Reposted from Jennifer Marohasy’s website.
THERE are four official global temperature data sets and there has been much debate and discussion as to which best represents change in global temperature.
Tom Quirk has analysed variations within and between these data sets and concludes there is 1. Substantial general agreement between the data sets, 2. Substantial short-term variation in global temperature in all data sets and 3. No data set shows a significant measurable rise in global temperature over the twelve year period since 1997.
Global Temperature Revisited
Article by Tom Quirk
One of the most vexing things about climate change is the endless debate about temperatures. Did they rise, did they fall or were they pushed? At times it seems like a Monty Python sketch of either the Dead Parrot or the 5 or 10 Minute Argument.
However it is possible to see some of the issues by looking at the four temperature series that are advanced from:
GISS – Goddard Institute for Space Studies and home of James Hansen,
Hadley Centre – British Meteorological Office research centre
UAH – The University of Alabama, Huntsville, home of Roy Spencer with his colleagues including John Christy of NASA and
RSS – Remote Sensing Systems in Santa Rosa, California, a company supported by NASA for the analysis of satellite data.
The first two groups use ground based data where possible with a degree of commonality. However since 70% of the surface of the earth is ocean and it is not monitored in a detailed manner, various procedures with possibly heroic assumptions and computer modelling, are followed to fill the ocean gap.
The last two groups use satellite data to probe the atmosphere and with the exception of the Polar Regions which are less than 10% of the globe, they get comprehensive coverage.
One question is of course are the two groups measuring the same temperature? After all the satellite looks down through the atmosphere, while the ground stations are exactly that.
There is an important distinction to be made between measuring the temperature and measuring the change in the temperature. Since the interest is in changing temperatures then what is called the global temperature anomaly is the starting point. The issue of measuring absolute temperatures should be put to one side.
Data from 1997 to 2009 was drawn from the four group websites on the 28 April 2009. When data for 1997 to early 2008 was compared to data acquired in early 2008 differences were found as shown in the first table.
This is evidence of substantial reprocessing and re-evaluation of data. This is not unusual with complicated analysis systems but there is so much interest in the results that adjustments are regarded with great suspicion. This is the fault of those publishing the temperature data as they fail to make the point that monthly and even yearly measurements are about weather and not climate.
The latest series of temperature anomalies are shown in the graph where the monthly data has been averaged into quarters. All statistical analysis that follows is on the monthly data unless stated otherwise.
From inspection, there is substantial agreement over the years 1997 to 2008. This can be statistically measured through correlations. This is a measure of how closely related the series may be. A value of 0 implies independent series while a value of 1 implies complete agreement. The correlation in turn indicates the degree of commonality in the comparison.
This is remarkable agreement given the two very different techniques used.
It is important to note that the two satellite analysis groups draw measurements from the same satellites. So the differences in temperatures are a result of analysis procedures that are not simple. In fact corrections to the data have been the subject of exchanges between the two groups.
The ground based measurements also have a common data base but it is clear and acknowledged that the two groups have different analysis procedures. While the satellite analysis procedures have converged to reduce their differences over the last thirty years, this has not been the case for the ground based procedures.
It is also clear looking at the measurements that there are substantial short-term, say less than 2 years, variations over the period 1997 to 2009. In fact, while the overall monthly variations show a scatter with standard deviation of 0.20C, the month to month variations are 0.10C. This is a measure of features that are clear in the data. The short run sequences of temperature movement are a reflection of variability in the atmosphere from events such as El Ninos (1997-98) and La Ninas.
Looking for a simple trend by fitting curves through a highly variable series is both a problem and a courageous exercise. The results on an annual rather than a monthly basis are given in the third table. The problem of dealing with real short term variations was resolved by ignoring them. 
So for twelve years there has been a rise 0.10C with a 140% error, in other words, no significant measureable temperature rise. You can play with the data. If you omit 1998 then you can double the change. But 1998 was an El Nino year followed in 1999 by a La Nina. If we omit both years then the results are unchanged.
However the lesson from this is to look at the detail.
There is so much variability within the 12 year period that seeking a trend that might raise the temperature by 20C over 100 years would not be detectable. On the other hand there are clearly fluctuations on a monthly and yearly scale that will have nothing to do with the predicted effects of anthropogenic CO2.
The twelve year temperature changes from the data of the four analysis centres reveal some possible differences. Since there is a high degree of commonality amongst the results, any differences may be systematic. Both the GISS and Hadley series show a larger temperature increase then the satellite measurements. This may be due to urban heat island effects.
Finally, if you are looking for temperature increases from CO2 in the atmosphere, then you should choose the satellite approach of measuring temperatures in the atmosphere!
