Remark_1: a PDF of this draft has been added to this discussion to allow the readers to have access to the hyperlinks.
Remark_2: this discussion is aimed at drawing attention to the seriousness of the current man-made global warming in which science has much to do in order to avoid the uncertainty spreading.
Last November 17 and 18 a very concerning fact took place for the first time in modern recorded history. The global surface air temperature exceeded in 2-degree Celsius the pre-industrial average temperature taken between 1850-1900 prior to extensive and widespread use of fossil fuels. Despite scientists assure that the observed exceeding, that happened for a limited number of days, does not mean that the Paris Agreement targets are already compromised, it is urgent and mandatory to keep a precautionary tracking of the atmosphere to dilucidated if a threshold is gaining momentum pushing the atmosphere to start working around the 2-degree Celsius atmospheric overheating, and becoming the main feature of the anthropogenic climate warming within the next ten years.
What happened last November 17 is a serious issue that cannot be overlooked nor discarded by the irresponsible "optimism" which tells things will get better because of technology-based fairy-tales, and by the institutional denialism that exist around the seriousness of the human-sparked global warming and all that has to do with its speed (or if you prefer, its rate of advancement). For those reasons, a conservative perspective will not be helpful keeping in mind the last twenty years trends in CO2 global emissions.
As expected, COP 28 was unable to leave behind its 1.5-degree Celsius goal as nothing serious is taking place with regards how fast the human-boosted warming is going to exceed the 2-degree Celsius above pre-industrial average.
Almost in parallel, the tipping points narrative has been warning humans cannot exceed the 1.5-degree Celsius, despite it is being also said that humans are "near climate tipping points". The bad news is humans still have not developed the hard models and measurements to obtain an accurate metrics of who far humans are to reach that tipping points. Furthermore, the "tipping points" discourse is too vague, and it is becoming another meaningless concept that too many in the world talk about, without having yet available any measurable parameters nor a quantifiable perception of those potential thresholds.
For decades it has been told that remote sensing and all that comes from Earth Observation (EO) systems would help to achieve a sustainable path while planning for a sustainable development (SD), and for a tough future under severe climate strikes. Tonnes of papers using satellite-provided data have been published and, no doubt of it, will keep a high rate of publishing being, so far, unable to show evidence of an overall improvement of the global situation as human dynamics seems unstoppable.
Despite the lack of a decisive global and integrative climate action will persist as one of the main features and drivers of the international system in the near term, to start thinking about implementing a global coverage alert system to inform globally when and how often the global mean Earth temperature gets closer or exceeds the 2-degree Celsius above pre-industrial average. That alert system should also have a straightforward design to display the information to obtain trends (the speed of atmospheric overheating is crucial) and frequency of that events.
That alert system should be very "sonorous". It does mean it should, among other means and devices, reach the cell phones of the people in a similar way as, for instance, earthquakes alarm systems work. In few words, each time the global mean temperature gets closer and/or exceeds the 2-degree Celsius above pre-industrial average people must know.
To make concrete progresses concerning the sense of urgency and the situational awareness among global citizens, to end with the self-deceiving attitude that can be witnessed not only in rich but middle income and poor countries too. The warming is being faster than predicted and expected. Humans lost this war twenty years ago when it was, finally, accepted that the warming was faster the previously accepted. Unfortunately, despite the huge amount of data, and the quantity of satellites orbiting Earth, it is rather an impossible task yet to provide any measure of that speed and nor agree on how humans should measure that rate of change.
It is time to end the over discussing time and get serious. It is quite advisable to carry out a sustained observing effort on what is going on in Brazil and in the middle of the Amazonia, while following the situation over there all along the summer 2023 in the Southern Hemisphere. It is important to be able to know how many times it could happen during the next six months.
It is also advisable that science make its best effort in avoiding publishing papers that provide grounds for time ambiguity. It should be a mandatory attitude to be quite clear in validating the scope and conclusions of any paper in concrete time-frames. To leave the door open for speculation regarding the timing that can be inferred from those publications exerts a very negative impact in all that pertain to figure out the right time scales for climate action globally speaking.
An explicit acknowledgment of what version, the weak or the strong, of the sustainable development (SD) concept is being framed as the main analytical tool is a complementary publishing strategy that could be of great assistance when evaluating the reach and strength of the conclusions. It is worth mentioning that the “weak” version has been adopted for so long and can be the explanatory root for the aggregate failure of both, to accomplish higher levels of sustainability and give shape to the urgent human collective self-restrain to ameliorate the response to the climate and ecological crisis.
