Arguments
Are surface temperature records reliable?
What the science says...
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The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers. |
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Climate Myth...
Temp record is unreliable
"We found [U.S. weather] stations located next to the exhaust fans of air conditioning units, surrounded by asphalt parking lots and roads, on blistering-hot rooftops, and near sidewalks and buildings that absorb and radiate heat. We found 68 stations located at wastewater treatment plants, where the process of waste digestion causes temperatures to be higher than in surrounding areas.
In fact, we found that 89 percent of the stations – nearly 9 of every 10 – fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/reflecting heat source." (Watts 2009)
Temperature data is essential for predicting the weather. So, the U.S. National Weather Service, and every other weather service around the world, wants temperatures to be measured as accurately as possible.
To understand climate change we also need to be sure we can trust historical measurements. A group called the International Surface Temperature Initiative is dedicated to making global land temperature data available in a transparent manner.
Surface temperature measurements are collected from about 30,000 stations around the world (Rennie et al. 2014). About 7000 of these have long, consistent monthly records (Fig. 1). As technology gets better, stations are updated with newer equipment. When equipment is updated or stations are moved, the new data is compared to the old record to be sure measurements are consistent over time.
Figure 1. Station locations with at least 1 month of data in the monthly Global Historical Climatology Network (GHCN-M). This set of 7280 stations are used in the global land surface databank. (Rennie et al. 2014)
In 2009 some people worried that weather stations placed in poor locations could make the temperature record unreliable. Scientists at the National Climatic Data Center took those critics seriously and did a careful study of the possible problem. Their article "On the reliability of the U.S. surface temperature record" (Menne et al. 2010) had a surprising conclusion. The temperatures from stations that critics claimed were "poorly sited" actually showed slightly cooler maximum daily temperatures compared to the average.
In 2010 Dr. Richard Muller criticized the "hockey stick" graph and decided to do his own temperature analysis. He organized a group called Berkeley Earth to do an independent study of the temperature record. They specifically wanted to answer the question is "the temperature rise on land improperly affected by the four key biases (station quality, homogenization, urban heat island, and station selection)?" Their conclusion was NO. None of those factors bias the temperature record. The Berkeley conclusions about the urban heat effect were nicely explained by Andy Skuce in an SkS post in 2011. Figure 2 shows that the U.S. network does not show differences between rural and urban sites.
Figure 2. Comparison of spatially gridded minimum temperatures for U.S. Historical Climatology Network (USHCN) data adjusted for time-of-day (TOB) only, and selected for rural or urban neighborhoods after homogenization to remove biases. (Hausfather et al. 2013)
Temperatures measured on land are only one part of understanding the climate. We track many indicators of climate change to get the big picture. All indicators point to the same conclusion: the global temperature is increasing.
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See also
Understanding adjustments to temperature data, Zeke Hausfather
Explainer: How data adjustments affect global temperature records, Zeke Hausfather
Time-of-observation Bias, John Hartz
Check original data
All the Berkeley Earth data and analyses are available online at http://berkeleyearth.org/data/.
Plot your own temperature trends with Kevin's calculator.
Or plot the differences with rural, urban, or selected regions with another calculator by Kevin.
NASA GISS Surface Temperature Analysis (GISSTEMP) describes how NASA handles the urban heat effect and links to current data.
NOAA Global Historical Climate Network (GHCN) Daily. GHCN-Daily contains records from over 100,000 stations in 180 countries and territories.
Last updated on 15 August 2017 by Sarah. View Archives
Have a question. In 1981, Hansen published a paper which includes a mean average, the baseline global surface temp, of 288 Kelvin (14.85 degrees celsius or roughly 59 degrees Farenheit) for the years 1950-1980. He testified before Congress that 3 of the hottest years were in the 80s and also stated 59 degrees was the average from 1950-1980.
Jones stated 6 of the hottest years up that point were in the 80s and listed them in 1988 and also stated that the average from 1950-1980 was "roughly 59 degrees." Of course, in the 90s, same message of more hottest years and same with the 2000s.
However, we have not seen one single year since those comments and warnings were made where the average global surface temperature exceeded 59 degrees. Just hasn't happened.
So what's up with that?
[PS] Potentially response to this topic.
Randman @451, I have replied to you on this thread, because your concern seems to be more with the reliability/accuracy of surface temperature records, rather than with the ancient "predictions" made by Hansen last century.
And probably best if you stick with "standard degrees" instead of "Fahrenheit degrees" (Fahrenheit being rather 18th Century!) .
World temperature has risen approx 1.0 degrees since the pre-industrial age [the time of Fahrenheit himself!!!] . This rise is the average of local regional rises worldwide (this being far more useful and precise way of looking at the facts, rather than the vague/diffuse and somewhat unhelpful "world's average temperature").
Yes, the Arctic rise [i.e. local anomaly rise] is much higher than the "averaged" anomaly rise of 1.0 degrees — but it does not contribute much to the total anomaly, because the Arctic area is only a small fraction of total global surface area. Nevertheless, the Arctic rise is disproportionately highly important, because of its effect on ice-melting / ocean currents / Northern Hemisphere weather events / and feedback on global warming.
Randman, you will notice that the different organizations (such as NASA, and NOAA, and the Japanese Meteorological Organisation, etc) have a preference for comparing the very latest temperatures against a variety of baselines e.g. 1950-1980 or 1970-2000 or the full 20th Century etcetera. And this makes life unnecessarily complex for non-specialists [i.e. you and me].
But I am sure you appreciate, Randman, that whatever the baselines of of reference, the world is getting much warmer and doing it very quickly (whether things are expressed in degrees Celsius / Fahrenheit / Reaumur / or whatever). Whichever labels are used and whatever human yakking goes on . . . yet the real physical world shows strong evidence of rapid warming — wherever you look! Vasts amounts of polar ice are melting; sea levels are rising ever faster; glaciers are disappearing; and plants & animals are changing their activities accordingly.
To that extent, Hansen's various projections [scenarios] of future temperature are little more than of interest to historians. Yes, they're broadly far more accurate than those of science-deniers such as Lindzen . . . but nowadays we've had nearly 30 more years of experience in seeing the reality of the "Hockey Stick" rise in global temperatures. By whichever 30 / 50 / 100 year baseline you use, the recent years of 2014 / 2015 / 2016 / and so far in 2017, have been the hottest on record i.e since around 1880 (or by proxy measurement, the hottest in the past 2000+ years).