Short term, less than thirty years, temperature series are not the place to seek evidence of human induced global warming.
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Tom Quirk lives in Melbourne, Australia.
To read more from Dr Quirk click here http://jennifermarohasy.com/blog/author/tom-quirk/
The photograph is from Anthony Watt’s website that details his program of photographically surveying every one of the 1221 USHCN weather stations in the USA which are used as a “high quality network” to determine near surface temperature trends in the USA, read more here http://wattsupwiththat.com/test/
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“”” Miles (23:20:27) :
This whole thing confuses the heck out of me. I think there needs to be an international grid standard of definable points ( every 5 minutes around the globe ) that are measured upon at definable intervals ( hourly ) and in 3 dimensions and get the stinking data. The temperature at any defineable point in the grid should independently verified and then there can be no debate on the temapeature differentials between points in time. “””
Have you calculated how many measuring stations that is ? And what do you do over the oceans does your grid stay localised with the solid planet or with the meandering water on top.
At some point you have to decide whether to measure surface temperatures or air temperatures (is that lower troposphere?).
It seems to me that Anthony’s errant owl boxes, are measuring air temperatures, and all the ancient history record data over the ocean were measuring water temperatures; and that was water from some arbitrary depth; wherever a bucket thrown overboard stopped sinking; then it became water from some arbotrary depth wherever some ship happened to have it’s cooling water intake; and of course depending on how loaded the ship was at the time.
Of course in Jan 2001 it was reported that ocean buoy measurements made at a fixed depth of one metre in the water, and a fixed height of three metres in the air showed that the water temperatures and the air temperatures are not correlated; which means that the air temperatures are not recoverable form hisorical water temperatures. Since that buoy data started around 1980; we can deduce that any historic ocean temperature data prior to 1980 is total garbage.
So that means we actually have measured global temperature data, only since3 about 1980, about the same time frame that we have for the polar orbit satellite data, that gives us Ice records.
It seems to me that the earth’s surface is the primary source of the emitted long wave IR radiation; not the atmosphere; so it would seem that surface temperatures are what should be measured; not air temperatures.
So that makes all the oceanic water data, and all the land based air data; to be somewhat meaningless.
I suppose the satellites can read sea surface temperatures; but the whole sampling process seems hoky to me.
And of course it is not very meaningful after you get it; about as meaningful as averaging the phone numbers in yourt local phone directory.
Well what does it matter so long as the taxpayers keep paying you to measure whatever it is you measure.
The standard deviation tells all.
Latest Ocean Heat Content Numbers from National Oceanographic Data Centre, and published in GRL are here.
Levelling off? Maybe. Cooling? nope. Besides, it would take a long, steep and sustained cooling trend to lose all that heat gained since 1955…
NewScientist mentions another difference between Hadley and GISS:
According to the dataset of the UK Met Office Hadley Centre,…1998 was the warmest year by far since records began, but since 2003 there has been slight cooling.
But according to the dataset of NASA’s Goddard Institute for Space Studies…2005 was the warmest since records began, with 1998 and 2007 tied in second place.
Why the difference? The main reason is that there are no permanent weather stations in the Arctic Ocean, the place on earth that has been warming fastest. The Hadley record simply excludes this area, whereas the NASA version assumes its surface temperature is the same as that of the nearest land-based station.
Phillip Johns (13:00:00):
It would take very little time to show that the Levitus et al. “corrections” of XBT measurements and their exclusion of inconvenient Argus data is what produces “all that heat gained since 1955.”
Philip Johns
Thanks. Interesting link.
ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf
My first thought is how they can have such accurate measurements back to 1955 and are we comparing the same data up to the present date.
This from first para of the pdf;
“We provide estimates of the warming of the world ocean
for 1955–2008 based on historical data not previously
available, additional modern data, correcting for instrumental
biases of bathythermograph data, and correcting or excluding
some Argo float data. The strong interdecadal variability of
global ocean heat content reported previously by us is reduced
in magnitude but the linear trend in ocean heat content remain
similar to our earlier estimate.”
Whatever the oceanic equivalent of sticking a finger in the air is, this is surely it. I am willing to listen to your explanation as to why this study is thought to be so acurate when it is based on such adjusted data and the authors are saying their first go had flaws in it.
Tonyb
George E smith 11 37 51
Yes. Surely you have hit several nails on their respective heads.
