Another week, another ado over nothing.
Last Saturday, Steve McIntyre wrote an email to NASA GISS pointing out that for some North American stations in the GISTEMP analysis, there was an odd jump in going from 1999 to 2000. On Monday, the people who work on the temperature analysis (not me), looked into it and found that this coincided with the switch between two sources of US temperature data. There had been a faulty assumption that these two sources matched, but that turned out not to be the case. There were in fact a number of small offsets (of both sign) between the same stations in the two different data sets. The obvious fix was to make an adjustment based on a period of overlap so that these offsets disappear.
This was duly done by Tuesday, an email thanking McIntyre was sent and the data analysis (which had been due in any case for the processing of the July numbers) was updated accordingly along with an acknowledgment to McIntyre and update of the methodology.
The net effect of the change was to reduce mean US anomalies by about 0.15 ºC for the years 2000-2006. There were some very minor knock on effects in earlier years due to the GISTEMP adjustments for rural vs. urban trends. In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).
There were however some very minor re-arrangements in the various rankings (see data [As it existed in Sep 2007]). Specifically, where 1998 (1.24 ºC anomaly compared to 1951-1980) had previously just beaten out 1934 (1.23 ºC) for the top US year, it now just misses: 1934 1.25ºC vs. 1998 1.23ºC. None of these differences are statistically significant. Indeed in the 2001 paper describing the GISTEMP methodology (which was prior to this particular error being introduced), it says:
The U.S. annual (January-December) mean temperature is slightly warmer in 1934 than in 1998 in the GISS analysis (Plate 6). This contrasts with the USHCN data, which has 1998 as the warmest year in the century. In both cases the difference between 1934 and 1998 mean temperatures is a few hundredths of a degree. The main reason that 1998 is relatively cooler in the GISS analysis is its larger adjustment for urban warming. In comparing temperatures of years separated by 60 or 70 years the uncertainties in various adjustments (urban warming, station history adjustments, etc.) lead to an uncertainty of at least 0.1°C. Thus it is not possible to declare a record U.S. temperature with confidence until a result is obtained that exceeds the temperature of 1934 by more than 0.1°C.
More importantly for climate purposes, the longer term US averages have not changed rank. 2002-2006 (at 0.66 ºC) is still warmer than 1930-1934 (0.63 ºC – the largest value in the early part of the century) (though both are below 1998-2002 at 0.79 ºC). (The previous version – up to 2005 – can be seen here).
In the global mean, 2005 remains the warmest (as in the NCDC analysis). CRU has 1998 as the warmest year but there are differences in methodology, particularly concerning the Arctic (extrapolated in GISTEMP, not included in CRU) which is a big part of recent global warmth. No recent IPCC statements or conclusions are affected in the slightest.
Sum total of this change? A couple of hundredths of degrees in the US rankings and no change in anything that could be considered climatically important (specifically long term trends).
However, there is clearly a latent and deeply felt wish in some sectors for the whole problem of global warming to be reduced to a statistical quirk or a mistake. This led to some truly death-defying leaping to conclusions when this issue hit the blogosphere. One of the worst examples (but there are others) was the ‘Opinionator’ at the New York Times (oh dear). He managed to confuse the global means with the continental US numbers, he made up a story about McIntyre having ‘always puzzled about some gaps’ (what?) , declared the the error had ‘played havoc’ with the numbers, and quoted another blogger saying that the ‘astounding’ numbers had been ‘silently released’. None of these statements are true. Among other incorrect stories going around are that the mistake was due to a Y2K bug or that this had something to do with photographing weather stations. Again, simply false.
But hey, maybe the Arctic will get the memo.
I want to concur with:
35.”We will need complete transparency in the global temperature records and any ‘adjustments’ made (techniques, methodologies), as clearly climate scientists are not up to the task. Work will need to be verified by the broader scientific community.”
Absolutely true. Anything less is poor science.
And in response to the question about ‘trusting Hansen’. :
24.”I think the point is that we shouldn’t have to trust someone as in a single person or entity such as Nasa GISS to develope what is in effect policy for our country.”
Yes. Isn’t the phrase ‘trust but verify’. Look, we didn’t trust Einstein, we ran independent experiments to confirm his theories. That’s science. The data and the internal adjustment algorithms need to be made completely public and transparent so they all can be verified. This is true even irregardless of the public policy implications that make this more consequential than many other scientific issues.
One of the responses to a comment that used the word ‘hubris’ said: “Sure it’s embarrassing, but only the end result determines whether it matters or not. …”
Wrong attitude! A more appropriate response is to consider this an issue of data collection/analysis integrity and quality and thus, even if the change is small, ensure *processes* need to be put in place to make sure there are not other errors lurking in the adjustment algorithms. So not just this but other datasets should be opened up for independent review.
Whether you are a ‘believer’ or a ‘skeptic’ in AGW, this should be a point of common agreement: Let us at least get the facts right. Let us build confidence in what the facts are through transparency of data and independently reviewable internals of adjustment algorithms.
“More importantly for climate purposes, the longer term US averages have not changed rank. 2002-2006 (at 0.66 ºC) is still warmer than 1930-1934 (0.63 ºC – the largest value in the early part of the century)”
So recent 5 year temps in the US have been a mere 0.03C greater than in the 1930s? Fascinating.