So, global warming is pressing ahead at high speed (in geological terms). And no sign of slowing down anytime in our near future.
btw, Randman, in your post you mentioned Hansen (who is famous enough in scientific circles to be referred to as just a single name — rather like Cher and Beyonce in pop music circles!). But who is the "Jones" you mention? Presumably not the Tom Jones of yesteryear!!
Eclectic @452,
Indeed, the missing Randman reference @451 would not be Tom but Phil Jones (no relation) who's phone interview became part of a 1989 NYT article titled "Global Warmth In '88 Is Found To Set a Record".
Eclectic, still learning to use this forum. Phil Jones (English pioneer of some note for global warming scenarious, etc,...) is the Jones I referred to, as someone else stated.
In an effort to simplify, will repeat myself a little. The consensus was that the mean from 1950-1980 was 15 degrees celsius. The prediction and warning had to do with rapid increases ABOVE 15 degrees celsius. That never happened and so no, I can't agree the planet has warmed.
No matter how many graphs, claims, adjustments, etc,.....that purport to show increases in mean global temps, unless there is a good, peer-reviewed series of papars, or at least published and discussed widely with skeptics not shouted down, it's unreasonable to accept as necessarily valid claims of warming.
Where's the beef here? I am open to why the mean from 1950-1980 was lowered retroactively from 15 degrees celsius to 14 degrees celsius but hope you can understand my skepticism. You have a group who forcefully argues a near doomsday scenario requiring massive global regulatory changes with very specific and bold predictions, and they don't happen. No years above the mean, and then the mean is lowered?
What is the basis for lowering the mean? The science behind it? Are there published papers dealing with that? Were skeptics allowed to offer pubished rebuttals? Or is this more a matter of faith?
Eclectic, concerning some other comments on evidence: take, for example, the claims of sea level rise. Frequently, sea levels rising in a location due to the land subsiding are credited to climate change such as the case of south Florida. But the truth is they are pumping the aquifier, have dammed up and filled in wetlands and so it's clear the sea has risen rather than the land subsiding, and yet flooding is credited to climate change.
On the other hand and this is anecdotal, there is a town built in the 1500s by the Portugese where the sea walls were precisely designed to flood once per month with the highest tide. There appears to be no rise or change in sea level there in several hundreds years. I know it's anecdotal but still. We have a hard physical record of no change.
In Florida, when I was a boy you could grow orange groves in north Florida. There is a town called Orange Park, in fact. In colonial times, you could grow oranges in South Carolina: hence a town called Orangeburg. Over the few hundred years, beginning long before industrialization, the freeze line has crept further south such that now orange groves freeze at those latitudes.
So yes, that is climate change but it's not evidnece of global warming (got colder, not warme). Nor is it evidence of industrialization and production of CO2 causing this.
During the MWP and Little Ice Age, we saw much more rapid climate change prior to industrialization. Jones finally admitted that the MWP could have been global. The proponents of AGW had handwaived the MWP away insisting it was just confined to the northern hemisphere.
Some of the glaciers that melted and presumably back to prior to man's settlements, actually showed settlements underneath. The truth is none of these things are unprecedented. Back in the 30s, there were numerous published reports of the arctic melting and warnings of sea level rise but it didn't happen. There were just some very warm years around that time.
So this claim of high speed climate change is simply incorrect. We've seen much higher change in human history already.
[JH] If your false statement about about Orangeburg, SC is indicative, your entire post may be nothing more than a fabrication.
From Wikepedia...
Meant to write, it's clear the sea is "not" rising. Don't see an edit button. Apologize for that.
Randman, I have to wonder what you use for sources. So far, the worst freezing impact event I have found for Florida citrus growers was the great freeze of 1894-95. There has not been an impact freeze event since 1989. The northern and central portion of the state saw some snow back in 2010. Snow is reported as far back as records exist, 1774. I'm quite skeptical of your Florida claims.
Philippe, not sure what you asking here. My comments are based on observation. It's a fact that you can't really grow oranges in the Jacksonville, FL are anymore, at least not commercially. I base that on having lived there, had an orange tree in the yard, noted how oranges don't grow or turn sour if grafted, and on the fact when I was a yojng boy travelling to Florida, there were tons of orange groves in areas that can't grow there now.
If you want, look up the zones for growing things, and you can see this for yourself. Orange groves had to move south. This shouldn't be a controversial comment as it's demonstrably true.
In colonial times, you could grow oranges in South Carolinal which is why a town was named Orangeburg.
If you want sources, google the towns of Orangeburg and Orange Park, and you can verify they do exist. You can also look up the times when orange groves would grow there if you'd like.
Here's a timeline of significant freezes.
"The *impact freeze that occurred on February 2-9 brought the lowest temperatures that had ever been recorded in north and central Florida. This freeze is considered an *impact freeze because it ended attempts to commercially grow citrus in South Georgia, southeast South Carolina and in the northern part of Florida."
http://flcitrusmutual.com/render.aspx?p=/industry-issues/weather/freeze_timeline.aspx
Note this comment elsewhere as well:
"he century preceding the damaging freeze of 1835 was relatively warm as evidenced by the fact that unprotected orange trees were grown and reached full size in South Carolina and Georgia (Attaway, 1997). Freezes that caused injury to citrus as far south as central and southern Florida occurred in 1835, 1857, 1894, 1895, 1962, 1981, 1982, 1983, 1985, and 1989. In Alabama during the first half of the 1900s (1900 to 1948), severe freezes that injured satsumas occurred in 1924, 1928, 1930, 1933, and 1940 (Winberg, 1948b)."
http://hortsci.ashspublications.org/content/43/2/287.full
This region grew colder, not warmer. Also note, there are different kinds of citrus. Satsuma, which the paper discusses, can withstand colder temps from what I understand.
randman @454.
You state "The consensus was that the mean from 1950-1980 was 15 degrees celsius." Where do you get this from?
All I see is a newspaper article from early 1989 (see link @452) that quotes PD Jones saying:-
While 59ºF = 15ºC, I don't see this statement in a newspaper article about a 1950-79 anomaly-base obtained as part of a telephone interview as constituting any sort of past "consensus."
