With what may be the warmest year in centuries about to close, I thought it would be fun to have a graphic comparing the march of global average temperature over several years about a century ago with the present state of affairs. This graphic is based on NASA's data, using John Abraham's estimate for the 2014 temperature (it might end up being a tiny bit different). There is more information about those sources here.
[click on the graphic to get to a larger version]
Just to be clear on how to read the graph ... the red dot is not anywhere in particular on the horizontal scale. The X and Y axis simply plot global average temperatures estimated for 1895 to 1933, a series of years that has 1914, a century ago, in the middle of it. This early sequence of data is meant to represent "pre-industrial" temperatures, and here that is compared using the single red to today, positioned correctly on the vertical scale (of temperature). Note, however, that 1895 to 1933 is not really pre-industrial. Human produced greenhouse gases were already being added to the atmosphere by then, though not to the same degree as more recent decades.
You will hear people say that even if 2014 is the warmest year on record, that it is not statistically significantly warmer than the next warmest year. That is absurd. One would have to have a very poor understanding of how statistics works to make such a statement non-ironically. But to make the point even more clear than I might if I explained why that is a dumb thing to say, statistically, I produced this graph which shows that today it is much warmer than it was not so long ago.
ADDED: A question has been raised as to whether or not I chose the proper scale on the Y-axis. I did. My intention was to show variation and average temperatures for several decades near the beginning of the industrial period, centering on 100 years ago, and to put the current year in context of that. This graph does that nicely, with no strangeness about axes other than the carefully explained fact that the clearly labeled 2014 datum is not scaled to the time scale on the bottom. The nature and variation of the entire instrumental curve is readily available and there are dozens of graphs here on this blog and elsewhere that show this (I placed one at the top of the post for your convenience). The point of this graph was to remove the ascending values and obviate the rather absurd question of statistical difference between the highest and second highest ranked years. As explained.
But the Y-axis problem emerges as a more general climate science denial meme (other than, and beyond, the relatively valid and honest question of how to best scale the Y-axis on a graph like this). And in relation to that, I've made a NEW ENTRY IN MY FAQ. Please have a look. There are some fun graphs.
To demonstrate two ways in which people get this wrong. First, an actual scientist type person simply believing (incorrectly) that all scales must start at zero (maybe they do in his field), and second, a climate science denialist actually arguing that the joke graph shown in the tweet is the best way to show global temperature change.
You might have to click on the pic to be able to read it:
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Stunning very telling illustration thanks for this Greg Laden. Indeed we have made a graphic difference.
Good manipulation. One can learn from you.
First rule to exaggerate an effect is not to start the graph at zero. Next time you could choose something with a logarithmic scale.
Hans, the "zero' idea here sounds right to people who have heard about that method of lying with stats, but that actually is not appropriate here.
What is "zero" in temperature? Zero F? Zero C? Zero K? Do you really want me to start with Zero K? Do you have any idea what that would mean?
An appropriate vert. scale for global temperature is a scale that incorporates all the values you are looking at in a given system, I suppose. Here we are looking at pre-industrial and current temps.
Yes, Hans, one can learn from me. And you just did! Good for you!
Well I for one am of the opinion that the human race is screwed. The will to make sacrifices now to make a difference in the future just doesn't exist in government circles, and ordinary Joes like us can only do so much. The lag effect of global response to greenhouse gases means it is gonna get much hotter quite soon and nothing will stop it.
Hans, I've been meaning to write this up for some time now, and your question inspired me to finally do it. Check this out: http://scienceblogs.com/gregladen/about/#ZeroKelvin
A couple of years ago, I came down with a nasty viral infection. Developed a 103F fever. Was about to call the Dr's office when the fever broke.
Looking back, I now realize that I should have applied Hans' logic and stopped worrying. After all, a 103F fever corresponds to less than a 1% increase in body temperature.
So what was I getting all worked up about??
Hans: The purpose of a graph is to maximize communication of information. A log scale certainly wouldn't do that here, not would a scale that starts at zero. The reader would learn almost nothing from either.
Greg, nice to see that one can be inspired even by a climate change denier! :) Sometimes I think their sponsors give them a handbook with negative comments, which they mostly apply randomely without understanding them...