Aha! I was writing up a blog entry on this very topic, and then came here and was happy to see what you wrote; it agrees pretty much with what I said. I also looked at the data a bit, too, to show that despite the claims, this doesn’t change a whole lot.
http://www.badastronomy.com/bablog/2007/08/10/is-it-hot-in-here-or-is-it-just-me/
I’m glad I stopped by before posting!
OK, there is an easy solution to all these complaints.
How about if we double or triple NASA GISS’s budget? Americans complaining about all the stuff that should be done should be in favor of that, and should start writing their Senators and Representatives tomorrow for special earmarks, because they think it’s important to get things right.
Also, express a wish to pay higher taxes for this [hence, non-taxpayers need not apply]. For the surface stations, demand a lot of extra money as well.
I do assume that people complaining about lack of access to everything, have for instance, have explored data.giss.nasa.gov in its entirety, and downloaded the extensive code from http://www.giss.nasa.gov/tools (everyone reads FORTRAN 90, right?), and the code is fairly short, even if there’s 191MB of data to check over as well. [I’ll admit, I only downloaded the code to look at, I didn’t pore over the data sets.] I assume everyone complaining has the expertise to actually help?
Patrick: can you explain to us your expertise in physics, algorithms, statistics, analysis of imperfect data, software engineering, simulations? You have done most of this stuff professionally, right? [Of course, as an anonymous poster, it will be hard for us to check.]
I don’t want to pick on anyone in particular, but a lot of the complaints in this thread have not seemed very well-informed about realistic methods of doing real science… but seem more likely to impede real work. Sigh, science is hard enough to get right as it is.
#52
“If there were no warming trend at all, you’d expect the hottest 10 years to be randomly distributed…”
This is an incorrect assumption. You could see a recent warming, without it being part of an ever increasing function – for example, at the rising phase of a sinusoid.
If you bother to fit some single / multiple frequency sinusoidal models to the data and then examine the residual components, I believe you will quickly negate a requirement for an increasing, sustained signal component i.e. a US warming trend
regards, Steve.
Steve (#48)
“We will need complete transparency in the global temperature records and any ‘adjustments’ made (techniques, methodologies), as clearly climate scientists are not up to the task. Work will need to be verified by the broader scientific community.”
Are you aware of this remarkable device used in the scientific community known as “publishing”? It seems that many of the techniques, methodologies and “adjustments” are found right there, clearly explained in the scientific literature.
As for the global temperature records, did you know that you can get the data for any station in the GISS network here: http://data.giss.nasa.gov/gistemp/station_data/
before or after “adjustments” documented in the “scientific literature” are applied?
I normally advocate complete transparency in science, including open source code and experimental results. But your points in this regard are so silly that they are barely worth replying to.
Steven Mosher (#21) wrote:
Sounds like Quine to me.
Actually he’s not all bad – at least the bits he gets from Pierre Duhem.
No theory follows with cartesian certainty from any given set of observations. Not bad.
So for example, I may have a theory that the world is older than 10,000 years. I might cite geologic formations and the rate at which they form, perhaps fossils, radiocarbon dating, a series of fossilized trees and there rings, the distribution of species, etc.. But interpreting much of this evidence as evidence for the age of the world would involve other theories. Ok.
Then what about the theory that the world is older than five decades? Well, you may not have been here five decades, so I suppose you could hold the theory that any evidence that the world is older than five decades was simply placed there, perhaps by space aliens. Then if someone claims that they are sixty years old and they know that the world has been here at least that long, well, perhaps they only think they are sixty years old, or perhaps they are lying.
Come to think of it, this is where your “social component” might come in handy – but perhaps we will get to that a little later.
Now what about the claim that the world is at least five seconds old. I certainly think it is, but you may regard this as nothing more than a “theory” which is “underdetermined” by the “data,” where the data consists of the experience of “memories” and anything else which I might claim as evidence for an older world. But at this point we aren’t even talking about observation per se – we are talking about memory.
*
So lets move on to observation.
You write:
So does this mean that when I look at an iceberg floating off, it might actually not be floating away? Does this mean that if I am looking at the temperature displayed by a thermometer I am holding is rising, that the temperature might not be rising? Or does this mean that I might only think that the displayed temperature of the thermometer is rising, or that the thermometer is in my hand – or that I have a hand?
If so, I would begin to wonder whether you are engaging in the philosophy of science rather than in some freshman philosophy bullsession. I would also have to wonder just how desperate the “global warming skeptics” have gotten that they find it necessary to appeal to this kind of reasoning.
*
But lets continue.
You write:
This isn’t the way that I normally hear it.
From what I understand, falsification can always be avoided by appealing to another hypothesis. For example, Newton’s gravitational theory predicted that Mercury would have a particular eplliptical orbit, but even in Newton’s day they could see that its orbit tended to shift relative to what Newton’s theory predicted. An auxiliary hypothesis was introduced, namely that there was another planet by the name of Vulcan which was closer to the sun and exerted a gravitational pull on Mercury, causing its orbit to shift.