Tonyb
Not an easy article for me to follow (I am not a scientist), but I can agree with Dr. Quirk’s conclusion that satellites would be the better measuring stick for atmospheric temperature anomalies than ground-based stations. The ground-based stations, because of the way they currently are so oddly and poorly placed by NOAA’s own standards (kudos to you, Anthony, for pointing that out to all of us on a daily basis), add just way too many additional variables to make me believe that they can properly adjust the measurements to compensate adequately for these additional variables.
Mike Jonas
You replied to my post;
TonyB (01:32:21) : “A 140% error was mentioned. Surely you can’t possibly begn to accept data with this degree of error.”
With your comment
“It’s a high % only because it’s relative to a low figure. “0.1 +- 0.14″ is IMHO a better way of expressing it. It does tell you that the actual rise is unlikely to be over 0.24 or under -0.04 – still useful information.”
Mike, It may still be useful information but its different information 🙂
TonyB
This has filled in a lot of my understanding of the differences in the four series, and explained why I always got an uneasy feeling about the data. This has confirmed my suspicion that despite or because of the manipulation the errors would be bigger than the slope of the overall trend, and that is indeed the case. Thank You.
sky (15:14:47) :
Then by all means please prove them wrong and publish the analysis!
>What happened to the fifth data set; that of NCDC/NOAA?
This was an attempt to discredit GISS. Given NCDC and GISS are very similar and HadCRU is the outlier at the surface including NCDC would have blown the story.
“Sceptic” science at work.
“Of course in Jan 2001 it was reported that ocean buoy measurements made at a fixed depth of one metre in the water, and a fixed height of three metres in the air showed that the water temperatures and the air temperatures are not correlated”
Reported by whom, and where?
There is a debate going on between two of the bigger blogs out there: Jim Manzi at the Corner and Patrick Appel at the Daily Dish. Appel makes the following comment that is not disputed by Manzi, and I was wondering if anyone here cared to comment:
“It is just absurd to claim that “the Earth has actually been cooling for the last 7 or 8 years” when the 2010s will easily be the hottest decade on record (see “Very warm 2008 makes this the hottest decade in recorded history by far“). Also, the warmest year on record was 2005, according to the U.S. temperature dataset that best measures total planetary warming, the one from NASA’s Goddard Institute for Space Studies (see here)”
http://corner.nationalreview.com/post/?q=ZDExMTcyNDA4NzU0ODYyMDNlZGI5YjIyOTY0YTc3YzI=
debate (16:49:13)…………continuing from Francis(14:12:52)….NewScientist:
It is possible that the NASA approach underestimates the rate of warming in the Arctic Ocean, but for the sake of argument let’s assume that the Hadley record is the most accurate reflection of changes in global surface temperatures. Doesn’t it show that the world has cooled since the warmth of 1998, as many claim.
Not necessarily. The Hadley record is based only on surface teemperatures, so it reflects only what’s happening to the very thin layer where air meets the land and sea.
In the long term, what matters is how much heat is gained or lost by the entire planet – what the climate scientist’s call the “top of the atmosphere” radiation budget – and falling surface temperatures do not prove that the entire planet is losing heat… …
…The reason is that the outer atmosphere, the stratosphere is cooler because we’ve added more “clothing” to the lower atmosphere in the form of greenhouse gases like carbon dioxide…
…As a result, the planet is gaining as much heat from the sun as usual but losing less heat every year as greenhouse gas levels rise…
…How do we know? Because the oceans are getting warmer…
.
John Finn (08:37:06) : “If the oceans are indeed cooling then it will eventually become evident in the surface and satellite record.”
Yes.
“You refer to Roger Pielke. My understanding is that Roger says the oceans are “not warming” which is not necessarily the same thing as “cooling”.”
The difference is in the time period. Cooling from 2006. No net warming from 2003.
http://climatesci.org/2009/01/07/sea-level-budget-over-2003%E2%80%932008-a-reevaluation-from-grace-space-gravimetry-satellite-altimetry-and-argo-by-cazenave-et-al-2008/
George E. Smith (11:37:51) : “It seems to me that the earth’s surface is the primary source of the emitted long wave IR radiation; not the atmosphere; so it would seem that surface temperatures are what should be measured; not air temperatures.
So that makes all the oceanic water data, and all the land based air data; to be somewhat meaningless.”
Not so. As I explained in an earlier post, global warming is all about the imbalance between incoming and outgoing heat, and hence total heat content. Total heat content cannot be obtained from atmospheric or surface temperatures (land or ocean) because they are not measuring heat content of the main heat body. The main heat body wrt climate is the ocean.