David: Thanks for mentioning the log scale, I had forgotten to address that. Asking for a the axis to be set at zero, and to use an absurdly large scale measure, at the same time as asking for a log scale, is major double dipping.
So, the temperature 100 years ago was the "right" temperature for the globe, and today it's not? I still can't find anyone who can tell me the optimum temperature for the planet.
How accurate is the global temperature from 100 years ago? With the station drop-out issues and UHI, I don't think current temps can be trusted, much less older, constantly adjusted temps.
pinroot, the temperature right now is much higher than most times in tend of thousands, maybe hundreds of thousands of years, and it is expected to get much warmer, so yes, essentially, you have that right.
You are poorly informed about the quality of the instrumental record.
Pinroot: The "right" temperature would be the one closest to the conditions on which human civilization was founded and all it's major infrastructure was built. If you are Ok moving all the human race's ports inland and famrs poleward, warmer tems are fine. (Well, not fine: we'd lose a lot of biodiversity, but that's a soft cost. Moving farms and ports is a hard cost.)
When people like Pinroot claim to not be able to think of any problems that could be caused by a relatively sudden change in the average temperature of the atmosphere and oceans of an entire planet, I kind of don't believe them. Still more when they claim to be unable to find examples or explanations thereof despite looking. This is "playing dumb," and thinking you're being clever by doing so, thus actually being dumb in a way you didn't intend.
Michael Wells and claimsguy,
Still, you are letting pinroot and others frame the debate.
The average temp argument is about energy balance relative to the sun and space.
The negative effects for humans are about how that energy balance plays out in the complex system of the climate.
So, if all that ever happens is that every point on Earth experiences a yearly averaged 2 degree temp rise, they have a valid point. Arguing about the GMT graphs just lets them imply that; sadly the public thinks "average" means "typical".
For Greg: I'm not an expert on the 'cost' of putting up graphics but I don't see why we don't provide finer grained data like seasonal or monthly, or regional, graphs, which may be more compelling.
Like the hockey stick, this is a clear and powerful illustration that can be understood by anyone. It should be widely disseminated.
The video linked to below makes a point that's worth emphasizing. Under circumstances of normal variability we would expect to see as many cold as warm records. The last global cold record was set in 1911.
Do you think it looks like a hockey puck ....????
An ice melting red hot hockey puck.
In Denmark the previous record from 2007 was broken by 0.5°C. The average temperature for 2014 is 10°C – our first time ever in double digits.
“ 'Hvis vi antog, at Danmark ikke var ramt af klimaændringer, men havde et klima svarende til 1961-90, så ville år med en gennemsnitstemperatur på 10,0°C kun forekomme naturligt med omtrent 700 års mellemrum. Det er altså en meget usandsynlig hændelse', fortæller DMI's forskningschef Katrine Krogh Andersen og fortsætter:
'Antager vi derimod, at vi har oplevet en jævn opvarmning, ja så vil år med 10,0°C forekomme med 18 års mellemrum på nuværende tidspunkt og endnu hyppigere i fremtiden. Temperaturer som i år vil blive mere og mere almindelige'.
(“If we suppose that Denmark wasn't affected by climate change, but had a climate corresponding to 1961-90, then years with an average temperature of 10.0°C would only occur naturally around every 700 years. This is thus a very unlikely event,” states DMI's head of research, Katrine Krogh Andersen, and continues:
“If, on the other hand, we suppose that we've experienced a steady warming, well, then years with 10.0°C would occur every 18 years at the present time and more often in the future. Temperatures like this year will become more and more common.”)
The maps at the top of the page show the difference between the previous record year, 2007, and 2014.
cosmicomics: "Under circumstances of normal variability we would expect to see as many cold as warm records."
As in my earlier comment, I wonder if we encourage misunderstanding sometimes, or allow others to do so. Should we really "expect to see records" at all? Absent a trend, who knows, unless it's a trend in variability. You might need a very long time series.
Much of the public is obviously convinced that if there isn't a "record" every year then there is no warming. Maybe a term like "outlier" (other suggestions welcome) is clearer; if you look at the first graph the trends for the higher values and the lower values are quite striking.