If you calculate the average anomaly from today's HadCRUT4 for this period 1950-79, it comes out to -0.065ºC. And just to join all the dots up, the HadCRUT4 anomaly for 1988 is +0.199ºC, yielding a 1950-79-based 1988 anomaly of +0.264ºC. While this is significantly lower than the "0.612 degrees Fahrenheit" quoted in the article (= +0.34ºC), it must be born in mind that the coverage of global temperature data was still being developed back in the late 1980s as Jones (1988) rather well ilustrates.
MA Rodger, look it up if you don't believe me. Hansen's 1981 paper has the mean from 1950-1980 at 288 LINK
In 1988, he testified it was 59 degrees F. Same thing basically.
LINK
Jones also said it was 59 degrees which is the same as 15 degrees celsius.
Where are the papers to justify revising it MUCH LOWER to 14 degrees? Just looks very arbitrary to me and after the predictions of higher annual means over 15 degrees failed to materialize.
If you disagree, show me something from 1988 or earlier, meaning that was written and published then.
[RH] Shortened links.
[JH] The use of all caps constitutes shouting and is prohibited by the SkS Comments Policy. Please read this policy and adhere to it.
Randman, you have an interesting way of thinking.
On the basis of (A) one alleged sea wall in Portugal, and (B) whether oranges can be grown in northern Florida versus southern Florida . . . you entirely dismiss a century's accumulated evidence of substantial rapid global warming. (Including your handwaving away of the latest 4 decades of satellite evidence of ongoing accelerating sea level rise / spectacular attrition of glaciers / and the melting of thousands of cubic miles of ice.)
Quite marvellously amusing, Randman. Clearly you possess a peculiar & intense sense of humor.
Though in view of the seriousness of the global situation, your humor counts as black humor. Or is orange the new black?
Eclectic, can you just stick to the facts? You say there is all this evidence. I have been looking at the presentations of that "evidence" for 30 years and frankly, doesn't appear to be any evidence at all to speak of.
That's why I asked about the mean of 59 degrees, 15 degrees celsius. I was hoping someone here on a site dedicated, it appears, to discounting skeptic arguments of AGW, would be able to offer their explanation of why the mean was retroactively changed. Just read a few peer-review papers from the 80s which boldly talk of deviations from the mean in great detail. But noticeably absent is a discussion of the actual base-line. Seems like you have to search high and low for that.
Hansen's 1981 paper does include his baseline as well as various comments from he and Jones to the press and testimony before Congress.
But at some point, 15 became 14, and I can't find a single scientific paper explaining why that was. Now maybe you don't see the significance of that? But if the mean from 1950-1980 was 15 degrees celsius, we have seen no warming whatsoever in 30 years, and whatever else has happened could not have been caused by warming because it didn't happen.
So I ask again. What was the justification or reason for lowering the baseline from 15 degrees celsius to 14 degrees celsius. If you don't know, that's fine, but don't act like it's some kidn of crazy question.
Eclectic also, perhaps the point on oranges went over your head? We're talking around several hundred years of significant climate change for the Carolinas, Georgia and Florida where the region became colder, not warmer. This began long before industrialization and is a pretty significant climate change then that cannot be blamed on man causing it.
Particularly after the freeze of 1835, we saw a steady change pushing back commercial orange groves further and further south due to the region becoming colder, not warmer. That has yet to change, in fact.
Why is that if we are experiencing such unprecendented warming? What caused the climate change beginning in 1835 or actually earlier?
Randman: climatologists use anomalies instead of absolute temperatures, because the former can be estimated much more precisely. See the recent RealClimate post about that.
I am a little concerned about rebutting you on sea levels as not sure it's OK here to do that or not. But be that as it may, consider the following:
"The numbers didn’t add up. Even as Earth grew warmer and glaciers and ice sheets thawed, decades of satellite data seemed to show that the rate of sea-level rise was holding steady — or even declining.
Now, after puzzling over this discrepancy for years, scientists have identified its source: a problem with the calibration of a sensor on the first of several satellites launched to measure the height of the sea surface using radar. Adjusting the data to remove that error suggests that sea levels are indeed rising at faster rates each year."
http://www.nature.com/news/satellite-snafu-masked-true-sea-level-rise-for-decades-1.22312
1. The July 2017 report says the satellite data did not show sea level rise. My question to you is did you know that or were you led to believe prior to July that the satellite data showed sea levels rising? Be honest and ask yourself how that happened if "scientists" actually knew the data said something else.
2. Note the solution of adjusting the data. (Note to mods: this is why I think responding on this is appropriate on this thread because we are discussing the trustworthiness and reliability of data.)
If "adjusting the data" were just a one-off thing, this would appear unobjectionable perhaps. Would have to look at the technicals on the sensor stuff, but this seems like part of a pattern. Baseline in the 80s was 15 degrees celsius and then that's "adjusted" to 14 degrees which just happens then to show warming.
You don't find that suspicious, especially in light of the recent paper questioning such "adjustments" along with many scientists also questioning the adjustments with some of them having been much more pro-AGW.
I think there is an issue here and should be looked into. Are we merely being sold a story based on adjusting data to fit a narrative?
Tom, I understand that but anomalies are based on differences from a baseline. So the mean is critical to whether warming or cooling or nothing much has occured. If you just change the prior baseline one whole degree celsius from 15 to 14, the picture of recent anomalies greatly changes, right? But unless that change is accurate, that picture of anomalies means very little in terms of reality.
No, randman. You are confusing terms and concepts. "Baseline" used for computing an anomaly for one particular temperature station is the average temperature across the baseline period as measured at just that one particular station. The same is done for each of the other stations. The anomaly in each geographic grid cell is the average of those anomalies. The global anomaly is the average of those grid anomalies. Never in that process is the global absolute temperature computed. I was confused by your use of the term "baseline" To mean global absolute temperature.
Ok, let's use the term "mean" as Hansen does here when he says the mean surface termperature is 288k.
LINK
How is it in the 80s, the consensus, it appears, is the mean from 1950-1980 was roughly 15 degrees celsius, and then later that was changed to 14 degrees celsius? What the mean "for one particular station" isn't what we're discussing but changing the mean from a 30 year period from 15 to 14, which of course shows a very different picture in terms of anamolies, right?