Philip Johns (13:00:00) : “Levelling off? Maybe. Cooling? nope. Besides, it would take a long, steep and sustained cooling trend to lose all that heat gained since 1955”
I have no idea how reliable your linked NODC graph is, compared with other studies. I would agree with your interpretation of it. You would get the same from the Willis and Leuliette papers that I referenced in an earlier post. However, the Cazenave and Loehle papers clearly show cooling in recent years. Take your pick. As Pielke pointed out, the IPCC computer models are invalidated if non-warming occurs for more than about 4 years (net cooling is not needed to invalidate the models).
The Cazenave paper is linked in the climatesci.org link (reply to John Finn above). The Loehle paper can be downloaded from http://www.ncasi.org/publications/Detail.aspx?id=3152 .
It has taken us 30 years to acquire the “heat gained since 1955“. You can’t expect to lose that much in 3 or 4 years.
Frederick Michael says:
Using it for ammo will only show ignorance of how the two gases behave in the atmosphere. CO2 is a long-lived greenhouse gas that builds up in the atmosphere in response to fossil fuel emissions. By contrast, humans cannot currently emit water vapor on a scale that significantly influences its concentration in the atmosphere. The concentration of water vapor is essentially controlled by the temperature. It is only by raising temperatures through an increase in CO2 concentrations that humans can indirectly raise the level of water vapor in the atmosphere.
These scientific facts are often summarized by the statement that water vapor is a feedback, not a forcing.
PaulHClark says:
No…It just states the obvious, which is that when you have a system that has fluctuations superimposed on a long-term trend, one cannot accurately determine the trend without a long enough series of data.
debate (16:49:13) :
There is a debate going on between two of the bigger blogs out there: Jim Manzi at the Corner and Patrick Appel at the Daily Dish. Appel makes the following comment that is not disputed by Manzi, and I was wondering if anyone here cared to comment:
“It is just absurd to claim that “the Earth has actually been cooling for the last 7 or 8 years” when the 2010s will easily be the hottest decade on record (see “Very warm 2008 makes this the hottest decade in recorded history by far“). Also, the warmest year on record was 2005, according to the U.S. temperature dataset that best measures total planetary warming, the one from NASA’s Goddard Institute for Space Studies (see here)”
http://corner.nationalreview.com/post/?q=ZDExMTcyNDA4NzU0ODYyMDNlZGI5YjIyOTY0YTc3YzI=
____________________________
Hi debate:
They quote the GISS Surface Temperature (ST) average for the past decade, which says nothing about the trend within that decade, up or down. The current decade is near the top if a cyclical temperature curve so its average will tend to be high, compared to past and future decades.
As I and others have said, it is wrong to take the tangent to an arbitrary point on a cyclical curve, erroneously assume linearity, and then project that linearity far into the future. THAT is absurd.
Also, they are relying on ST data without allowing for the ~UHI (etc) effect of ~0.07C per decade, as described further below.
2008 was about the same average global temperature as 1940, according to the first graph at
http://www.iberica2000.org/Es/Articulo.asp?Id=3774
(using Hadcrut3 ST data for 1940 to 1979 and superior Lower Troposphere LT data from 1979 to 2008).
You can also see the cyclical nature of Earth temperature from this graph, since it covers ~one complete PDO Cycle.
Note the divergence in ST and LT data over this ~30 year period to 2008 is ~0.2C, or 0.07C per decade. This is a reasonable measure of ~UHI effect (Urban Heat Island, land use changes, etc. etc.)
But my above statement that 1940 and 2008 exhibited similar average temperatures does not account for 4 decades of ~UHI effect in the Hadcrut3 ST data, so we can deduct another ~0.3C from the ST record from 1940 to 1979.
Therefore, it is reasonable to suggest that 1940 was ~0.3C warmer, on average, than 2008.
Where’s the global warming?
A few other points:
Since 1940, humanmade CO2 emissions have increased ~800%, and there has been no net global warming.
Where’s the temperature sensitivity to increased CO2?
CO2 lags, does not lead, temperature at all known time scales. By saying CO2 drives temperature, one is in effect saying that the future is causing the past.
Where’s the logic?
Where’s the beef?
_________________________
Steve (Paris) says:
Boy, Bailey (the author of that Reason article) has badly garbled Orszag’s testimony, which is available here: http://www.cbo.gov/ftpdocs/92xx/doc9276/05-20-Cap_Trade_Testimony.1.1.shtml or, better yet the original CBO study that it was based on here http://www.cbo.gov/doc.cfm?index=2104&type=0&sequence=4 , you find that the numbers quoted are only the numbers for the costs due to the increases in the price of energy but ignore the fact that the selling of the allowances generates a lot of revenue, which can then be returned to the households in various ways. How it get returned determines the ultimate effect on the households but the net cost, what they call the “substitution cost” averages only ~$100 per household, roughly an order of magnitude less than those scare-values given.