As I also said earlier, not being a blogger I don't know how much trouble it is to produce these graphics for presentation. But my inclination is to respond to the 'skeptics' with more detail, since that is much harder to explain away.
More correctly stated, if variance in a measure (e.g. temperature) remains constant over time, we should expect to see fewer records as the record itself lengthens.
I'm not happy with the term "outlier" because it means a datum that is outside the range either by chance or for reasons of measurement error or confounding effects. The record warm years (which have all happened in recent years) are not outliers, but rather, indicators that the best way to characterize the distribution of temperatures over time is with a trend model over time. Record warm years are not outliers, but rather, the expected result of an upward trend.
The point of this graphic is to reduce detail. But graphics that emphasize detail are also helpful.
@16. cosmicomics : Good clip and comment there - thanks. for that. Guess you may have seen it but this short clip :
'2014: Hottest Year on Record?' from climate centraldotorg also makes a good if very short graphic on this esp. at the end looking at previous averages and directions as does the longer version (1 min 11 secs) of the clip used in that AlJazeera America interview seen in full (I think?) here :
It would be interesting to compare the ten hottest and ten coldest years on a chart. Fourteen of the past fifteen hottest years have come since the last century.
Hmm . Does anyone here know what the top ten coldest years were and is able & willing to put that particular comparison table together? Top twenty of each even? Please? (Sort of been vaguely looking for that data myself and not yet found it anywhere.)
I think the hottest years show a definite trend whereas the last coldest year could well have been an outlier - in other words a point on the graph that is extreme and contradicting the rest of the pattern or norm. (As I grok it, could well be mistaken not being a statistician or great at maths.)
If you mean average global temperature as I presume you do then correct. Todays average - and more importantly the trend it is on - indicates an overheating problem our planet is suffering. The engine light for Spaceship Earth has lit up and the increased heat is already causing trouble.
How hard have you looked? Can't be very - anyhow this is answered very nicely for you by #12. claimsguy & also in the following comment by Michael Wells.
Have you by any chance heard of the BEST project by former climate skeptic and physicist Richard A. Muller? No? Watch this :
Seriously. Please. Watch and think about that above linked clip - and the others in that 'Climate Crocks' series are superb and informative viewing that I'd highly recommend too.
Multiple studies, a whole team of hockey sticks derived by a whole range of records and proxies all come to the same conclusions. Yes Human-Induced Rapid Global Overheating (HIRGO) is a real and serious threat to our lives, our environments natural and artificial and our future prosperity.
If 98 of out 100 doctors told you that you had a problem would you listen to them and start acting according to what they told you - especially if the other two were quacks who were being paid to and had vested interests in saying otherwise?
Even if you personally would choose believe the two quacks over the 98 doctors; how do you think most every sane and reasonable human is going to answer that question?
Well, ninety-eight out of one hundred climatologists - people who are as expert in their field as medical doctors are in thiers, who have studied and dedicated their lives to all the complexities and quirks and facets of climate science - say HIRGO is real and serious and we need to act accordingly now.
"More correctly stated, if variance in a measure (e.g. temperature) remains constant over time, we should expect to see fewer records as the record itself lengthens."
I would prefer: "more formally stated". But your attempted translation isn't capturing my intent, which is again to get past the superficial when responding to Denialism.
I still don't "expect", given only the graph, anything. What you said is really kind of circular-- how do we observe that the variance is constant over (future) time without also noting the absence of records in the record? You really mean "if we assume constant variance in the future...", right?
My "expectation" (conjecture, based on physics intuition) is that variance is going to vary even more. I also "expect", more confidently, based on physics, that the trend obtained starting in 1979 and using combined data sets will remain within a narrow range as more years are added. But I expect with great certainty, if my conjecture is correct, that we will be hearing even more "you didn't predict X" and "no warming for N years."
So, my original point: I guess I'm burned out hearing, over a decade plus, the same back-and-forth about this one metric-- it's like Bible scholars debating with fundamentalists, but never bringing in their knowledge of actual history, and letting the discussion be just about the words in the book, subjectively interpreted.