Now if one claimed that Vulcan was of such a special nature that there would never be any evidence for it other than the observed precession of Mercury’s orbit, then it would be an ad hoc hypothesis. But supporters of this theory made predictions which could be tested independently of that which their hypothesis was introduced to explain. As such, it was an auxiliary hypothesis, not an ad hoc one. As a consequence, it was a scientific theory at the time.
*
But lets focus on the phrase “appealing to other data.” A little later, you speak of a theory as “fitting the data” and “making useful predictions.” Somehow I think these are all interconnected issues. A theory is justified by the evidence, or as you prefer to call it, “the data.” But a theory is also used to explain the evidence, or alternatively, “the phenomena.” And some theories explain more evidence than others. This makes them more useful. Likewise, some theories make more specific predictions than others and this makes them more useful.
But if someone offers a theory involving Descartes’ demon which they then involk to explain any inconvenient fact, they might find this “useful,” but it wouldn’t be useful in quite the same way. Why? Because it would be consistent with anything. As such, it wouldn’t make any specific predictions. Or to put it another way, it wouldn’t be testable.
However, if someone offers a theory which explains the orbit of the planets and the paths of objects which fall on the earth, one which can be used to make specific calculations of where things will be at any specific moment, this is useful. And if it does so and works under a great many circumstances, explaining a wide variety of phenomena, then it is even more useful. At this point we have good reason for not abandoning it the first time we encounter evidence which tends to disconfirm it. It is reasonable to look for an auxiliary hypothesis.
Why?
Because there exists a large body of evidence which supports that theory. Or alternatively, because that theory explains a great deal of evidence. Much of this evidence is independent of other evidence. Someone investigates the paths of planets in the outer solar system. Someone else investigates the paths of the moons around Jupiter. Someone else studies the inner planets or the orbit of the moon.
Then there are those who drop cannon balls or apples. All of these largely independent lines of investigation examine phenomena which is explained by Newton’s gravitational theory, but they also provide evidence for the theory. And even when some later theory comes along and supercedes an earlier theory, it must be consistent with and account for the evidence which the earlier theory accounted for.
This is in fact the basis for what is known as the correspondence principle between classical mechanics and quantum mechanics, between classical mechanics and special relativity, and between Newton’s gravitational theory and Einstein’s General Theory of Relativity. In a certain sense, while much of the form of an earlier theory is discarded, the material of that theory – consisting of the evidence which justified it and which it accounted for – is preserved in the theory which supercedes it.
*
A hypothesis or theory which is justified by multiple lines of investigation is generally justified to a far greater degree than it would be if it were simply justified by any one line of investigation considered in isolation.
Now the vast majority of the scientific community has accepted the view that:
1. The earth is getting warmer;
2. greenhouse gases are largely responsible for this; and,
3. That what has been raising the level of greenhouse gases are human activities.
You on the other hand are still stuck on (1). Not dogmatically denying it, I understand, but simply doubting it with your healthy, “scientific” skepticism.
So in the interest of science, lets look at the evidence:
1. We have surface measurements in the United States which show an accelerating trend towards higher temperatures.
2. These are temperature measurements being taken by planes and satellites, and they show that the troposphere is warming – just as we would expect.
3. The stratosphere is cooling – just as is predicted by the anthropogenic global warming theory. (Incidently, the latter of these is something which cannot be explained by any theory based upon solar variability.)
4. Measurements of temperatures at the surface of the ocean show that these temperatures are increasing.
5. Measurements of temperatures at various depths show warming as far down as 1500 meters.
6. Measurements of sea level show that it has been rising just as we would expect from thermal expansion.
7. Gravitometric measurements of Greenland and Antarctica which are showing net ice loss in both cases.
8. We can witness sea-ice loss in the Arctic which is dramatically accelerating.
9. We are seeing the acceleration of glaciers in both Greenland and Antarctica, particularly within the last few years. Greenland is no doubt affected by black carbon, but Antarctica is much more isolated.
10. We are witnessing the rise of the tropopause.
11. There is the poleward migration of species – just as one would expect with rising temperatures.
12. There is the increased intensity of hurricanes just as we would expect from rising sea surface temperatures.
13. There is the accelerating decline of glaciers throughout the world with few rare exceptions.
14. There is the rise in temperatures at greater depths in the permafrost.
15. There is the rapid expansion in the last few years of thermokarst lakes throughout parts of Siberia, Canada and Alaska.
16. There are changes in ocean circulation – just as has been predicted by climate models, for example, with temperatures rising more quickly overland.
17. We are seeing the disintegration of permafrost coastlines in the arctic.
18. We are witnessing changes in the altitude of the stratosphere.
19. We are getting temperature measurements from countries throughout the world which show the same trends.
20. When we perform measurements using only rural stations, we see almost identical trends compared to those which we get when we perform measurements with all surface stations.
All of this constitutes evidence for global warming. Some of it constitutes strong evidence for a particular theory of the mechanism by which this warming is taking place. But you would have us discard a conclusion which is based upon such a large body of evidence based upon a fraction of a degree for a particular year for a relatively small region of the globe.
Somehow I doubt a fidelity to science is what motivates you.
I had written (#19):
papertiger (#29) responded:
Different country – Hadley out of England – notice the UK in the website address. But I suppose they could be part of a global conspiracy. You have to watch those conspiratorial types pretty darn closely – particularly the scientists when they start getting uppety….
