+27 83 629-7690 henrypool7@gmail.com

This post is also available in Dutch,

About a decade ago, after seeing the movie “An Inconvenient Truth”, and noticing the ice melt in the Arctic, I was concerned that the theory of manmade global warming (AGW) is correct and indeed happening. Feeling a bit guilty about driving my big old diesel truck, and just to be sure, I considered that here [in Pretoria, South Africa] I could easily prove and confirm the theory. Namely the logic following from AGW theory is that more carbon dioxide (CO2) coming into the atmosphere would trap heat on earth. Hence, we should find minimum temperature rising, pushing up the average temperature. Here, in Pretoria, in the winter months, we hardly ever get any rain, but we have many people burning fossil fuels to keep warm at night. On any cold winter’s day that results in the town area being covered with a brown-greyish layer of air, viewable from a high hill outside town in the early morning. I figured that as the population increased over the past 40 years, the results of my analysis of the daily data [of a Pretoria weather station] must show minimum temperature rising, particularly in the winter months. Much to my surprise, I found that minimum temperatures here in Pretoria were falling, any month….

I first thought that somebody must have made a mistake: the extra CO2 was cooling the atmosphere, not warming it. That made sense to me as I knew that whilst there were absorptions of CO2 in the areas of the infra-red spectrum where earth emits [which would trap heat on earth], there are also the areas of absorption in the UV- and 1-2 um- and the 4-5 um range where the sun emits [which would send some heat to space].

Not convinced either way by my deliberations and discussions as a blogger on several websites, I looked at 10 other weather stations in the region to give me an indication of what was happening. In 2018 I updated the results of these 10 stations. They all have good daily data for the period 1977 – 2017, mostly. My own data were always obtained from tutiempo.net. The results are reported here:

summary of climate change south africa.xlsx (dropbox.com)

Strike 1:

My finding was that the ambient temperature in South Africa over the past 40 years had not changed, whereas, on average, minimum temperatures have dropped by 0.8K here.

Puzzled by my initial results, and still wondering about the ice melt, I decided to take a random sample of weather stations (ws) from all over the world. I ended up with 27 ws from each hemisphere that had good daily data going back 40 years. Being well trained in taking representative samples and looking carefully at my earth globe, I decided:

  • Equal number of ws in the northern and southern hemisphere.
  • As far as possible all ws balanced in latitude to 0 degrees or as close as possible to zero.
  • All ws distributed 60%/40% @sea / on land – this is representing the appearance of earth.
  • Always looking at the average change per year i.e., the derivative of the least squares’ equation.

The reasoning behind this sampling procedure was that I could minimize both the differences in height & light exposure and the differences in measurement methods between ws.

I conducted this investigation in 2015. Results include those of 2014. My results are summarized in the Table below. Original results were multiplied by 10 to show the results in degrees Kelvin per decade. Results for each of the 54 ws can be supplied upon request.

Table 1

Period: 1974-2014

Change in degrees K / decade






Southern  (27 ws)




Northern  (27 ws)




Balance on latitude

                                    15.82 degrees





My overall global result for the warming was 0.126 K/decade over the last 40 years and this was the same result as what Spencer and others had in 2015. This proves that my sampling method was good. However, my data set provided extra information about minimum temperatures that did not fit the theory of AGW…..

Strike 2:

My finding was that the ambient temperature in the southern hemisphere (SH) over the past 40 years had not changed much (0.017 x 4 = 0.07K). On average, minimum temperatures in the SH have dropped by 0.6K.

It appeared that the results I had obtained for the southern hemisphere were not even that much different than those I had found in South Africa.

Now what?

At some or other stage I came across the data from GISS LOTI. This is the global data set from NASA. Original data, see here

The figure below is a summary of all the data that they have from all the weather stations, January through to December, from 1960 until 2019, both in the NH and in the SH. Note the graphic on the bottom, showing the increase in warming versus latitude:


Warming against latitude

Strike 3:

The finding by NASA was that the warming of earth increases exponentially from 0 to +90 degrees latitude.

