Back in 2018 Jo Nova publicised Dr John McLean’s exposé of the many ridiculous flaws in HadCruT4, the global temperature dataset, which included until a year ago the oceanic component, HadSST3. That was bad enough, with some data from positions 100km inland from the nearest sea. But in June 2019 the long awaited HadSST4 was released, in which many corrections were made to reduce “problems” in the sea surface temperature record.
Corrections indeed.
Figure 1 is a comparison of HadSST4 with HadSST3.
Figure 1: HadSST3 and HadSST4 since 1850
And figure 2 shows the extent of the “corrections”.
Figure 2: Adjustments: HadSST4 minus HadSST3
You will no doubt note how the “corrections” have made the past cooler, as is standard practice for all those curating temperature records. Indeed, apart from a small foray in the 1940s, the whole 100 years from 1875 to about 1975 has been made ever so slightly- up to a tenth of a degree- cooler.
But in an interesting move, all temperatures since then have been corrected, and, would you believe, upwards. Who would have thought that the average sea surface temperature measured just a couple of years ago in September 2017 was 0.1875 degrees too cool, and needed revising upwards?
Figure 3: HadSST3 and HadSST4 since 2010
Modern thermometers just aren’t what they used to be.
In my last post I wondered whether the largest real-life science experiment in history will show whether atmospheric carbon dioxide concentrations will decrease as a result of the Covid19-induced economic slowdown.
I concluded: “I expect there may be a small decrease in the rate of CO2 concentration increase, but it won’t be much, and I will be surprised if it turns negative. A large La Nina later this year will lead to a CO2 increase a few months later, in which case there will be a larger downturn in annual CO2 change in 2021.
However, if the major cause of CO2 increase is fossil fuel consumption, there will be an extra large decrease in CO2 change in 2020 and 2021- and a noticeable jump if the global economy rebounds.”
Figure 1 shows the 12 month change in CO2 at Mauna Loa since 2015-that is, January to January, February to February, March to March (as in Figure 6 of my previous post):
Fig. 1:12 month change in CO2 concentration since 2015- Mauna Loa
The CO2 concentration number for April is now published: 416.21 p.p.m. (parts per million). That’s an increase of 1.71 ppm over the March figure, and 2.89 ppm above the figure for April last year. Figure 2 is the April update on Figure 1.
Fig. 2: Updated12 month change in CO2 concentration since 2015- Mauna Loa
Notice the amount of 12 month change has increased, despite at least two months of downturn in China and at least a month in most other countries.
Figure 3 is a monthly update for 2020 I will show as each month’s CO2 figures become available (and 2021 if necessary):
Fig. 3: Updated12 month changes in CO2 concentration for 2020- Mauna Loa
Figure 4 shows the range of 12 month changes for each decade since the record began in 1958:
Fig. 4: Updated12 month changes in CO2 concentration all decades- Mauna Loa
Figure 5 shows the same, but just since 2000:
Fig. 5: Updated12 month changes in CO2 concentration since 2000- Mauna Loa
Note that so far this year, 12 month changes are in the upper range, and there is no sign of any slow down.
Watch for next month’s update, and enjoy the ride!
The Coronavirus pandemic has already caused a huge downturn in many industries world-wide- especially tourism, manufacturing, and transport. Prices of oil and thermal coal have fallen dramatically. The first impact was on China, as this plot from the World Economic Forum shows:
Fig. 1: Industrial production in China
Industrial production has fallen by 13.5% in January and February, and exports have dropped by 17%. While China may be recovering from the virus, the rest of the world is not and knock-on effects from low Chinese production of essential inputs will hold back recovery in other countries.
So the question is: if atmospheric concentrations of carbon dioxide and other greenhouse gases are largely a product of fossil fuel emissions, and if fossil fuel emissions decrease, will we see a reduction in the rate of increase of CO2, and if so, how much?
This is the biggest real life experiment we are ever (I hope) likely to see.