As for the Arctic sea, I don’t know its political affiliation for certain, but the blue would seem to be a dead giveaway.
Gavin, if the US48 corrections indeed were imperceptible in the global record, I would expect the GISS global record to either not change at all or to roughly correspond to the US48 corrections (mainly due to rounding errors since the effect is small).
However diff-ing the GISS global record versions, I find none of the above. E.g. the 2005 US48 correction of -0.3°C is reflected as a +0.01°C in the new global dataset. How come?
[Response: What’s your source for that? The wayback machine version from May 17 2007 is 0.01 degree greater than the current version. i.e. it went down with the correction as you would expect. The data for Fig.A2 doesn’t appear to have been updated yet (and the update stamp confirms that). I’ll ask that they do. – gavin]
Steve…
“If you bother to fit some single / multiple frequency sinusoidal models…”
Some basics…
Fitting any old set of functions to a given data set is often not very useful. Usually one has some justification for the basis functions one is using what’s yours ? You do realize that given enough terms it is possible to fit any function (data set) exactly…of course such fits are not useful in the context of this issue.
Have you tried using only say 75% of the data set and doing the same fits and then using the other 25% to see if your fits have any predictive power at all ?
btw; How does this affect the accuracy of Hansens’ models? The ones that were portrayed as so stunningly accurate?
[Response: Not at all. If you recall, the evaluation of those 1988 projections was against the global data, which hasn’t changed. – gavin]
And what did the 1930s bring the United States? Drought and the dustbowl throughout the midwest. Perhaps Steinbeck’s greatest novel, “The Grapes of Wrath”. Images by folks like Dorthea Lange and Walker Evans that burned into the soul of the country.
“only” 0.03 warmer than a time that brought significant hardship to many, many farmers.
And, hey, keep in mind that we’re really concerned about GLOBAL warming. The current temps are part of a global phenomena, the high US temps in the 1930s weren’t.
[[If you want me to believe in catastrophic global warming, you’ve got to convince me it’s not just a case of Garbage In Garbage Out. So far, I’m not convinced. I’m less convinced today than I was last week.]]
Then you’re not paying attention.
Global warming doesn’t rely only on the surface temperature station record, though that record is reliable enough. It has been detected in sea surface temperatures (are there urban heat islands and poorly sited temperature stations on the ocean?). It has been detected in boreholes. It has been detected in the record from balloon radiosondes. It has been detected in the record from satellites. It has been detected in melting glaciers, tree lines moving toward the poles, animals migrating toward the poles. It has been confirmed again and again and again and those who doubt simply don’t understand the situation.
True enough, any curve shape — even a step or a spike — can be reproduced with sinusoids. But what physical process does each sinusoid represent?
[[I am wondering if the ocean is rising and flooding out Indonesia, why isn’t it flooding Cape Cod? are they not all at sea level?]]
Sea level is not the same everywhere in the world. It is affected by the Earth’s rotation, gravitational anomalies, currents, differences in local salinity, and differences in local temperatures. Sea level on average is rising. That doesn’t mean it’s rising at exactly the same rate everywhere in the world.
“but, given the fact that the US has the most reliable and well-maintained network, it raises concerns about the quality of data we have been using across the board.”
On what do you base the idea that our network is best? Why is it better than for example that of Sweden?
Gavin:
The two charts you present are grossly misleading, is there no way to amend them and use the same y-axis.
43: “Unfortunately, as ClimateAudit has documented, a number of climate researchers have maintained their data, methodologies, algorithms and source code are private.”
“[Response: What is secret? The algorithms, issues and choices are outlined in excruciating detail in the relevant papers: http://data.giss.nasa.gov/gistemp/references.html – gavin]”
How is “outlining” anything equivalent to actually posting the data and code?
[Response: Because a) the raw data are publicly available and b) papers are supposed to contain enough detail to allow others to repeat the analysis. If a paper says ‘we then add A and B’, you don’t need code that has “C=A+B”. – gavin]
I’m a physician and not a climate scientist, and am a little confused about the points being made here. Are people arguing that the GISS correction suggests that N America is not warming, that the hemispheric or global means are not increasing or what? How do the respondents tie this in with sea temperatures and satelite data. What do they think of the recent correction of the satelite data anomaly? And what then of the measured sea level rises? Sorry it’s just I’m having trouble following the logical thread of this argument and some of the conclusions being bandied around.
An important statement relevant to this issue was made as part of the recommendations from the CCSP Synthesis and Assessment Report on Tropospheric temperature trends:
http://www.climatescience.gov/Library/sap/sap1-1/finalreport/default.htm
see particularly ch 6 (recommendations)
http://www.climatescience.gov/Library/sap/sap1-1/finalreport/sap1-1-final-chap6.pdf
“To ascertain unambiguously the causes of differences in data sets generally requires extensive metadata for each data set. Appropriate metadata, whether obtained from the peer-reviewed literature or from data made available on-line, should include, for data on all relevant spatial and temporal scales:
• Documentation of the raw data and the data sources used in the data set construction to enable quantification of the extent to which the raw data overlap with other similar data sets;
• Details of instrumentation used, the observing practices and environments and their changes over time to help assessments of, or adjustments for, the changing accuracy of the data;
• Supporting information such as any adjustments made to the data and the numbers and locations of the data through time;
• An audit trail of decisions about the adjustments made, including supporting evidence that identifies non-climatic influences on the data and justifies any consequent adjust- ments to the data that have been made; and
• Uncertainty estimates and their derivation.
