Does CO2 make the Seasons?
posted 21st March 2020
Fig 1 Annual levels of CO2 Mauna Loa 1959 to Mar2020
We are constantly told, "increasing levels of CO2 increases temperature". It is the mainstay of global warming advocacy. But is it true in the real world?
Trying to obtain reliable data is always difficult, because of formatting, when dealing with meteorology and even worse with climate change.
For this exercise using CO2 data from Mauna Loa Observatory, Hawaii. (source: [https://www.esrl.noaa.gov/gmd/ccgg/trends/]. This is the longest time span of CO2 observations. You will observe from the link above CO2 does not have a straight line, it oscillates higher in March and lower in September. These two months have the spring equinox where CO2 levels are higher and the autumn equinox, where CO2 levels are lower.
Temperature data for Mauna Loa observatory is very difficult to analyse due to observations being taken at 1-minute intervals and the format. They have no daily, monthly or annual averages. Due to the amount of time it would take to obtain monthly averages from Maua Loa, Hilo 44 Km from the Observatory was used to obtain daily maximum temperature data. Source:: https://www.timeanddate.com/weather/usa/hilo/historic?month
Temperatures are higher as Mauna Loa is on the side of a volcano and Hilo is near the coast at a much lower level. However, the weather and trends will be similar.
Fig 2 shows a view of CO2 levels Sep 2016 to Sep 2019
The seasonal effect is clearly visible. A closer view shows this more readily.
Figure 2 is a bit unfair, some call it "cherry picking and not scientific" as it starts at a spring equinox - low and ends at an autumn equinox - high. Starting at an autumn equinox high and ending at a spring equinox low (blue line) shows a very different view of the trend. Neither of which are an accurate description of the true trend.
There is a visibly strong relationship between the seasons and CO2, lower levels in spring and higher levels in autumn.
Although It is well understood that the position of the Earth in its orbit and relative position to the sun creates the seasons as seen in figure 3
Fig 3 Orbit and axial tilt of the Earth around the sun
Fig 4 shows maximum temperature, CO2 and sunshine for the 4 years
Whilst CO2 has a visible relationship with the equinoxes it does not cause the seasons. If we now look at temperatures, sunshine and CO2 we have a few questions which needs answering.
From figure 4 we see there is a reasonable relationship between max temperature and sunshine of 0.62, no relationship between max temperature and CO2 (-0.09) and no relationship between CO2 and sunshine (-0.04).
Q1. If CO2 is supposed to increase temperature, why is there no relationship with temperature?
Q2. If CO2 is supposed to increase temperature, why is the correlation between temperature and sunshine 0.62?
Q3. Why do the levels of CO2 reduce seasonally, when there is no relationship between CO2 and sunshine?
Q4. Why are CO2 level at their lowest when temperatures are at their highest, this does not conform with the doctrine of global warming?
Conclusion:
Once again, this evidence shows, there is no correlation between temperature and CO2, carbon dioxide does not increase temperature. Whilst CO2 certainly does not have any effect on the seasons, the seasons do have an effect on carbon dioxide.