Guest post by Willis Eschenbach (@WEschenbach on eX-Twitter)
Common Fonts for Error Messages The Guardian has an article claiming the following:
2023 is the hottest year on record, and preliminary findings from an international team of researchers show a temporary decline in the amount of carbon absorbed by land. The end result is that forests, plants and soils – as a net category – sequester almost no carbon.
Well, when my bad number detector started going off…it sounded fishy. About 55% of emitted carbon dioxide is stored and 45% remains in the air. Of these, approximately 75% are isolated on land. Therefore, if land sequestration “collapses,” we should see an immediate jump in air CO2 levels of about 75% * 55% ≈ 41%. But I don't remember seeing that in the data…hmm.
In fact, the surge in carbon dioxide levels in the atmosphere is exactly what the “preliminary findings” paper linked above use as the basis for their claims about carbon sinks, namely (emphasis mine):
In 2023, the carbon dioxide growth rate will be 3.37±0.11 Mauna Loa's carbon dioxide emissions increased by 86% from the previous year, reaching a new high since observations began in 1958, while global fossil fuel carbon dioxide emissions increased by only 0.6 ± 0.5%. This means that land and ocean sinks have weakened as never beforeand raises the question of where and why this reduction occurs.
…
The average carbon dioxide growth rate during the ten-year period from 2013 to 2022 is 2.42 ± 0.08 ppm yr -1 . In 2023, it increased to a record high value 3.37 ± 0.11 ppm year-1 Mauna Loa Station (MLO).
Wow, biggest jump on record,”means an unprecedented weakening of land and ocean sinks“! Everyone is panicking!
As is my custom, I went to the Mauna Loa site and obtained CO2 data. Since the data is monthly, I converted it to annual data. Here is the result, showing the growth rate for a given year as the average of the previous year minus the average for the given year.
Figure 1. Annual changes in atmospheric CO2
Well sez I again… the change from 2022 to 2023 looks perfectly average and is 2.5 ppmv which is certainly not the 3.37 ppmv they claim. Why is this happening? They cannot calculate the difference in annual averages.
Take a closer look at the NOAA folks calculating what they call ” “Average annual growth rate” The mystery is explained.
CO’s average annual growth rate2 The concentration difference in a given year is the concentration difference between late December and early January of that year. If used as a global average, it would represent the sum of all carbon dioxide2 Added to or removed from the atmosphere throughout the year through human activities and natural processes.
There is a small amount of variation in CO from month to month2 Concentrations that may be caused by wind or weather system anomalies reaching Mauna Loa. This change is not representative of the basic trends in the northern hemisphere represented by Mauna Loa.
Therefore, in March we finalized our estimate of the average annual growth rate for the previous year, using The average from the most recent November to Februarycorrected according to the average seasonal cycle, as the trend value on January 1. And obtained.
Now, this all sounds perfectly legal, but it doesn't explain the huge value in 2023. So I looked at the data for each month. Figure 2 below shows them averaging the most recent data for the four-month period from November to February.
Figure 2. Year-to-year differences, monthly carbon dioxide data. The blue bar highlights the period from November to February used in the calculations
Following their instructions, I could accurately replicate their calculations. In Figure 2 we can see why they get such high numbers – the data centered on January 1, 2024 occurs during the peak annual CO2 rise, while the data centered on January 1, 2023 Happens at low tide.
What's the difference? Well, they calculated a four-month average starting in November and compared it to the same period last year…but they could just as easily calculated a four-month average starting in January or June and did The same calculations are made for year-to-year changes.
But here's the thing. If they had a chance to start the four-month average in January instead of November, the difference from 2022 to 2023 wouldn't be the largest jump on record, This is only the 24th in 64 years. If they start in February 11th largest. If they start in June, that's seventh largest Jump into the record.
Of course, this means They claim carbon sinks “Failing” It is a completely forged product of their calculation methods.. It all depends on the random choice of month they use to start the four-month average, and if they start in January they would be forced to conclude that nothing unusual is happening with the carbon sink.
Falling into confirmation bias on more than one occasion, I can only sympathize with the author. They were looking for a climate catastrophe that they thought they had found, but unfortunately because it confirmed their preconceptions, they didn't dig deeper.
And yet… they're still completely wrong. The data did not show any changes in carbon sinks. This is just an artifact of the weird way they calculate “annual” changes.
Best wishes to everyone, I'm going out to see the moon.
w.
as usual: When you leave a comment, I ask that you Quote the exact words you are discussing … This will avoid endless misunderstandings.
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