To understand this best, look at Table 4 here http://www.cbo.gov/doc.cfm?index=2104&type=0&sequence=4 which shows more-or-less the values that Bailey quotes [I think they are a little different because of some updating to 2006 constant dollars]; this table gives the costs associated with the increase in energy prices without factoring in the revenue generated from the sale of the allowances. Then compare this to Table 5 which shows what would happen for various scenarios of how the allowances are allocated and the money from them returned. For example, with the most progressive plan shown of an auction of allowances with a lump-sum rebate, the bottom quintile actually has an INCREASE in their after-tax income by 1.8%. The second quintile also comes out ahead. The top three quintiles have a decrease in after-tax income although even for the top quintile, the amount is only -0.9%.
Well, the problem seems to be that there are a lot of people who are badly misrepresenting the costs to them as Bailey did. (I won’t say “lying” because it may have been an honest mistake on Bailey’s part. The subject is confusing and even Orszag’s testimony, although it sort of explains it, doesn’t make it as clear as the original CBO study.)
Joel Shore (20:07:32) : I think most people would prefer to keep their $680 to $2,180, than rely on it being “returned to the households in various ways” and not disappear into Washington and the green machine. And if it is going to be returned to them, there doesn’t seem to be a lot of point in taking it from them in the first place.
It certainly IS interesting to see that the actual data shows no warming. If you dive deeper into the rabbit hole, you will see that it even shows COOLING. Around 1975, scientists were panicked about another ice age. Then they were shouting warming….and now cooling again!
Thanks for posting.
Some of the anomalies noted aren’t even anomalies at all. The problem with the temperature’s anomalies don’t take all into consideration. When in 1957 the start for the analyse of water in Lake Vaettern’s watersystem down to the Baltic Sea started, one of the analyse parameters was temperature, others were Ph-value, visibility down in lake/river etc, biologic analyse and chemical analyse of watercontent etc. For the temperature analyse three values were needed: One in air aprox. 2 meters above waterlevel. One 2 meter down from waterfront in the lake/river etc. the last reading each time was from 2 meters above the ‘seafloor’ in lake/river tested.
Now there were two observations that have stringens for other temperature readings around our world. The oceans and lake systems represent more than 70% of the Earth’s surface. When measuing above water or in water 1-2 meter down there always are ‘anomalies’ when ever the surface of water saw ‘fresh’ water. In other words during or after rain the temperatures always showed anomalies from what’s expected due to earlier readings. Secondly the wind speed as well as the speed of waterstream weren’t a constant factor thus that too could have an impact.
As for the 12 years series shown above I just wonder which mean been used? I have looked closer into mean values measured on land and I have seen so called scholars using different means in same study to make their case 🙂
Mike Jonas (19:03:08) :
Yes.
The difference is in the time period. Cooling from 2006. No net warming from 2003
What happened between 1975 and 1985 then? Clearly there was no increase in OHC, but that didn’t stop air temperatures rising, and it didn’t a significant 20 year increase in OHC in the Post-1985 period.
You’re calling this ‘result’ far too early. I realise you’re desperate for evidence which contradicts AGW, but that is some way off yet. As for “cooling since 2006” you’ll be telling us next it’s been cooling since last week.
The analysis for the last ten years[ rather than 1997-2008 is also similar
LEAST SQUARES TREND LINE SLOPES GLOBAL TEMPERATURE ANOMALIES LAST TEN YEARS – 1999-2009
GISS 0.01868 C/year
UAH 0.01212 C/year
RSS 0.01048 C/year
CRU 0.00721 C/year [hadcrut3]
COMPOSITE 0.01198/year [WOOD FOR TREES Temperature index]
All these temperature anomaly trend line slopes went negative or starting to show cooling trend starting in 2001 or the last 8 years as shown below
GISS -0.001360 C/year
RSS -0.001588 C/year
UAH -0.013737 C/year
HADCRUT3vgl -0.012197 C/year
The interesting note about the HADCRUT 3 figure is that it is almost identical to the slope for the period 1900-2009, namely 0.00727 C/year , so where is all the global warming that AWG science claims?.
I think it is wrong to accept that extra global warming or cooling as a trend must last for 30 years or that we need that many years to declare a long term trend .These climate cycle durations are all over the place and 30 years is not the norm.
Extra Global warming lasted only about 13-14 years from 1994-2008 and is no longer happening. Similar warming took place in the period 1926-1944 .Global warming started to decline in the oceans in 2000 and atmospherically in 2001 as measured by least squares trend line slopes.