When you read these papers with graphs showing such and such anomaly, they are discussing more than one weather station with a baseline which is 0. That's why I used the term, baseline.
[RH] Shortened link.
Tom reading your comment again and more closely, the thought comes to mind then that the only way to lower the global mean is to say the temperature readings in the past which previously said such and such, were changed, right?
Otherwise, there'd be no revision lower from 15 to 14. If the 15 degrees was based on an average of temp readings, and of course looking at the different regional placement of such weather stations and distances, well if you assume they used decent basic analysis in the 80s for the data, how in the world did the data change?
Randman @466 , your referenced Nature news article (itself citing Dieng, Cazenave, Meyssignac & Ablain 2017, in Geophysical Research Letters) confirms an accelerated rising sea level globally. The satellite data is also in accord with the longstanding worldwide tidal gauge data.
And yet you come out with your complete fantasy that the observed long-term sea level rise worldwide has halted or even reversed [which would require 100's of cubic miles of "re-freezing" to occur in quick order — and something of which there is zero evidence . . . except perhaps in Secret Government Mega-Freezers buried under the Florida swamps & guarded by gators].
Do you not understand that the world's ice is melting because conditions are getting warmer? And that the melting is happening — regardless of the presence of any calibrated thermometer within a 10,000 mile radius.
In effect, Randman, you are stating that all the well-correlated data globally has been manipulated in a century of Giant Worldwide Conspiracy. More black humor from you, Randman?
Eclectic, why don't you discuss the questions and facts I posed to you? I think they are very clear. The paper states the satellite data did not show sea level rise, right? That just this July they found a "solution" that would show it by adjusting the data.
Now, how long have you believed the satellite data showed sea level rise? Since late July or earlier? Please answer the question.
Randman, your answer is in the RealClimate post I linked for you. Actually read it this time, please.
Tom, come on. Let's talk honestly. Of course I get the concept of looking at the changes rather than absolute data (although the absolute data should be shown, imho).
The issue is they were doing that when they said the data showed 15 degrees was the mean over the time period from 1950-1980.
Do you get that?
Why was the mean subsequently adjusted to 14 degrees celsius? If you look at the data based on the prior mean, aggregated I assume from many data points, then we have had no warming. It's pretty simple. There's no way looking at the changes can make 14 degrees equal 15 degrees, right?
There wasn't new data for "reanlysis" as far as I can tell that applied to the period prior to 1979. What you have are assumptions or hopes or professional stances linked to one's career that call for reinterpreting very basic data. The readings people took did not change.
Randman, you are missing the part of that post that answers your question. It explains and demonstrates the large variability in estimates of absolute temperature. Whichever estimate of absolute temperature from the 1980s that you are fixated on was not the only estimate then and certainly is not the only estimate now. Stop typing long enough to really read that article.
Tom, I will try to make this simple. The only constant I see is claiming every decade we see a number of the warmest years. It's their MO.
Hansen published in a peer-reviewed article that 4 of the warmest years on record were in the 80s. I can show you that if you don't believe me. Then when challenged on 1998 being the warmest year, to make a long story short, he moderates and says 1998 was tied with 1934 as the warmest year.
Wait, what happened to the 4 years in the 80s that were supposedly warmer than 1934?
At some point, you gotta say this looks like some bigtime bs. The only consistent thing is the scare-mongering and claims a number of the past 10 years are the warmest ever and pretty soon NYC will be under water or some such.
Pretty soon it will be 2018 and none of the predictions will have come true but we will still hear the same based on "adjustments" to the data selling the same narrative.
[DB] Multiple instances of off-topic, sloganeering and inflammatory snipped.
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Randman, it appears you have also not read the Nature news article (with its linked scientific paper by Dieng et al, 2017) which demonstrates the opposite of what you said. A scientific source which you yourself referenced. Or perhaps you did read that, and chose to brazenly misrepresent the sea level information.
Randman, your credibility is zero — though you do score points for black humor and/or orange-haired chutzpah in your promotion of Alternative Facts.
But you go too far, Randman. For even the Chief of Alternative Facts knows that more ice melts as conditions get warmer.
randman @461.
I am struggling to keep up with your wild pronouncements.
You claim that "Hansen's 1981 paper has the mean from 1950-1980 at 288" with a link to Hansen et al (1981) which says no such thing. It does say "The mean surface temperature is Ts ~288K" but this is not associated with any global average temperature measurements or the period 1950-80. Instead, it is presented to illustrate the power of the greenhouse effect on climate.
And the second piece of evidence you provide is another NYT article, this one from 1988 which tells us "How hot is the world now? The scientists do not offer a straightforward response, saying that the vast amount of data is still being studied and that comparisons cannot be precise." It is in this context that the article offers an average global temperature from Hansen:-
I would suggest the 59ºF being quoted in both the 1988 and 1989 NYT articles results from a journalist insisting on obtaining an average temperature to better inform his readers, a value reluctantly provided by his interviewees. It is certainly no indication of any "consensus" and your insistence that there has been a revision of the temperature record remains entirely unfounded.
May I also correct some of your confusion @476.
You describe "the 4 years in the 80s that were supposedly warmer than 1934," the four 80s years being "4 of the warmest years on record were in the 80s" apparently set out in a peer-reviewed article by Hansen. Without sight of that article, I note in yet another 1988 NYT article it is stated that "Dr. Hansen ... had previously reported that four of the hottest years on record occurred in the 1980's." So of the years 1980-87, Hansen had reported that four of these years exceeded all pre-1980 anomalies. Where have they gone? A quick glance at GISTEMP LOTI shows they (1987, 81, 83, 80) are still there.
As for 1934, all 1980s years are warmer than 1934 by some considerable degree. However there has been a bit of a kerfuffle involving 1934 it being for some years (and may still be for all I know) the hottest year on record in the "contiguous states."
randman,
I don't often comment here, but thought I would this time since I may be able to answer your question on the change in global mean temperature for 1951-1980.