This information should be made openly available to the research community.”
“The independent development of data sets and analyses by several independent scientists or teams will serve to quantify structural uncertainty and to provide objective corroboration of the results. In order to encourage further independent scrutiny, data sets and their full metadata should be made openly available. Comprehensive analyses should be carried out to ascertain the causes of remaining differences between data sets and to refine uncertainty estimates.”
Last week, Bush signed a bill on “America COMPETES”. There is a relevant part on the open exchange of data and metadata:
“SEC. 1009. RELEASE OF SCIENTIFIC RESEARCH RESULTS.
(a) Principles- Not later than 90 days after the date of the enactment of this Act, the Director of the Office of Science and Technology Policy, in consultation with the Director of the Office of Management and Budget and the heads of all Federal civilian agencies that conduct scientific research, shall develop and issue an overarching set of principles to ensure the communication and open exchange of data and results to other agencies, policymakers, and the public of research conducted by a scientist employed by a Federal civilian agency and to prevent the intentional or unintentional suppression or distortion of such research findings. The principles shall encourage the open exchange of data and results of research undertaken by a scientist employed by such an agency and shall be consistent with existing Federal laws, including chapter 18 of title 35, United States Code (commonly known as the `Bayh-Dole Act’). The principles shall also take into consideration the policies of peer-reviewed scientific journals in which Federal scientists may currently publish results.”
As a climate researcher, I wholeheartedly support the above principles. In my opinion research scientists (and particularly government research scientists) should not be given any “choice” in this matter if they wish to receive government research funding, publish their research in the peer reviewed journals of the major professional societies, and have their data used in assessment reports.
Yes all this adds to the cost of doing research, and even the COMPETE bill is apparently an unfunded mandate. But it’s a cost we need to accommodate in some way. I have seen too many examples in the climate field where scientists do not want to make their data and metadata available to skeptics such as Steve McIntyre since they don’t want to see their research attacked (and this has even been condoned by a funding agency). Well, in the world of science, if you want your hypotheses and theories to be accepted, they must be able to survive attacks by skeptics. Because of its policy importance, climate research at times seems like “blood sport.” But in the long run, the credibility of climate research will suffer if climate researchers don’t “take the high ground” in engaging skeptics.
With regards to Steve McIntyre and climateaudit. In the early days of McIntyre’s attacks on the “hockey stick”, it was relatively easy to dismiss him as an industry “stooge.” Well, given his lengthy track record in actually doing work to audit climate data, it is absolutely inappropriate in my opinion to dismiss him. Climateaudit has attracted a dedicated community of climateauditors, a few of whom are knowledgeable about statistics and are interesting thinkers (the site also attracts “denialists”). For all the auditing activity at climateaudit, they have found relatively little in the way of bonafide issues that actually change something, but this is not to say that they have found nothing. So taking the high ground, lets thank Steve and climateauditors if they actually find something useful, assess it and assimilate it, and move on. Such actions by climate researchers would provide less fodder for the denialists, in my opinion.
it is still curious the difference between the US and world readings.In Britain the 1930’s temperatures were only matched very recently. Indeed when I was a boy in the 1960’s older people were always saying how much warmer it was then. It turns out they were right. Why is this and which parts of the world have warmed to give the sharp upward increase in global temperatures?.
[Response: The GISTEMP website allows you to compare any two time slices, so have a look there, comparing say 1930-1935 to 2000-2005. You’ll find that almost everywhere is warmer than then (including Europe), but not the SE US, nor much of the Eastern Pacific. – gavin]
I may have missed it, but I don’t think anyone has linked James Hansen’s response to this issue.
http://www.columbia.edu/~jeh1/distro_LightUpstairs_70810.pdf
By the way, I tried to contact him to be added to his email list and found that his email has been disabled. Given the vicious attacks on him by right wing blogs and talk radio, I suppose his inbox has been overwhelmed by messages calling for his head. It is sad. He is an outstanding scientist of highest integrity and one of my heros – a man who will speak the truth to power at whatever cost.
[ Barton: Sea level is not the same everywhere in the world. It is affected by the Earth’s rotation, gravitational anomalies, currents, differences in local salinity, and differences in local temperatures. Sea level on average is rising. That doesn’t mean it’s rising at exactly the same rate everywhere in the world. ]
Odd you didn’t mention that maybe some plates might be sliding lower into the ocean. Exactly how much of a rise is there? And how does it vary across the globe?
Gavin said:
You might want to rethink that, considering the denial folks seem to need to be led around by the nose.
Theory laden observation. one of my favorite examples.
from Hansen 2001:
“The strong cooling that exists in the unlit station data in the northern California region is not found in either the periurban or urban stations either with or without any of the adjustments. ”
Rural can’t be cooler. And it can’t be cooler after our perfect adjustment scheme.
