expect to see a clearer upward trend, not the see-saw pattern so evident in your graphs.
In any case, a careful, critical study of worldwide temperature distributions during the period in question would be necessary, I would think, before any conclusion could be drawn regarding the hypothetical existence of some underlying warming trend, masked by aerosol cooling. I’m wondering whether such a study has ever been done, and if not, why not?
Victor @109
“Actual evidence is always welcome. However, the smoothing in the graphs you’ve linked to is misleading, giving the impression of a continuous temperature rise, which was by no means the case. ”
No it is not misleading. Smoothing is a mathematical process that conceals nothing, and instead it throws light on whats happening. It doesn’t matter that the trend is not a continuous temperature rise, its obviously bumpy, but the trend slopes modestly upwards overall
“In any case, a careful, critical study of worldwide temperature distributions during the period in question would be necessary”
We already have the global graph we are discussing, which is based on country by county data!
Come back to basics. It doesn’t matter too much about the exact degree of warming mid century. Temperatures in the northern hemisphere fell very noticeably, and this is where most of the industrial aerosols are concentrated and tend to linger so no surprise there they pushed temperatures down.
Temperatures in the southern hemisphere clearly follow a different trend, they warmed slightly overall, but fell slightly in some places like Africa over land, but the point is they did not fall as much as the northern hemisphere. This is clear in the graphs people have posted.This pattern is ALL consistent with less industry being in the southern hemisphere, and some drift of aerosols from the north so temperatures were pushed down, but NOT AS MUCH.
The temperature trends are therefore well explained by the behaviour and location of industrial aerosols. You don’t need a science degree to see this.
This website needs to pull the plug on Victor. You are shooting yourselves in your own feet in the name of free speech or something. All his crap should at least go in the borehole.
I see Victor Grauer of Pittsburg PA is back here trolling his way down the comment threads of RealClimate. Apparently the climate is too “up-down, up-down” for any trend to be driven by levels of atmospheric CO2.
Of course, it is plain that since first arriving here (back in 2014) Victor has learnt absolutely nothing to replace his denial of AGW, instead wielding a succession of preposterous ideas to support his grand delusion that there is no correlation between CO2 levels and global temperature.
Now it seems that Victor the Troll objects to the findings of science of climatology because global temperature displays too much uppy-downy-ness for such a relationship. (I note ‘uppy-downy-ness’ was the theme of Victor’s last intervention here at RealClimate although back then it was more a contrarian version: you say up, I say down.)
Victor the Troll, perhaps in your recent absence from RealClimate you missed this post back in April on Willeit et al (2019) ‘Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal’ which demonstrates the true ‘uppy-downy-ness’ of global climate, all driven by such things as CO2 levels for the last 3 million years.
Victor 102: If we direct our attention instead to the individual data points we see a roller-coaster pattern, full of abrupt changes of direction, up-down, up-down until the 1970s, when an upward trend does, finally, become apparent. If temperatures were responding to the decisive increase in CO2 levels apparent during this period, we’d expect to see a clearer upward trend, not the see-saw pattern so evident in your graphs.
BPL: This is a persistent misunderstanding of Victor’s. He thinks if one curve is jagged and another is smooth, there can’t be any correlation between the two. He refuses to accept the actual definition of correlation, and doesn’t seem to understand the existence of noise as opposed to signal.
Victor, #102–
And I’m wondering if Victor will do the requisite search, and if not, why not?
Victor, you DO like to be fooled by noise. The fact is quite plain that the SH did not undergo the same protracted cooling as the NH.
You are free to insist that a particular analysis would be needed to demonstrate that aerosols were responsible, but since you also don’t know how regional and over what timescales SO2 should have an effect your objections really aren’t worth much. The global signal is evident. Your sandcastles of unquantified reasoning do not constitute worthwhile arguments. Your own “logic” can be just as attractive a deception as noise.