Climate change is a physics problem, and the physics is in the details-- in the finer grained measurements. That's where the answers to "UHI" and "pause" and so on reside.
Astro, the problem is you can't compare the instrumental record with the pre instrumental record on a year by year basis.
Zebra, I'll say it again from the hip, but I"m pretty sure my story isn't going to change.
Given a constant mean and an unchanging pattern of variance in a sequence, as one progresses through the sequence the frequency of new record values will decrease.
The second value will be a record. The third value has a high chance of being a record. Over the first few dozen values you'll have a few records. After you've had one billion vallues, the chances of having a new record beating all other records is nearly zero. In between the change goes down.
If that isn't clear may be you are reading too much into it because it is trivial. Nothing circular, it is correct, and I've not stated it formally because that would have invoked an equation.
I'm not trying to (nit) pick a fight here. I realize you may not have the time or inclination to have carefully read through my comment to understand my point. Your statement is indeed trivial--perhaps that's a better term than circular-- and incomplete, and doesn't capture what I am trying to say. See if you agree with this:
1. Variance could be constant or decreasing, with zero trend. We would then see fewer records over time.
2. Variance could be increasing, with zero trend. We would then see more records.
3. There could be a non-zero trend, with decreasing variance, which for a time would result in fewer records.
4. In case (2) we might be arguing about whether the measurements were 'outliers' in your sense, or 'real' local maxima. In case (3) we might be arguing about whether there is a 'pause'.
In no case should we be "expecting", based on the data *in isolation*, anything.
I don't understand where you're coming from, I don't understand what you're trying to get at. The remark you quoted was not about expecting records. It was about the contrast between the expected ratio of record highs to lows under conditions of normal variability and the now almost 90 years of record highs without lows. Since 1926 there have been 19 new record highs and no record lows. My point is that we have gone beyond the variability of the past (and that natural variation as an explanation for rising temperatures is not valid.)
“Should we really 'expect to see records' at all?”
Under present conditions we certainly should. Higher concentrations of greenhouse gases lead to increased warming. The heat trapping quality of CO2 has been known for more than 150 years. Higher concentrations of greenhouse gases have been measured. This is the fundamental reality. If we're talking about what is now a counterfactual situation – climate unaffected by human activity, then, as Greg wrote, the frequency of new highs and lows would be influenced by the length of the record, but we would still expect the ratio of high records to low to be approximately 1:1.
“Much of the public is obviously convinced that if there isn’t a 'record' every year then there is no warming.”
I have never spoken to anyone who has suggested that. I have never even seen that argument from a climate septic. If it's so obvious, you should have no trouble providing a link to a reliable source that backs up your claim. (Or is it that you yourself have trouble accepting that an unequivocal trend isn't synonymous with yearly records?)
Finally, if you believe that you can convince climate septics with better or more detailed information, you're wrong. The septics are not interested in logic, evidence, or honesty. Their focus is on denial, and they deny any way they can.
(The Danish word for nitpicking is flueknepperi, fly fucking. Thought you should know.)
I've been at this a long time, so I am well aware that there are many we will never convince. But then, why are you (we) here making comments? The answer is, of course, because we dream that there are these unbiased lurkers, and because we like to think we each have the best way to explain things so they will join 'our side'. My way is based on my experience of teaching, where I had the most success by asking questions and making people think, not by giving pronouncements from on high.
Now, as for needing new records every year-- of course, that is exactly the justification for "the pause". They argue that if there is not a monotonic progression, it is all a hoax, because the CO2 increase *is* monotonic. You haven't heard of this? You are not much of a climate change warrior if you haven't.
I would be happy to explain what you don't understand if you would tell me, instead of repeating what you (think) you do understand. Do you disagree with my numbered points in the previous comment? Or anything specific?
Zebra 26, I was with you until you said "In no case should we be “expecting”, based on the data *in isolation*, anything." In isolation of a physical theory of atmospheric physics and insolation? Then yes, but we do have such a theory. But yes, all your other points to characterize the situation correctly for number of time like this. The term "outlier" may be informal, but an outlier, to me, is a number that you've argued can be tossed in making estimates of population parameters. Must run, will return to conversation after breakfast at pancake house.