Background:
The concentration of CO2 in the atmosphere is increasing, as in Figure 2.
But what we are vitally interested in, is how much we may expect CO2 concentration to change. We can show change, and remove the seasonal signal, by plotting the 12 month differences, i.e., March 2020 minus March 2019. Thus we can see how much real variation there is even without an economic downturn. And it is huge.
Fig.4: 12 month change in CO2 concentration- Mauna Loa
Fig. 5: 12 month change in CO2 concentration- Cape Grim
Not very much smaller at Cape Grim.
However, the Mauna Loa record is the one commonly referred to. Figure 6 shows the 12 month changes since 2015.
Fig.6: 12 month change in CO2 concentration since 2015- Mauna Loa
We will keenly watch the values for the remaining months of 2020, and then 2021.
My expectation?
I will be very surprised if there is much visible difference from previous years at all, as the following plots show. Figure 7 shows the time series of annual global CO2 emissions and scaled up atmospheric concentration from 1965 to 2018 (the most recent data from the World Bank):
Fig. 7: Carbon Dioxide Emissions and Concentration to 2018
Fig. 8: Carbon Dioxide Emissions as a Function of Energy Consumption to 2018
There is a very close match between emissions and energy consumption of all types- including nuclear, hydro, and renewables.
Fig. 9: CO2 Concentration as a Function of Carbon Dioxide Emissions to 2018
Again, it is close, they are both increasing, but with some interesting little hiccups….
So what is the relationship between change in atmospheric concentration and change in emissions?
Fig. 10: Percentage Change in CO2 Concentration as a Function of Percentage Change in Carbon Dioxide Emissions to 2018
Not very good correlation: 0.01.
Fig. 11: Percentage Change in Energy Use, GDP, and Carbon Dioxide Emissions to 2018
GDP fluctuates much more than energy or emissions, which are very close, and if anything tends to follow them.
Figure 12 is a time series of annual percentage change in energy and emissions and absolute change in CO2 concentration.
Fig. 12: Percentage Change in Energy Use and Carbon Dioxide Emissions and Absolute CO2 Change to 2018
You will note that during the three occasions (1974, 1980-82, and 2008-09) when global emissions growth went negative (as much as minus two percent), CO2 concentration barely moved, and still remained positive, and on two occasions when CO2 concentration increased by 3 ppm or more (1998 and 2016), emissions increase was much reduced.
Ah-ha, but that’s because the volume of the atmosphere is so huge compared with the amount of greenhouse gases being pumped out- according to the Global Warming Enthusiasts.
In Figure 10 I showed that there was little relationship between annual change in CO2 emissions and atmospheric concentration. Figure 13 shows what appears to have a much greater influence on CO2 concentrations: ocean surface temperature.
Fig. 13: Annual Change in CO2 Concentration as a Function of Change in Sea Surface Temperature (lagged 1 year)
Remember the correlation of CO2 with emissions in Figure 10 was 0.01. The correlation between CO2 and lagged SSTs is 0.59. That’s a pretty devastating comparison.
Figure 14 shows how in most years SST change precedes CO2 change throughout the entire CO2 record.
Fig. 14: Annual Change in CO2 Concentration and Sea Surface Temperatures
There is little evidence for CO2 increase causing SST increase, while there is evidence that SST change (or something closely associated with it) leads to CO2 change. The largest changes coincide with large ENSO events.
Conclusion:
Therefore, I expect there may be a small decrease in the rate of CO2 concentration increase, but it won’t be much, and I will be surprised if it turns negative. A large La Nina later this year will lead to a CO2 increase a few months later, in which case there will be a larger downturn in annual CO2 change in 2021.
However, if the major cause of CO2 increase is fossil fuel consumption, there will be an extra large decrease in CO2 change in 2020 and 2021- and a noticeable jump if the global economy rebounds.
As I said, a very large real life experiment. So watch this space!
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