60 to 70% of earth is water. It would therefore be interesting to see what the warming rate is in the water around the world. The data set most often being used for the sea surface temperature is HADSST3.

 Wood for Trees: Interactive Graphs

Carefully looking at the above graphs, we can get a reasonable accurate estimate of the rate of warming over the past 50 years. It is ca. 0.17K/decade in the NH and about 0.09K/decade in the SH. In the water around the ‘Hoek van Holland’ they measured 0.30K of warming per decade since 1970. See here  According to this report:  Sea Surface Temperature (noaa.gov) it appears that the rate of the warming of the Arctic ocean at the highest latitude is now about 0.7K/decade.

I am a bit confused as to what happens in Antarctica. It appears that the surface of ice is growing, and it is also getting cooler when measured 2 meters above the ground. See here: https://breadonthewater.co.za/2021/04/05/unexpected-ice/

 However, it is claimed that there is still net ice loss, as measured by the satellites. I am doubtful about these results, as I wonder how they calibrated their equipment to ‘measure’ the original thickness of ice. See also further analysis by an independent party shown further down. Never mind that controversy, let us assume that at least half of the warmth as measured in the SH has arrived in and around Antarctica and is removing some ice there from the bottom.

The results of the warming of the seas and oceans are summarized by me in the Table below (to find the origin of the result you can click on it) :

Table 2


Change in degrees K / decade


  Period Result
-90 (my own estimate) 1970-2021 0.045
-90 to 0 (average) 1970-2021 0.09
  0 to 90 (average) 1970-2021 0.17
+52 (North Sea -@HoekvanHolland) 1970-2021 0.30
+58 (Baltic Sea) 1993-2020 0.53
+90 (Chukchi Sea) 1982-2017 0.70

Strike 4:

As before, my finding here is that the warming of the oceans is directly related to latitude. The lower the latitude the lower the warming rate.

Despite most of the innumerable glaciers worldwide retreating, one of the few unusual glaciers that maintains in a state of equilibrium is the large Perito Moreno Glacier because it continues to accumulate mass at a rate similar to that of its loss.[1] The reason remains debated by glaciologists.[2] See here: https://en.wikipedia.org/wiki/Perito_Moreno_Glacier

At least 58 New Zealand glaciers advanced between 1983 and 2008, with Franz Josef Glacier (Kā Roimata o Hine Hukatere) advancing nearly continuously during this time. See here:  https://www.victoria.ac.nz/news/2017/02/explaining-new-zealands-unusual-growing-glaciers

Strike 5:

It appears that glaciers in the southern hemisphere are either in a state of equilibrium or advancing…..

How about snowfall? Note this report from a blogger friend about snowfall:

Real Global Snowfall Trend – Zoe’s Insights (phzoe.com)

Strike 6:

Measured from 1980, it appears snowfall has been increasing in the southern hemisphere and decreasing in the northern hemisphere. The global trend is actually up, but this appears to be due to the extra snowfall in the SH…

How is it going with the ice, exactly? I could have shown you the graph I had from Wood for Trees showing an increase in ice surface in the Sh and a decrease in ice surface on the Nh. But it seems Zoe Phin has found another source for the information which could just as well be correct . See here: Global Sea Ice Area – Zoe’s Insights (phzoe.com)

Strike 7:

The large loss in sea ice in the northern hemisphere is more than made up for by a larger gain in sea ice in the southern hemisphere.

With so many strikes against, surely AGW is out and it is now game over! 

Clearly, the heat that warms the earth is coming from the north and is slowly spreading south. Since the extra carbon dioxide that came into the atmosphere since the 1970’s is uniformly spread across the globe, the observed temperature trends indicate that global warming due to carbon dioxide was not the dominant factor over the last 50 years. It appears that the warming observed in the northern hemisphere is dominated by other factors. These factors need to be identified and resolved before any kind of accurate future climate predictions can be made.

In my honest opinion, predictions made assuming that global warming due to carbon dioxide is dominant, are likely to fail.