Go figure. we are talking about the early 1900s here. and defining urban/small town/rural using 1980 population data and a photo from a satellite.
They continue:
“Ocean temperature data for the same period, illustrated below, has strong warming along the entire West Coast of the United States. This suggests the possibility of a flaw in the unlit station data for that small region.After examination of all of the stations in this region, five of the USHCN station records were altered in the GISS analysis because of inhomogeneities with neighboring stations (data prior to 1927 for Lake Spaulding, data prior to 1929 for Orleans, data prior to 1911 for Electra Ph, data prior of 1906 for Willows 6W, and all data for Crater Lake NPS HQ were omitted so these apparent data flaws would not be transmitted to adjusted periurban and urban stations.”
The ocean is warm, so the cool station record must be wrong. the 5 stations that don’t agree; they must be wrong. And we know they must be wrong because we have records of the temperature of water, taken by guys hauling in buckets of water somewhere in the pacific.
Now, very often on the coast the land tracks the ocean temp. Let’s see where these stations are.
In this region ( they don’t specify the exact extent of the region) they mention:
1. Lake spaulding. You go google map that. It’s about 200 miles from the warm ocean, on the other side of the mountains.
2. Willows a bit closer to the ocean. It’s in the sacramento Valley.
3. Electra. About 200 miles from the ocean on the far side of a mountain.
4. Crater lake: closer to the ocean, but in a crater,
separated from the ocean by a ridge line.
5. Orleans. Much closer to the ocean. Behind a big ridge line.
I’m stumped. Why would these 5 sites show unusual cooling ? Hansen’s reply: they can’t. There must be something wrong with the station data.
Must. well, There are multiple explanations:
1. could be something wrong with the Ocean measurements.
2. Could be something amiss with the assumption that these site records always correlate well with the ocean data.
3. Could be something wrong with the warmer stations they are compared to. where is the list of the other stations.
How to decide? confirmation bias to the rescue.
Dump the cold data.
Continuing:
“If these adjustments were not made, the 100-year temperature change in the United States would be reduced by 0.01°C.”
A Small amount. does not even matter. Why drop it?
re: “Another week, another ado over nothing.”
If that is the last warming error in the GISS temp analysis then perhaps it is an embarrassing, but minor issue.
After an error is found an organization’s sales staff typically weigh in with “It is only one small error, the rest of the product is still solid”. Meanwhile the technical folks scurry around and make sure that that was the only mistake. Take a step back and look Gavin, your business card may need some updating.
re: “What is secret? The algorithms, issues and choices are outlined in excruciating detail in the relevant papers: http://data.giss.nasa.gov/gistemp/references.html”
Sorry, I don’t see the excruciating detail. I found no pseudo code, no code, no scripts. Had Hansen released code and scripts Steve McIntyre would have caught the problem long ago. That just made him work harder. Until code and scripts are fully released, other errors are going to be slower to surface. I am betting you know this.
One mistake and the “gotcha” squad comes out in full force and says the whole enterprise is wrong! Baloney!
The modelers admitted the error and promptly corrected it. This is what should be focussed on.
Jeremy Bernstein, the physicist and science writer visited Erwin Schrodinger,near the end of his life.Schrodinger developed the wave mechanic equations of quantum mechanics.Schrodinger told Bernstein “There is something that the ancient Greek scientists knew that we seem to have forgotton.” He paused and then said “and that is modesty.”
It seems that Schrodinger was wrong. The modelers had the humility to openly acknowledge the error and to correct it.
It’s already been this hot (1998) in the past. In other countries it has been hotter in other years. Icebears still live. There have always been droughts and floods. Now we just get informed better than 50 years ago and before.
In my opinion the rate of change doesn’t say anything about the following years. Temperature records show that after one year with an increase (maybe even a dramatic increase) – one or two years later it has been cooling again.
From what I gather there is no gain of momentum but a lot of jitter on the raw data, as well as the annual means.
If anyone could point me to (freely accessible?) scientific literature suggesting something like a momentum in global annual mean temperatures, please feel free to post: I am hungry to learn every day!
PS: I am currently working on some statistics concerning temperatures (min, avg, max). I will let you know when I’m ready to “publish”… As a preview you can look at this:
http://www.07000deuschl.de/co2/pubs/avgcharts_ffm/avgs.jpg
http://www.07000deuschl.de/co2/pubs/avgcharts_ffm/deriv.jpg
http://www.07000deuschl.de/co2/pubs/avgcharts_ffm/index.html
What do you mean its “estimated” to be? You don’t know what the error is? What’s the error on the error of the GST?
Stop obfuscating. It may not be better than Sweden–but I imagine it is. That’s not the point. What’s the network like in Botswana? Nigeria? Rural Mongolia? Siberia? Geez.
It is inappropriate and unprofessional to dismiss anyone and an “industry stooge” simply because they disagree with you. Unsubstantiated ad hominem attacks are never appropriate.
[Response: If we knew exactly what the error was, we’d fix it and then it would be zero. All errors are therefore estimated (based on spatial coverage, measurement accuracy, etc.). – gavin]
So, it is climatically significant that 1930-1934 is 3 hundredths of a degree cooler than 2002-2006, but it is not climatically significant that 1934 and 1998 have now changed places, by 3 hundredths of a degree.