I suspect that you're mistaken about what paper Hansen used to get that value. I suspect it actually came from Hansen and Lebedeff, 1987. (There's also an updated version of that paper from 1988, but I can't find a copy of it and it just seems to include the data through 1987, so it probably doesn't change anything.) If you look at Figure 1 in that paper, you'll notice that the paper is missing a lot of data from the oceans. More recent attempts to find global temperatures has included ocean temperatures as well, and I believe that will tend to lower the global temperature values overall. (See also Victor Venema's blog about station data homogenization. You might read some of the articles on Victor's blog - they may answer some of your questions.)
I don't think it's particularly surprising to find that, as time moves on, science has found better answers to questions - that is, after all, kind of the point of science.
[TD] I fixed the links. You can't type HTML to enter a link. You must click the Insert tab and then the link button. I deleted your followup with the now-redundant links.
randman: You are Gish Galloping. You complained about absolute temperature estimates changing, but you were mixing terms and concepts. Several people gave you information that answered your question and (should have) cleared your confusion.
Then you were complaining about supposed changes in estimates of temperature changes. Scientists do not measure changes in temperature by differencing one year's absolute global temperature from an earlier year's absolute global temperature. Instead they difference anomalies. After that was explained to you several times you insisted that you fully understood that.
Now you are complaining about supposed changes in relative temperatures. Again. But you are acting as if you have been discussing the same topic all along, and that I am an idiot for not recognizing that. No. You have been changing topics. Several people have been trying to give you the answers you are asking for, but you are a moving target.
Tom, where have you explained how the consensus mean from 1950-1980 was considered to be 15 degrees celsius and later changed to 14 degrees celsius?
Nothing you've "explained" explains that. This has signifant ramifications because if the mean was 15 degrees, we've experienced no warming the past 30 years and the whole thing crashes like a house of cards. It'd be like amassing all this evidence someone committed a murder but then the guy supposedly murdered shows up alive. That "evidence" is then moot.
Now you can talk about comparing changes in individual weather stations and amassing those averages and differences all you want or any other technique but that's a separate question. Could be they changed how they do that? Could be they just arbitrarily lowered everything en-masse? Could be the adjustment to 14 degrees is totally honest and the same standards are applied to recent temperatures as to those such that if we went with the old standards, we'd have global means higher than 15 degrees celsius?
But where are the peer-reviewed papers discussing why the mean was lowered, which coincidentally makes the past 30 years look warmer relative to that mean?
[DB] Blatant lies snipped.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive, off-topic posts or intentionally misleading comments and graphics or simply make things up (i.e., blatantly lie). We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter, as no further warnings shall be given.
Steve, thanks for answering or trying to. Will look at those papers and blog on the oceans. However, not precisely sure estimating past oceanic readings to lower the mean is necessarily valid. At a minimum, it should be a reasonable discussion and debate. We, in the public, are being asked to use governmental power to make wide-raning changes, and yet what appears to me as the answer to reasonable questions is often just to shout people down and call them deniers. Moreover, it really looks very fishy. Bold predictions were made that didn't come true and then the mean in the past is lowered, which coincidentally props up the theory as well as the flow of funding?
Btw, the reference ot 288 Kelvin is from 1981 but will look at the papers you mentioned as well.
[PS] Sloganeering removed.
So far your participation on this forum shows you asking reasonable questions based on a misreading of media reporting, misunderstanding of how temperature series are constructed and now misunderstandings of how and why adjustments are made. Furthermore you "reasonable" questions would seem to suggest that you have uncritically accepted misinformaton from denialist sources. Just because you misunderstand something does not make it wrong.
If you wish to participate here can I suggest the following:
A/ Consider the possibility that your understanding of the science may be wrong and misinformed. People here are trying to fix that but it behoves on you to put reasonable effort into understanding the explanation and reading resources provided. Clinging to misinformation because it suits your beliefs is the heart and soul of denial and you dont want to be accused of that do you?
B/ Cite your sources. Do not make statement without saying what informs your opinion preferably with link or at least a proper cite. Hansen 81 is barely good enough - a title it much better.
C/ If you wish to claim science is wrong, then first cite the reference where science makes the claim you dispute. (Straw man claims are the heart of denialist blogs). Then cite the evidence which you think disproves the claim. Doing this will get reasonable responses from people here.
Any further sloganeering will simply result in comments being deleted. The comments policy here is not optional.
Steve, if interested, this the 1981 paper with 288 Kelvin as the 1950-1980 average.
LINK
[RH] Can I request that you learn how to use the embed function for links? Some long links break our page formatting. It's quite easy to create a short description or title and then embed the link into the text. Thx.
Tom, this is the paper by Hansen with 288 Kelvin as the mean. I think you've already seen the press comments by Hansen and Jones in 1988 of 59 degrees F and "roughly 59 degrees" respectively, right?
LINK
Obviously regardless of looking at anomalies, there is a reason they believed the mean was 59 degrees. The fact climatologists like to look at anomalies does not change that, does it? Not seeing your point.
On a wider note, this appears to be a pattern. 15 degrees was later adjusted down to 14 degrees, which had the effect of making the then present temps appear warmer, whether correctly so or not.
More recently, we've seen satellite data that showed no sea level rise to speak of "adjusted", perhaps correctly so or not, to now show sea level rise.
http://www.nature.com/news/satellite-snafu-masked-true-sea-level-rise-for-decades-1.22312
Prior to that we saw the posited warming hiatus changed by some, which changes including lowering the past means among other things. One climatologists somewhat famously has complained about this, Judith Curry. Some of her comments here:
""This short paper in Science is not adequate to explain and explore the very large changes that have been made to the NOAA data set," she wrote. "The global surface temperature data sets are clearly a moving target. So while I'm sure this latest analysis from NOAA will be regarded as politically useful for the Obama Administration, I don't regard it as a particularly useful contribution to our scientific understanding of what is going on.""
http://news.nationalgeographic.com/2015/06/150604-hiatus-climate-warming-temperature-denier-NOAA/
https://judithcurry.com/2015/07/09/recent-hiatus-caused-by-decadal-shift-in-indo-pacific-heating-2/
As I understand it, Curry was a proponent of AGW and perhaps still is in some respect, but has had problems with the way the data has been adjusted and the accuracy of the models among other things.
