A Quick Note from Kip Hansen
A quick note for the amusement of the bored but curious.
While in search of something else, I ran across this enlightening page from the folks at UCAR/NCAR [The University Corporation for Atmospheric Research/The National Center for Atmospheric Research — see pdf here for more information]:
“What is the average global temperature now?”
We are first reminded that “Climate scientists prefer to combine short-term weather records into long-term periods (typically 30 years) when they analyze climate, including global averages.” As we know, these 30-year periods are referred to as “base periods” and different climate groups producing data sets and graphics of Global Average Temperatures often use differing base periods, something that has to be carefully watched for when comparing results between groups.
Then things get more interesting, in that we get an actual number for Global Average Surface Temperature:
“Today’s global temperature is typically measured by how it compares to one of these past long-term periods. For example, the average annual temperature for the globe between 1951 and 1980 was around 57.2 degrees Fahrenheit (14 degrees Celsius). In 2015, the hottest year on record, the temperature was about 1.8 degrees F (1 degree C) warmer than the 1951–1980 base period.”
Quick minds see immediately that 1.8°F warmer than 57.2°F is actually 59°F [or 15° C] which they simply could have said.
UCAR/NCAR goes on to “clarify”:
“Since there is no universally accepted definition for Earth’s average temperature, several different groups around the world use slightly different methods for tracking the global average over time, including:
NASA Goddard Institute for Space Studies
NOAA National Climatic Data Center
UK Met Office Hadley Centre”
We are told, in plain language, that there is no accepted definition for Earth’s average temperature, but assured that it is scientifically tracked by the several groups listed.
It may seem odd to the scientifically-minded that Global Average Temperature is measured and calculated to the claimed precision of hundredths of a degree Celsius without first having an agreed upon definition for what is being measured.
When I went to school, we were taught that all data collection and subsequent calculation requires the prior establishment of [at least] an agreed upon Operational Definition of the variables, terms, objects, conditions, measures, etc. involved.
A brief of the concept: “An operational definition, when applied to data collection, is a clear, concise detailed definition of a measure. The need for operational definitions is fundamental when collecting all types of data. When collecting data, it is essential that everyone in the system has the same understanding and collects data in the same way. Operational definitions should therefore be made before the collection of data begins.”
Nonetheless, after having informed the world that there is no agreed upon definition for Global Average Temperature, UCAR assures us that:
“The important point is that the trends that emerge from year to year and decade to decade are remarkably similar—more so than the averages themselves. This is why global warming is usually described in terms of anomalies (variations above and below the average for a baseline set of years) rather than in absolute temperature.”
In fact, the annual anomalies themselves differ one-from-another by > 0.49°C — an amount just slightly smaller than the whole reported temperature anomaly from 1987 to date (a 30-year climate period). [The difference between GISS June 2017 and UAH June 2017].
So, let’s summarize:
- We are told that 2015, the HOTTEST year ever, was …. what? ….. 59°F or 15° C – which is not hot except maybe in the opinion of the Inuit and other Arctic peoples — which may be a clue as to why they really talk in anomalies instead of absolute temperatures.
- Although a great deal of fuss is being made out of Global Average Temperature, there is no agreed upon definition of what Global Average Temperature actually means or how to calculate it.
- Despite the problems of #2 above, major scientific groups around the country and the world are happily calculating away on the as-yet undefined metric, each in a slightly different way.
- Luckily (literally, apparently) the important point is that although all the groups get different answers to the Global Average Surface Temperature question – we suppose it’s because of that lack of an agreed upon definition of what they are calculating — the trends they find are “remarkably similar”. [That choice of wording does not fill me with confidence in the scientific rigor of the findings — it so sounds like my term – “luckily”]. Even less reassuring is being told that the trends are “more [remarkably similar] … than the averages themselves.”
- And finally, because there is no agreed upon definition of Global Average Temperature and the results for the undefined metric from varying groups are less [remarkably] similar than the trends; even the calculated anomalies themselves from the different groups are as far apart from one another as the entire claimed temperature rise over the last 30 year climatic period.
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Author’s Comment Policy:
Although some of this brief note is intended tongue-in-cheek, I found the UCAR page interesting enough to comment on.
Certainly a far cry from settled science — both parts by the way — not settled — and [some of it] not solid science.
I’m happy to read your comments and reply — but not to Climate Warriors.
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Now I’m really confused 😉
Thank you (as always), Kip.
“I believe that climate scientists put decimal points in their forecasts to show they have a sense of humor.”
H/T William Gilmore Simms
An average is not necessary. Think more in terms of an index such as the Dow Jones, or S&P500 stock indexes. It does not matter what the number is when finding a trend, it only matters that the index is consistently calculated the same way each time it is calculated.
I’ve been a science geek all my life with hobbies ranging from astronomy to ornithology, so initially I took the climate scientists at face value. Then I stumbled into Climate Audit and WUWT, and was blown away by the politics and deceipt.
It’s very unfortunate that such a new and promising scientific field was hijacked by politicians and ideologues. Caution, skepticism and moderation are no match for fear and paranoia. But I think we’ve passed peak hysteria, even if the politicians and media will refuse to let go.
If the earth approximates to a black body or is even remotely close to it are all the photographs of it from space shown by NASA faked in a studio or photoshopped?