Once Mark Morano tires of advertising how flat the surface temperature graph in Kelvin graph appears, CFACT and Heartland will move on to the microwave background temperature-- how can anyone believe in global warming when 4.6 Kelvin is infinite in all directions ?
You assert that “much of the public” reasons as follows:
As a new record wasn't set last year, there is no warming.
Even the septics don't make an argument as foolish as that. Their argument is no warming since e.g. 1998, or for e.g. 17 years. Again, if you wish to prove that your “much of the public” claim isn't bullshit, provide documentation from a credible, linked to source. A failure to cite research that substantiates your claim will be proof that your claim is nonsense and that you make things up.
Your style of argumentation is identical to that of many climate septics. You make an outlandish statement that needs to be proven, and declare it to be obvious:
“Much of the public is obviously convinced that if there isn’t a ‘record’ every year then there is no warming.”
In your following reply obviously becomes “of course.”
“Now, as for needing new records every year– of course, that is exactly the justification for 'the pause' ”.
You don't document, you simply repeat.
A typical septic opening is to say, “Everybody knows that...,” and follow that with a statement that is in conflict with climate science. No documentation is provided, and when specifically asked for documentation, none is offered. This is what you do, and admitting that your statement was wrong appears to be beyond you.
As to your three questions, I consider them to be meaningless exercises in scholasticism, like examining the number of angels that can stand on a pin, or how one best can catch a unicorn. The evidence for the warming trend is incontrovertible, and questions that ignore this are irrelevant.
To conclude: You see yourself as a climate warrior. I see you as someone with a very inflated opinion of himself. If you wish to show that you know what you're talking about, this time you will reply by linking to research that backs up your assertion that “much of the public” – not one or two extraordinarily stupid climate septics – requires a new temperature record every year in order to believe the Earth is warming.
"In isolation of a physical theory of atmospheric physics and insolation? Then yes, but we do have such a theory."
Yes, we have a sound theory of energy balance (not "insolation"), but it is not particularly useful for making short term predictions. If you read #24 again perhaps you will see that this is the important distinction to me-- true whether Zebra's Conjecture is correct or not.
Twenty-plus years ago, perhaps the Global Mean Surface Temperature was the only serious metric we had. But having extorted all that grant money from the taxpayers, we've managed to get an amazing amount of science done in between the parties and junkets.
So, why are we we still enabling the misconception fostered by the Denialists that GMST is exclusively probative, and that the energy balance is open to question? Do we still doubt our own basic physics?
You may live in a more enlightened country than the USA. Here, we still have a majority that rejects Evolution. There is a 'hard core' of maybe 35% that will reject anything that President Obama agrees with, as directed by Rush Limbaugh-- when Rush (and Fox News) tells them that "there hasn't been any warming in 15 or 18 or whatever years", they will repeat that; we see it in comments all the time. There is perhaps another 10% that are smarter but will pick up that argument and use it.
Is that statement based on requiring a seemingly monotonic increase? From my direct experience with many freshman physics students, yes, that is what they are thinking-- it is not an unreasonable intuitive misconception if you only have a high school (USA) education. They are not distinguishing between trends, smoothed data, and full data.
So, cosmo, if you want to think for yourself and criticize my arguments, I will be happy to discuss them. I am not interested in trading website references.
"So, why are we we still enabling the misconception fostered by the Denialists that GMST is exclusively probative, and that the energy balance is open to question? Do we still doubt our own basic physics?"
I just don't see that happening. Perhaps my own blogging reflects what climate scientists and science communicators talk about in general. I've written far more words about non GMST measures than about it, and that which I've written about GMST has almost always been about how that is only part of the story. Just follow my first link back, then from there, go to "http://scienceblogs.com/gregladen/2014/12/03/2014-will-not-be-the-warme…" ... very hard to argue that I'm facilitating GMST as "exclusive probative" and I know I'm not unique among my colleagues.
So, yes, but we are on it already, and have been all along!