Science is not free of being submitted to any governance regime which should be vigilant of the undesired and counterproductive effects of scientific papers on the political process that, regrettably, took the control of all that concerns to the climate discussion, and the institutions designed to institutionalize a, supposedly thought, collective action.
The bottom line is nineteen years have been lost. In December 2015 it was projected the world would reach the 1.5-degree Celsius by March 2045. Reassessed estimations are suggesting the world risk breaching that benchmark by February 2034.
Remark_3: as always I am willing to build network capabilities aimed at publishing papers with policy-implications, participate in workshop, and/or find the paths for setting the structure of a good well-funded research project.
The document in your hyperlink says: "ERA5 data also reveals that on 17 November the global surface air temperature was 1.17°C above the average for the 1991-2020 reference period."
In the Excel spreadsheet (also available through the hyperlink)
# temp: is defined as 'Daily mean absolute temperature based on hourly values from 00 to 23 UTC'.
Could you please demonstrate specifically how the Daily mean absolute temperature was calculated using hourly values? And how was the annual average surface air temperature calculated using these daily averages?
For example, was the Tday average=(Tmax day +Tmin day)/2 for each day, and then, the annual average surface temperature calculated as (T day 1 av +Tday 2 av +...)/365?
Or another method was used?
Thanks.
Good morning/afternoon/evening Alexander,
Good questions you pose indeed.
All of them has to do with internal (I do also suppose agreed) methodologies within COPERNICUS. Therefore, I could, of course, explore more on that and try to provide an answer to you.
The bottom lines here are threefold (at least):
(1). Why to understand the atmosphere warming is so debatable and subject to academic exchanges discussions on methodologies...? (That is being witnessed since the last twenty years without any decisive climate action yet...).
(2) Why humans have such amount of troubles to measure with accuracy a key parameter in all that has to do with an unprecedented human-made mess...?
(3) Why almost everyone is spending such amount of energy in a "sophisticated" way of denialism, as far as the precautionary perspective that should guide us keeps failing to be adopted in all in terms of a faster warming that expected, and more importantly, "desired" to keep business-as-usual and aggregate human life-style as usual as well.
Thank you for your questions... Be sure I'll do my homework.
Regards,
Hernan L.
Hernan L. Villagran Thank you for your reply. Please do your homework and answer my questions. There is a reason why I asked these questions. There are serious implications that depend on the answers.
At the same time, I am surprised that so many average temperature calculation results are published (be it within Copernicus or numerous other sites) without a clear understanding of how the temperature averaging was performed from the local stations' temperature measurements in the first place.
In addition, these are a few comments regarding your threefold bottom lines:
(1) You write "Why to understand the atmosphere warming is so debatable and subject to academic exchanges discussions on methodologies."
Keep in mind that scientific methodology is always of paramount importance for the validity of conclusions. Mathematically and physically unjustified methodology leads to wrong/unsubstantiated conclusions. In fact, my questions about how the temperature averaging was performed are questions about methodology.
(2) You write "Why humans have such amount of trouble to measure with accuracy a key parameter". Measurement accuracy of the key parameter (I believe that you imply the key parameter is temperature) and ensuing calculated average temperature error MUST always be reported with results to make them scientifically valid.
(3) " .....all in terms of a faster warming than expected.."
Expected by whom and on what basis? On the basis of various climate models? On the assumption that the planet Earth is a thermostat that must be kept at a constant temperature? On the assumption that a critical warming rate exists and, if exceeded, it results in a global disaster?
Please clarify these points.
Alexander Kolker I imagine that the Daily mean absolute temperature was calculated from the hourly values by summing them and dividing by 24. The annual average surface air temperatures were calculated by summing the daily temperature and dividing by 365 or 366 for leap years.
What are the serious implications that this answer produces?