She's not the only scientist raises these questions. So it's not just laymen like myself who wonder why there appears to be a pattern of data that does not line up with predictions simply being "adjusted." These adjustments are not just one-off things either but a fairly consistent feature here.
[DB] Blatant lie snipped. Sloganeering snipped.
[PS] "Obviously regardless of looking at anomalies, there is a reason they believed the mean was 59 degrees. "
And just as obviously, you still have not understood that anomaly measurements do not reference a global absolute temperature. Until you bothered to study and understand this, you cannot make progress. Read the material provided.
[RH] Shortened link.
These are quotes from this particular site on how to understand calculations of anomalies.
" The World Meteorological Organisation (WMO) defines Climate as the average of Weather over a 30 year period. So if we look at a location averaged over something like a 30 year period and compare the same location averaged over a different 30 year period, the difference between the two is how much the average temperature for that location has changed. And what we find is that they don’t change by very much at all.
....
Rather than averaging all our stations together, instead we start out by looking at each station separately. We calculate its long term average over some suitable reference period. Then we recalculate every reading for that station as a difference from that reference period average. We are comparing every reading from that station against its own long term average. "
So comparing individual station's data "against its own long term average", which means calculating the long-term, maybe 30 year term average is critical to assessing the difference between measurements against that average.
Not very complicated.
As I stated on other posts, the mean in Hensen's paper for 1950-1980 globally was very close to 15 degrees, and in 1988 he said the mean was 15 degrees and Jones in 1988 said "roughly 15 degrees." Those are facts of what was stated and reported, whether correctly or not.
Some here have accussed me of not understanding the calculations of anomalies. Of course, individual stations are not compared to the global mean. Some areas are warmer or colder than others, for example. That would be ridiculous.
However, statements of, for example, the warmest year ever are not based on mere consideration of a single or a few stations but on an aggregate of all the data, which would include either all stations or a sufficient spread of them to make a reasonable calculation.
It is doubftul Hansen and Jones just made up the number of 59 degrees or 15 degrees celsius. Hope not at least. Hansen was testifying before Congress and arguing global warming was a very serious issue.
One must assume they based their view of the mean from 1950-1980 on actual data, right? They were looking at changes in the temperature record at each individual station and analyzing that. Since then, we see the global mean surface temp announced with claims of one year being warmer than another and so forth.
So if based on studying this data, the claim was the mean from 1950-1980 was 15 degrees celsius, can someone please show the peer-reviewed papers justifying lowering it to 14 degrees? Just asking that once again. Only one person has even tried to answer by suggesting some possibilities, linking to a blog to look further, and yet to me, I would think this is something proponents would have on-hand. I mean, of course, there should be an explanation of such a large shift on the view of what the data indicated, right?
[PS] The whole point of anomaly method is that absolute temperature average is very difficult to measure with any precision (and is dubious as to whether it is meaningful number in any actual application), whereas change in the anomaly can be measured with considerable confidence. Hansen's number of 15 degree is really a rough estimate.
As far as I can tell, nobody gets where you have inferred that temperature average has somehow been lowered and you seem to implying nefarious adjustment from this. If you understand that trends are change in anomaly from some baseline, then why are going on about absolute temperature? it is meaningless in this context.
In response to the mod, I am merely asking for the peer-reviewed papers that show the adjustment. If you are requiring something stating 14 degrees celsius at present, I an easily do that. If you are saying that's meaningless, c by the way, to compare current global surface temps in claims of the hottest year and so forth, something we see a lot of?
What's with the press reports stating 2016 was the hottest year, for example, if that's such a dubious claim to begin with? Only way to argue it was the hottest year, as just an example of what I am talking of, is to have an idea what the prior year's were. So if you start saying the mean from 1950-1980 was roughly 15 degrees celsius and then have numerous years you state are less than 15 degrees celsius, obviously you no longer consider the mean from 1950-1980 to be correct, right?
I am not understanding your grievance here. All I am asking for is how that determination to revise downward the mean happened. Where are the papers showing that? Is your position none are needed?
[PS] There is no adjustment. We are trying to understand why you think there is one. Where do you get the idea that absolute temperature is now 14 and was 15 in past? In what context do you see absolute temperature being stated and used? You claim a certain year is hottest because the anomaly has changed x degrees from baseline. The baseline defines zero. There is no need to know what that is in absolute terms. Look at the graphs of various temperature series in the article. They never report a temp. Only the change of the average of the anomalies.
Our "grievance" is struggling to understand how you have your wires so badly crossed about something that is fairly simple. A temperature station doesnt report that average temperature in 2000 is say 17. It reports that is say 0.8 degrees higher than whatever the average of that stations temperatures was from 1950-1980. Spatially average all those differences from all the stations worldwide and you have the number plotted on all those graphs above.
randman, you wrote
Correct. But then you implicitly made an incorrect conceptual leap. You incorrectly assumed that the "aggregate of all the data" is the global mean absolute temperature. It is not. The data being aggregated are the anomalies. Therefore the aggregate of those anomalies is the global mean anomaly temperature. Not the absolute temperature. The absolute temperature for the globe never is calculated in that procedure. Even the absolute temperatures for each of the individual stations disappear from the data as soon as the individual anomalies are calculated.
Estimating the mean absolute temperature of the globe cannot be done to any useful precision or accuracy simply by averaging the absolute temperatures of all the individual stations. The operations for doing it instead are very complex, require much more information and assumptions, and inevitably yield an estimate that is an order of magnitude (that's 10 times--move the decimal point to the right by one digit) less certain than an estimate of global mean anomaly. Changing any of that can yield a very different global mean absolute temperature even if 100% of the individual absolute temperature measurements are not changed.
People have been attempting to estimate global mean absolute temperature since at least Fourier's calculation in the 1820s, which allowed him to realize that the atmosphere was insulating the Earth. There have been, and ongoing continue to be, many estimates, and they have and continue to vary between each other, even when they use exactly the same temperature measurements as inputs. So your claim that "the" estimate of the mean global absolute temperature was changed from 15 to 14 degrees Farenheit, is wrong. There never has been a robust consensus on absolute global mean temperature at high precision nor high accuracy. If you really were interested in absolute temperature, you would have surveyed the considerable literature.