Can you explain your criteria for assessing when 3 hundredths of a degree is climatically significant and when it is not? Because from where I sit it looks like the criteria is “significant if it supports the AGW hypothesis, insignificant if not”.
[Response: The longer the average the more relevant, and the more significant the difference. I was just trying to make the point that long term averages didn’t shift. If we consider 0.1 (as above) the ‘significant’ level for single years, the five year mean significance is roughly 0.1/sqrt(5)= 0.045 and so the 1930-1934 and 2002-2006 difference isn’t significant, but the difference to 1998-2002 certainly is. – gavin]
2001-2006 is longer than 1930-1934 – what does it mean to compare averages of periods of different length?
And may we please get preview back?
[Response: I mistyped. It is 2002-2006, I’ll correct the post. Thanks. (Preview is coming but for some reason the compreval plugin doesn’t want to work). – gavin]
While the error may be minor it does make good copy.
Can someone tell me – what are the primary sources of scatter in the global mean temp from year to year?
[Response: El Nino/La Nina is important, the North Atlantic Oscillation during the winter can be seen, but mostly it is just ‘weather’ – unforced variability (which locally can be quite large) averaging out to give deviations of about 0.1 deg C from year to year. – gavin]
Just for global warming skeptics:
http://www.nowpublic.com/english_man_swims_1km_north_pole_raise_climate_change_awareness
Just for everyone else on the cause of global warming (non-scientific):
It’s true that it’s happening. It’s true that it is new to the Earth, CO2 levels are higher than they’ve been for … how many years? The question is the cause: It’s not from living plants, they reduce CO2; It’s being caused by a change of some kind… It sounds reasonable to assume that the change must be large to have so large an effect on the amount of CO2. It’s most likely a living organisim that emits CO2 whose population is consistently increasing indicating that has no natural predator to thin out their numbers… Could it be a fish? nah, we’d kill them and eat them. Could it be an animal? Could be, but we’d keep their numbers down through hunting/we’d see them. Could it be an insect, nah we’d kill them to keep their numbers down, they are pests after all. Well, what’s causing it: “I have met the enemy and them are us”.
Re #56: [All of this constitutes evidence for global warming. Some of it constitutes strong evidence for a particular theory of the mechanism…]
An interesting & informative read, if a bit long, but I think it’s still backwards. After all, most if not all of the points you cite as evidence of warming would be equally valid for warming from any cause, whether it be an increase in the sun’s output, cosmic rays, or the side-effects of UFO exhaust. That means having to refute each and every alternative explanation that the denialist community dreams up – and denialists being what they are, having to repeat each separate refutation ad nauseum.
Why not approach it from the other direction, from the theory of the mechanism? The amount of CO2 in the atmosphere has increased, a fact that only the completely irrational denialists try to dispute. That this increase is from fossil fuel burning is also beyond any reasonable question. The properties of CO2 have been measured quite accurately, and are likewise difficult for the denialists to dispute. So from that, and known radiation theory (which has been experimentally verified in many ways), we discover that there is this mechanism by which increasing atmospheric CO2 causes warming.
If the denialist community wants to try to refute this mechanism, they have to do some hard math and/or experimental science, rather than just randomly sniping at this or that data set. Instead of the foundation for the theory, your long list of warming examples becomes evidence supporting it. If one or more are shown to fail, due to instrument error or the effects of other climate drivers (e.g. sulfate aerosols), that doesn’t undermine the existence of the mechanism.
Gavin:
Steve McIntyre graciously accepted my suggestion and the two figures you present now are viewable side-by-side. Hopefully it will stimulate further explorations and careful assessments of the published temperature records.
RE 77.
Matthias, your data is from one city in Germany. Hardly data representative of the globe.
J
What I’d like to see is a least-squares analysis of these data sets, which would calculate a growth rate over the period of the data sets. Simple maxima and minima do not make a trend by themselves. The 1934 data for the US might be just an aberration in the trend. As I look at the graph of the data, just eyeballing it as it is, it certainly appears to me that there is a clear upward trend over the course of the 20th Century in the US data set.
Some of the comments also make it clear to me that there are a lot of folks who think of “pollution” as generic. That is, of course, total nonsense. The effects of particulates (e.g. fly ash), and carbon dioxide are quite different, as I’m sure those of you who are actually scientists know.
[Response: US trend (1880-2006): 0.043 +/- 0.021 deg C/decade (95% confidence levels), significant but less than the global trend. For the more recent period 1975-2006: 0.3 +/- 0.16 deg C/dec. – gavin]
It’s really no surprise how the antiwarming crowd jumps on any small error in the science (in this case a minor error in one data set) to discredit all the science. It is the same tactic the anti-evolutionists use. They do not understand that both theories, AGW and evolution, are based on multiple converging lines of evidence and to bring down either theory would require seriously attacking each of those independent lines of evidence successfully. This instance wasn’t even a small dent and still the fools cry hoax.
James (#84) wrote:
My apologies for the length, particularly so soon in the thread. Believe it or not, I was actually inclined to write something a bit longer to address some of your later concerns and to more properly treat some technical issues, but that would have been imposing a great deal upon everyone else, and I believe that given the length I had imposed more than enough as it is. Besides, what you don’t mention at one point you can always bring in later.