Alastair Bain McDonald Your imagination took you too far. Instead, it would be better to take a look at the document that is accessible using the Copernicus hyperlink. According to Copernicus documentation
https://confluence.ecmwf.int/display/CKB/ERA5+explorer%3A+documentation#ERA5explorer:documentation-Long-termaverage(referenceperiod)
the typical/average temperature values displayed are calculated by finding the monthly mean of different daily temperature statistics, and then averaging each monthly mean over multiple years to produce a ‘normal’ baseline. Keep in mind that an average temperature cannot be directly measured. The average can only be calculated. And the averaging method is not unique. Indeed, the statistics displayed are as follows:
― Monthly average temperature – the mean of all six-hourly (daily) temperatures which fall within the given calendar month, averaged over the 1981-2010 period or 1991-2020. This gives
t day average=(t day midnight +t day 6 am+t day 12pm +t day 6 pm)/4. This formula is used mostly in continental Europe.
In most Anglo-Saxon countries and some African and Asian countries, the Max - Min algorithm was, and is in use. The daily mean is calculated as
t day average=(t max+t min)/2.
It is known, that all these formulas give a different daily mean if compared to each other (see Limburg, M. ‘NEW SYSTEMATIC ERRORS IN ANOMALIES OF GLOBAL MEAN TEMPERATURE TIME-SERIES‘, Energy & Environment, 2014, v. 25, pp. 105-122). But which one is right? There is no possible correct answer. Since all of them do not have any physical meaning, this question cannot be answered by using the first physical principles. Therefore, it is a free choice following practical considerations. As long as the focus is the local daily temperature change and the same algorithm is always used it does not really matter. But as soon as the data needs to be combined to calculate a global mean, the magnitude of uncertainty introduced by different arbitrary formulas becomes important if one compares any average temperature anomaly derived from one daily formula to any other by blending them with each other (the procedure called now homogenization).
In the above paper, it is demonstrated that the combined error of the average global anomaly may lie within the limits 1.084 C to 2.084 C with 95% confidence. But this is by far not all. In addition, it may also be noted that the common error with all averaging methods taken into account is not equally distributed around the mean value of time-series anomaly because it has different magnitudes in plus or minus directions.
Thus, an anomaly mean calculation for the whole globe as done so far (be it 1.17 C for November or global 1.5 C or 2 C or any other value) using the current homogenization method does not allow making the conclusion for which it is intended for, i.e. demonstration that a little upward global temperature trend should be interpreted as a sign of global warming. The anomaly itself is hidden within this much broader band of uncertainty.
This is an answer to why the averaging method has so serious implications.
Take-away:
1. The systemic and unavoidable uncertainty in the calculation of the small upward trends of average global temperature anomaly applies to all organizations that produce similar data for global average temperature anomaly increase, such as NASA/GISS, NOAA, Hadley Center Climate Research Unit, Berkley Earth, et al.
2. No small-scale upward trend (or equally a downward or flat trend) of the global average temperature anomaly in the range 1 C to 2 C can be reliably demonstrated,
3. There are other serious issues with averaging local temperatures as intensive thermodynamic variables. These issues were not included in this post to keep it relatively short. They have been addressed in other posts and threads.
Dear Alexander Kolker
Don't you realise that you are using the arguments of a climate change denier. You are denying that an average temperature can be directly measured. But there are four groups making measurements which roughly agree and there is evidence from throughout the world that climate disasters such as droughts, wild fires, melting glaciers, floods and rising sea levels are occurring.
It is obvious to any sensible person that if we do not stop pumping CO2 into the atmosphere these disasters will increase in both frequency and intensity, The human suffering will be far worse that that which happened during the Holocaust with billions dying compared with the millions during the Holocaust.
Alastair Bain McDonald You did not provide even a single mathematical or physical counterargument to my post's content. Apparently, you are not familiar at all with the scientific basis of the subject you are talking about. Instead, you posted ignorant and scientifically illiterate typical political activists' empty slogans and fluff aimed at creating and promoting baseless fear that "the sky is falling". Shame on you for doing that. RG must NOT be a venue for political activists like you are.
And, yes, I repeat: an average temperature cannot be directly measured physically. It can only be formally calculated from the locally measured temperatures using one or another averaging method with unavoidable random and systematic errors that must be indicated to make any conclusion.
Alexander Kolker
I didn't claim the sky was falling. I argued that if we continue pumping CO2 into the atmosphere then the changes to the climate that we are seeing will become greater. That is simple logic which you seem to be denying.
In the case of global temperatures the number of measurements is so great that the error when they are averaged is insignificant. This is shown by the agreement between the six global temperatures which are published. One can be seen here: https://climate.copernicus.eu/copernicus-2023-hottest-year-record with markers showing the results of the other five.
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