The first (and only) time I ever looked at all 40 or so of the CMIP models, I made the “mistake” of calculating absolute temperatures rather than anomalies. I was astounded to note that the different models varied by about 3 degrees C in their baseline absolute temperature for their starting year (1880, I think). Now consider two models differing by 3 C. Each model will include some areas of the globe that are below the freezing point of water, but one will have a much higher area of ice than the other, affecting estimates of albedo, etc. So that alone would lead to major changes in how well each model matches reality. Since all models are tuned, each will adopt a different method of tuning in order to match historical records. So we would see some more or less arbitrary choices of aerosols, clouds, and other items of great uncertainty in order to make the fudge factors work.
Well at least they didn’t try to report it to 0.01.
Well look to how religions in the past reconciled the contradictory, vague and deceptive aspects of their various scriptures and dogmas.
The climatocracy are doing much the same.
Who wants to get rich beyond their wildest dreams ?
Invent an a/c compressor that isn’t so loud/annoying that the cicadas compete with the noise.
Independent of incomparable baselines, the global anomalies aren’t fit for purpose for a basic reason, inadequate coverage. This is true for land only, where large swaths of Africa, South America, and northern Eurasia either have no data or no long term data. The same is true except moreso for yhe oceans in the pre float/Argo era. Best would be to create a Dow Jones like global index of good, well maintained stations with long records. For example RutherGlen Ag and Darwin in Australia, DeBilt Netherlands, Sulina Rumania, Armaugh Ireland, Hokkaido Japan, Lincoln (University station) Nebraska, Rekjavik Iceland, Durban South Africa. Note not all are GHCN. No homogenization. Perhaps coverage area weighted. That way one has a land record unbiased anomaly trend. Why has this not been done? I suspect because it would show little or no warming, just like each of the named candidates for the index..
When will the next “base” period be defined and used?
Is global average temperature a meaningful concept? A bit like averaging all the numbers in the phone book – only one phone will answer.
these 30-year periods have no scientific meaning or value , this period cam about because it was hopped that given this long the failure or reality to match models regards the relationship CO2 and temperature increases would be overcome by a change in reality .
It simply has no meaning , no value , no validity other than as a political tool . It could have easily been 40 or 35 years without making any difference at all .
It is indeed a classic example o the area where numbers are picked out of thin air and whose only value comes there perceived impact in supporting ‘the cause ‘
Great news. The world’s average temperature is 15 degrees, and that is the hottest the world has been since the industrial revolution began. Global warming? Still a bit chilly isn’t it? Where’s Josh with an appropriate cartoon?
“In fact, the annual anomalies themselves differ one-from-another by > 0.49°C —”
Apologies for not being to put up the plot now but it would be good to see a moving SD for 120 months of differences. Places like Argentina ( hardly a backwater in the early 20th C) has only data for Buenos Aires until 1960. Surely the different methods mean that the spread of differences decreases with time?
How dare you guys sending the hockey schtick Mann to oz , can’t you keep him over there somehow , we have enough fake scientists here already .
In geological time scales we are discussing in this post an indiscernible rise in temperature at a time we should be warm anyway. Carry on.
Kip, that’s for starters. When they systematically through an algorithm keep changing the past data, both their global temperatures and anomalies of previous base periods have a life of only one month. As Mark Steyn said at the Senate Committee, how can one consider what the temperature will be in 2100 when we still don’t know what it will be in 1950! This means even their models are tuned to something that doesn’t exist anymore.
Standard day sea level definition = 59 deg F / 15 deg C, 1013 millibars / 14.2 psi.
Thanks! Interesting article
But is it not the same with so much in climate science.
Just testing to see how long before this comment is deleted.
Worse than we don’t know the present temperature, the pre-industrial temperature is more uncertain. We are told by COP21 we should not exceed 2 C above pre-industrial temp. But the best temperature record has a range of 7 to 10 C. 3 degrees spread is greater than the target 2 degrees. And no SST data. The uncertainty is unknown. They have no idea what absolute temperature they are aiming for.
http://blogs.nature.com/news/files/2012/07/berkeley.jpg
I was taught that an operational definition is a definition of a term in a manner so explicit that all persons applying the definition as a criterion for identifying something would come to exactly the same conclusion as to whether or not the definition applies in any particular instance of it’s attempted application.
In empirical science an operational definition of a quantity is a definition that references the complete, replicable process for quantifying the result of the operation. This, in principle, allows separate investigators to apply the same process to the determination of a quantity and to directly compare their results. For example, ‘temperature’ can be measured by a process that involves the comparison of voltages between two thermocouples, one of which is in thermal contact with the object of interest and the other is in contact with a specific medium of precisely known reference temperature.
Logically an operational definition identifies a well-characterized parent group to which a term belongs, along with necessary and sufficient criteria to distinguish it from all other members of the same group. For example, to define ‘sanguine’ as ‘the color of blood’ identifies the parent group (‘colors’) and provides a criterion (‘is your color the same color as blood?’) that clearly distinguishes it from other members of the parent group.
The important point of an operational definition is that it completely removes all individual variation among observers from the exercise.
Harson:
I have previously criticized you for trying to be a ‘jack of all trades’ writer,
covering too many subjects to be an expert in all of them.
I particularly criticized your article on obesity where you claimed
calories didn’t matter — something fat people love to hear!
To demonstrate that I have nothing against you, and only judge
what you write:
I can’t tell you how disappointed I am after reading this article,
and finding it was better than a related post I made on my climate change blog:
http://elonionbloggle.blogspot.com/2017/08/total-confusion-on-absolute-mean-global.html
I congratulate you on a good article, and selecting a far too often forgotten subject:
What is the absolute mean global temperature?
A secondary question, ignored just as often, and perhaps a subject for your next article, is:
How can one number represent the ever changing climate on our planet?