Guest essay David Archibald
We all know that Santa’s workshop is somewhere in the Arctic, producing toys for the world’s children. Also north of the Arctic Circle is Professor Humlum’s office at the Unversity of Svalbaard wherein he toils each month to update a report on climate. The first chart in that report is the UAH temperature for the lower troposphere, copied following and annotated with lines showing the evident trends:
Figure 1: UAH global temperature anomaly
In the period from 1978 to 2015, the lower bound of the record is shown by the orange line. Then there was a period of a couple of years in which the temperature anomaly was in a narrow, steep uptrend channel. The temperature anomaly broke up from that channel due to the 2016 El Nino.
Since that 2016 El Nino, two parallel upper bounding lines have formed, in downtrend. The lower green one is formed by six points. The upper red line is formed from only two points – the minimum to make a line – but is notable in that it is parallel to the green line. So climate isn’t a randowm walk. There is some physical process that limits how far temperature excursions go.
The uptrend from the beginning of the satellite record in 1978 to 2015 was 0.4°C over 36 years. That equates to 0.000926°C per month. If we take that amount from each monthly temperature anomaly, cumulatively, we produce the following graph of the detrended monthly temperature anomaly distribution from 1978 to 2015:
Figure 2: UAH global lower troposphere temperature anomaly detrended monthly distribution 1978 to 2015
What is apparent is that the detrended temperature anomaly distribution is nearly symmetrical. The temperature likes to stay in the middle of the band. The only excursion from the 0.8°C wide band was for the 1998 El Nino.
Does the temperature record to date tell us anything about what will happen from here? A better chart for that is the NCDC global temperature anomaly, also from Professor Humlum’s update for November:
Figure 3: NCDC global temperature anomaly 1979 to 2022
The uptrend channel 0.8°C wide to 2015 is well defined with the orange upper and lower boundaries absolutely parallel and rising at 0.011°C per annum. Since the 2016 El Nino the trend is now down in a tighter, steeper trend channel that is 0.5°C wide and falling three times as fast at 0.036°C per annum.
From this downtrend, can we say that the Modern Warm Period is over, that global warming is definitely over, dead and buried, when the current downtrend regime takes us below the lower bound of the previous uptrend channel?
That could happen as soon as 2025 if the temperature anomaly stayed within its new downtrend channel. Sooner than that would be better for the world (since global warming is a bad thing, the corollary is also true – the faster it gets colder, the better). But it would be scientifically gratifying if the temperature trend stayed non-random in achieving what we want.
Either way, blessed release is coming.
David Archibald is the author of American Gripen: The Solution to the F-35 Nightmare