Granted, for something general purpose, one should focus more on the mechanism, particularly anthropogenic greenhouse gas emissions. We actually have that nailed. Likewise, there should be more focus on the foundations of climatology in physics. However, I was responding to Steve Mosher – and he is inclined towards skepticism with regard to the mere fact of global warming. Likewise, McIntyre is trying to cast doubt on the phenomena by focusing on a small fraction of a percent in temperature for one year in the United States – which is afterall what this thread is about. So focusing more on the warming and less on the mechanism seemed warranted, given the context.
“Stop obfuscating. It may not be better than Sweden–but I imagine it is. That’s not the point. What’s the network like in Botswana? Nigeria? Rural Mongolia? Siberia? Geez.”
How am I obfuscating here? Your original post was along the lines that since “the best” network hads given rise to an eror all the other were in doubt. I took Sweden as an example since I happen to be staying there for a few months now.
The reliability of data from different regions is of course important to know when deciding how reliable the averages are, but just assuming that our data is the best is no good. Your mention some countries you find unreliable, but what about Australia, New Zeeland, Japan, South Africa? Or Canada, which has more land area than the US and thereby a larger part of the world average.
#82 (including response)
Doesn’t the scatter in the surface temperature record really boil down to
the fact that most of the energy in the climate system is stored BELOW the
surface in the oceans? Thus, vertical transports of energy that would be
insignificant when compared to the total sub-surface energy can have a
measureable impact on SURFACE ocean temperatures.
88. “It’s really no surprise how the antiwarming crowd jumps on any small error in the science …to discredit all the science.”
This was a classic tactic of the tobacco industry. Any small error in a science article was used to describe the research as ‘flawed’ and unusable. Tobacco lawyers also sued researchers to get patient data: I know one scientist who was unable to visit Texas for a number of years because there was a warrant out for his arrest; he had refused an order obtained by the tobacco industry to turn over his patient records and data.
re 92
Don’t any of those foldk read their Grandmother’s journals for when the apples bloomed?
This year the apples bloomed earlier than in 1934.
It is hard to argue with an apple tree.
#6: Lee
All scientists are skeptics. To “believe” is associated with faith and religion, not science. To “deny” is associated with “believing” regardless of contrary evidence, and regardless of the fact that doing so is unscientific.
Those who use this terminology easily expose themselves as naive, manipulated, and propagandized. This goes both ways.
Roman,
No. I was explicitly looking at the total change in temp over a stated time interval, with the beginning and end times stated. ie, the total change over the last century, between an implicit zero at the beginning, to the end, was somewhere between 0.8C and 1.1C. That change is not sensitive to the base reference. Changing the base would change the absolute values for beginning and end, but would leave the difference between them unchanged.
Yes, it is slightly awkward – but only slightly. I chose to state it that way because claims are being bandied all over the internet that the change in the temp/trend was several percent change.
Here is the response of an Inuit child about all this climate change:
http://www.putfile.com/pic.php?img=6219791
Steve Mosher (#74) wrote:
Hansen (2001):
A closer look at United States and global surface temperature change
J. Hansen, et al (2001)
http://pubs.giss.nasa.gov/docs/2001/2001_Hansen_etal.pdf
They state:
As such, they are responding to sources of contamination which may not have been regarded as that important – prior to 1929. Not only does this have little to do with current trends, but it demonstrates a concern for accuracy. And as a matter of fact, the elimination of such contamination tends to reduce the apparent rise in temperatures over the twentieth century rather than magnify it.
In an earlier thread you claimed to be interested in accuracy and were attacking urban sites for their presumed contamination by the urban heat island effect. We of course pointed that you get virtually the same warming trend whether you use all stations or just rural stations – which you didn’t even seem to acknowledge.
Now Hansen is correcting some fairly obvious contamination, and you find this particularly problematic because he is applying some common sense. You vaguely suggest it involves ulterior motives so on the basis of a kind philosophic skepticism which on close analysis would appear to be of the radical kind roughly on par with Descartes and Hume.
For some reason, I don’t think that identifying the actual trends and causes of world temperatures (or more generally, for that matter) is your highest priority.
96 Lee
Then you are not talking about anomalies. An anomoly is a departure from a norm. If you want to say taht you are looking at the change from some staring point and some end point, you are entitled to do so, but don’t call that an anomoly unless you want us to believe that somehow the temperature at the beginning of the 1900s was the norrmal state of affairs.
If this webiste wishes to edit my post, I would appreciate it if they would not make it look like I was quoting myself. Thanks.
Roman, a change in anomaly over that time period is equivalent to the change in temp over that period. If the anomaly went from -0.3C to +0.7, then the change in anomaly, is equal to the change in temp, is equal to a delta of 1.0C.
Make any change to the reference period, change the baseline, and all that happens is you create equivalent offsets to the beginning and ending anomaly values, and the delta is unchanged.
My percentage calculation references the delta temp (or delta anomaly, which is equivalent), not the absolute anomaly value.
I wasn’t even imprecise in my language. The adjustment causes a slight change in the anomaly values post 2000, which changed the delta temp, which is what I explicitly referenced in my percent calculation.