I would say that 35% is a conservative estimate for the hard core, and then there is the overlapping set of 12% that believe they were abducted by aliens while Bigfoot was watching (and the 1% that think they are aliens or Bigfoot, so that actually all works out pretty well).
“From my direct experience...”
My direct experience tells me that the sun goes around the Earth. It's only through familiarity with the knowledge gained by others that I have another understanding of our solar system. If we limit climate discussions to personal experience, we're left with “it's cold where I am now.”
“Is that statement based on requiring a seemingly monotonic increase?”
A non sequitur.
“So, cosmo, if you want to think for yourself and criticize my arguments, I will be happy to discuss them. I am not interested in trading website references.”
In other words, thinking for oneself involves relying on direct experience and ignoring research done by others. Credibility is achieved by saying “trust me,” not by offering proof. You can't provide a shred of credible evidence for your assertion, so your fall back position is that evidence doesn't interest you.
I'm sure you know more science than I do – almost anyone does. But logic, honesty, and academic rigor are not your strong points.
Actually, I'm pretty sure you can recognize that the sun is at the center of the universe using simple materials found in the average kitchen or garage.
Looking through a colander?
Second, I would have to know that it can be done and how it can be done. But the problem of direct experience starts before that, so...
First, in order to perform that experiment, I would already have to know that – despite my personal experience: the sun rises and sets, the Earth doesn't spin, because if it did I'd get dizzy, etc. – the Earth goes around the sun. The experiment wouldn't provide me with new knowledge regarding the solar system, but would confirm knowledge that I already have from others. If the experiment didn't show that the sun is the center of our solar system, I wouldn't conclude: heliocentricity is a hoax! I'd conclude that the experiment had failed because I did something wrong.
If you figure out that the earth is a globe and estimate the size, that would help (that was done thousands of years ago by some). Once you know that, it is easy to assume that the earth moon, and sun move around in relation to each other. It is also easy to conclude that the sun and the moon are not disks, but rather, round like the sun. Once you know that you know that the moon rotates once every lunar month. So now you've got things rotating. Then, you know that the moon is closer than the sun. Other size and movement relationships could be worked out.
I'm pretty sure you can get pretty far with a sense of time, a measurement of distance, and a stick.
If you then know that some of the "stars" move around differently you might guess that they are far away or small objects.
You can calculate the distance between the Earth and the sun, but you can't fathom the depths of my scientific and mathematical ignorance.
“Other size and movement relationships could be worked out.”
But not by me.
"you can’t fathom the depths of my scientific and mathematical ignorance."
You sound proud of that. But then at the same time, you feel that you are qualified to criticize my points as "scholasticism"?
You do understand that, even when you ask for a "reliable source", you are saying that you have the ability to decide what is and isn't? At the same time you are poor-mouthing your own abilities?
Why don't you put aside your insecurity and resentment and try to advance your understanding. It does require taking the chance on being wrong, as Greg and I have done in our exchange, and being grateful for what is learned.
No, not proud, but unlike you aware of my limitations. Based on what you've written here, I'd bet that you are totally devoid of self-irony, and totally lack the ability to laugh at yourself.
And unlike you I generally know not to make authoritative pronouncements when I'm not qualified to do so. An example from your comment #32:
“So, why are we we still enabling the misconception fostered by the Denialists that GMST is exclusively probative, and that the energy balance is open to question? Do we still doubt our own basic physics?”
If you had addressed that comment to me, I wouldn't have been as kind as Greg was. It's a clear indication of how little you know and how much you think you know. Pure Dunning Kruger.
Do I have the ability to distinguish between reliable and unreliable sources? Regarding climate change, yes. And it's a sign of your dishonesty that you try post festum to excuse your inability to produce any source by questioning my ability to make that determination.
“Why don’t you put aside your insecurity and resentment and try to advance your understanding.”
In other words, advancing my understanding means submitting to your higher wisdom. As I wrote before, “I see you as someone with a very inflated opinion of himself.” It doesn't help that your superiority complex is here couched in pompous, sanctimonious pontificating. In case you didn't know, a superiority complex is deeply entwined with an inferiority complex, and your reference to insecurity and resentment seems to be about you.
I have no desire to continue this discussion.