But you did not. Your citation of the Hansen et al. paper for your 15 degree claim is inappropriate. I believe global mean absolute temperature was mentioned in that paper only once, was only approximate ("~288"), and was mentioned only in passing as context for the rudimentary and obligatory background introduction about the laws of radiation and so on. That paper did not in any way address the precise value, and the authors did not in that paper describe any of their work to attempt to determine that value, because that paper instead described only their work to estimate the trend with anomalies. I would be shocked if estimates of absolute temperature have not changed over the decades, because climatologists have continued to attempt to improve their estimates. But not for the purpose of better estimating the trend of global temperature change.
The mean absolute temperature of the globe could be re-estimated to be 40 degrees colder or warmer without in any way affecting the mean anomaly of the globe. It's just arithmetic.
People interested in global warming are interested in the how fast the global mean temperature is increasing. That is the "trend" in the global mean temperature. The trend is the "slope" of the graph of temperature by time. The absolute temperature is irrelevant to the slope; changing it merely slides the curve up and down the y (temperature) axis, leaving the slope unchanged. Literally, unchanged. Because of arithmetic.
randman, you wrote "why is it published and stated and used, by the way, to compare current global surface temps in claims of the hottest year and so forth, something we see a lot of?" You are flatly, objectively, wrong. Absolute temperatures are not used in claims of the hottest year. Relative temperatures (anomalies) are used.
You wrote "Only way to argue it was the hottest year, as just an example of what I am talking of, is to have an idea what the prior year's were." Yes, you are correct. But the prior year's temperature need not be known as absolute temperature. The temperature relative to any baseline period's temperature is completely, perfectly, logically, mathematically, sufficient, as long as both this year and the prior year's anomalies are calculated from the same baseline time period.
So why would the Washington Post mention an absolute temperature and claim the NOAA does?
"The average temperature across the world’s land and ocean surfaces was 58.69 Fahrenheit, or 1.69 degrees above the 20th-century average of 57 degrees, NOAA declared. "
https://www.washingtonpost.com/news/energy-environment/wp/2017/01/18/u-s-scientists-officially-declare-2016-the-hottest-year-on-record-that-makes-three-in-a-row/?utm_term=.1a251a1f56ee
Note it is less than 59 degrees. So obviously if in the 80s people like Hanson and Jones believed the cumulative data indicated 59 degrees as the mean from 1950-1980, then there has been an adjustment in that data such that the NOAA can declare less than 59 degrees the hottest year ever since data has been collected.
Where is the explanation and peer-reviewed papers discussing that downward revision?
Tom you do realize the slope is pretty easily manipulated based on the time-frame involved among other things, right?
The bottom line are the comments of 59 degrees as a mean from 1950-1980 were not arbitrary. I am open to explanations from those involved as to why they were wrong. At the same time, adjusting the past temps down, excluding stations, adjusting temps from stations, etc,...make a very big difference in calculating anomalies, right? They are based on a mean of specific weather stations or measurement instruments.
So the question is if adjustments are made, why were they made? Are the same standards applied to the present measurements such that there is an honest account of relative changes. Just show the papers and data.
What's the problem here? You guys have a beef with someone like me watching this unfold for 30 years, hearing the mean was 59 degrees or 15 degrees celsius, and then seeing over and over again that such and such year was the warmest with an announcement of the mean for that year less than 15 degrees celsius?
Can't you see how any normal person would take that with a grain of salt. At least show me why and how you changed your view of the data in the past.
[DB] Blatant lie and inflammatory snipped.
Ok, just googled the NOAA and this just an illustration mind you and clicked on first or near thing that came up.
"Driven by record warmth in the West, the national average summer (June–August) temperature for the contiguous U.S. was 72.7°F, 1.3°F above average and the 15th warmest summer in the 123-year period of record."
https://www.ncei.noaa.gov/news/national-climate-201708
I don't propose there is anything controversial here. Just posting it to point out an absolute average temperature is mentioned here for the US and specified to be the 15th warmest year.
Now, I am sure I can look up other announcements from those keeping such records that mention absolute temps. This should not be controversial. It's not out of bounds to talk of things in this manner.
So why did Hansen and Jones think the mean from 1950-1980 was 15 degrees roughly and yet now it is considered to have been 14 degrees?
"The result of these calculations is an estimate of the global average temperature difference from a baseline period of 1951 to 1980.
"https://www.nasa.gov/press-release/nasa-noaa-data-show-2016-warmest-year-on-record-globally
So NASA stated their calculations are "an estimate of the global average temperature difference from a baseline period of 1951 to 1980."
"Baseline"? "Global average"?
Ah, now I understand. "Randman" sucked me in to his game. He can't be that stupid. He's just been jerking us around for his own amusement.
Please note the source of this:
"The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. The scheme was based on the finding that the correlation of temperature change was reasonably strong for stations separated by up to 1200 km, especially at middle and high latitudes. This fact proved sufficient to obtain useful estimates for global mean temperature changes.
Temperature analyses were carried out prior to 1980, notably those of Murray Mitchell, but most covered only 20-90°N latitudes. Our first published results (Hansen et al. 1981) showed that, contrary to impressions from northern latitudes, global cooling after 1940 was small, and there was net global warming of about 0.4°C between the 1880s and 1970s."
https://data.giss.nasa.gov/gistemp/
So NASA here points to the same 1981 paper I have brought up, which mentions a mean of 288 Kelvin which is 14.85 degrees celsius. They came up with number somehow. Talking of how the process involves individual stations does not change that. This is on their website. This is what they state.
Now it is clear that 14.85 degrees celsius or 15 degrees celsius which Hanson mentions 7 years later in 1988 is not still considered valid. Otherwise they wouldn't be saying annual means of less than that are hotter.
So despite bashing me for bringing this up, exactly how did they come up with the mean of roughly 15 degrees celsius and why has it been adjusted downward?
Tom Dayton @493 , ~ Quite so. Even the most intellectually-handicapped member of junior high school classes is capable of understanding the temperatures / anomalies / averages etc which Randman pretends to be confused by.
But there is a certain entertainment value in seeing the crazy gyrations of the Denialist mind which enjoys displaying itself in public. A subpontine dweller whose motivation must be at least 50% masochism.
______________________________
Randman @whatever ,
it's been a while since I last checked the NOAA website, and I thought you might be pleased to read this extract from their latest :-
"The global land and ocean surface temperature for the first eight months of the year ranked as the second highest in the 138-year record at 0.88 C (1.58 F) above the 20th century average of 14.0 C (57.3 F) — falling behind 2016 by 0.13 C (0.23 F), but ahead of 2015 by 0.03 C (0.05 F). Based on three simple scenarios, 2017 will likely end up as the third warmest year on record." (unquote)
Isn't that a beautiful wording, Randman.
The same 14.0 degrees that Hansen clairvoyantly predicted in his 1981 and/or 1988 speech, in order (in his kindly way) to show that he was intending to lower the world temperature (from 15.0) so that you would have some "grist for your mill". [ Literary note : though it is said that "the mills of God grind slowly" ~ yet the Divine mills grind never so slowly as the Randman mills. ]
But it seems, Randman, that you have a little problem — despite criticizing the world average temperature, you have not specified how you would like the average to be determined e.g. would you like regional temperatures to be summed up over all the 300 x 300 nautical mile squares constituting the Earth's surface. Or possibly 300 x 200 n.m. squares as you move away from the equator? Or the 300 x 100 n.m. squares as you get closer to the poles? Or something more Geodesic? Or less?
Or would you prefer, Randman, to use the 150 x 150 nautical mile squares ~ as used by NOAA or maybe NASA (or vice versa) ? I have a vague idea, Randman, that the (Japanese) JMO uses a somewhat different area measurement basis. Not to mention the Chinese system.
So which of these measuring systems is the one that you would choose, Randman? They all give a different result for World Absolute Temperature average. Randman, you are the One — you must choose for us (the red pill, or the blue pill, or some other color . . . in your case, perhaps the rainbow pill? . . . not that there's anything wrong with that! ) . Which method of averaging, Randman?
Oh if only the world were simpler, and we had a consensus of scientists to guide us in these matters!
Oh, er, yes . . . there is one more little problem with your way of "thinking", Randman. Since you have it somewhere in your head that all of the millions of scientists worldwide are (for decades now) in a Giant Conspiracy to lie to you and deceive your innocence . . . and that you know the Earth is cooling not warming . . . but then how is it that the ice is melting and the sea level has risen several inches since Hansen's pronunciamento in 1981 ? Just doesn't fit, does it? . . . unless WhatsUpWithThat and Judith Curry are wrong!
Puzzling, eh!
randman @494.
You ask of the global mean surface temperature: "why has it been adjusted downward?" The first step in answering that is to identify when it was adjusted downwards. You seem quite adamant that it had not yet been adjusted downwards in 1988.
With the preview version of Hansen & Lebedeff (1988) we can access the first page of this paper. This paper you argue is using the old 288K estimate for Ts and we can see the resulting global temperature record in Fig 1, from 1880 with an anomaly of -0.40ºC to 1987 with an anomaly of +0.33ºC.
Happily for us, the successor temperature record, NASA's GISTEMP LOTI, still uses the same 1951-1980 anomaly base. So by examining academic papers citing those LOTI anomalies, it will be easy-peasy lemon-squeezy to spot when this scurilous adjustment was carried out to pervert the climatical reocods of our planet. The adjustment will be very obvious as, with the adjusted anomaly base being calculated to have an average temperature 1ºC lower (14ºC instead of 15ºC), these global anomalies will be boosted upwards by +1ºC.
A quick look at the latest LOTI release we see that the 1880 anomaly has been adjusted from -0.40ºC to -0.20ºC and that the 1987 anomaly has been adjusted from +0.33ºC to +0.33ºC.
So when exactly was this GISTEMP LOTI adjustment performed?
MA Rodger, few things. First, how do we know the successor temp record still uses "the same 1951-1980" base, and what is that base specifically in abolute temps?
Second, Hansen is a co-author of the 1988 paper you bring up, right? Same year he testified that the 1950-1980 mean was 59 degrees F. Are you suggesting he wrote one thing in his scientific journals and said something different before Congress or what?
[DB] "Same year he testified that the 1950-1980 mean was 59 degrees F"
Source citation, please.
Sloganeering snipped.
Eclectic, so you admit the 14 degrees mean is something they calculate? Finally, and yet you pretend I am the ignorant one here?
So we saw in 1981 and in 1988, the mean was 15 degrees, at least for the 1950-1980 base. Now it is 14 degrees. Let's keep this simple and straightforward. How they come up with that isn't really a concern at this stage in the conversation. First, we need an agreement on very basic facts.
If you won't even admit something was stated, it's kind of silly to get into why and how they came up with the idea, and it seems as if you are trying to suggest something isn't factual and then demand an answer on the details of how such facts should be measured.
First, let's admit what is factual in terms of the statements and historical views here.
Also, I noted your quoted mean is for the 20th century, which throws a small wrinkle into the discussion as we were talking of the 30 years from 1950-1980 and the years following.
[DB] Inflammatory snipped.
"One of the scientists, Dr. James E. Hansen of the National Aeronautics and Space Administration's Institute for Space Studies in Manhattan, said he used the 30-year period 1950-1980, when the average global temperature was 59 degrees Fahrenheit, as a base to determine temperature variations."
http://www.nytimes.com/1988/03/29/science/temperature-for-world-rises-sharply-in-the-1980-s.html
"Dr. Hansen informed the lawmakers that the first five months of 1988 were the hottest five-month period on record, averaging four-tenths of a degree above a 30-year (1950-1980) norm of 59 degrees Fahrenheit."
LINK
"The British readings showed that the average global temperature in 1988 was 0.612 degrees Fahrenheit higher than the long-term average for the period 1950 through 1979, which is a base for comparing global temperatures. The average worldwide temperature for that 30-year period is roughly 59 degrees Fahrenheit, the British researchers said."
http://www.nytimes.com/1989/02/04/us/global-warmth-in-88-is-found-to-set-a-record.html
[RH] Shortened link.
From 1991;
"The Goddard group found that the record average surface temperature for the globe was eight-tenths of a degree Fahrenheit above the 1951-1980 average of 59 degrees. The British group found it seventh-tenths of a degree higher than the 1951-80 average."
http://www.nytimes.com/1991/01/10/us/separate-studies-rank-90-as-world-s-warmest-year.html