Mauna Loa Observatory, Hawaii
Fig 5 shows monthly mean CO2 at Mauna Loa, Hawaii
If CO2 increases temperature how does it fall from spring to "fall"? It is obviously seasonal, but CO2 does not make the seasons, that is most definitely the Earth's position in relation to the Sun.
From a History of Mauna Loa Observatory:
"Even just months into the program, the monitoring at Mauna Loa was already producing revolutionary results. In November, when Charles Keeling first made the winding trek up the volcano, the measurements showed the concentration of carbon dioxide increasing—slowly, but steadily. Then, in the summer months, the opposite happened, with carbon dioxide concentrations dropping. The pattern repeated itself, almost exactly, during the second year of measurements. Keeling was fascinated."
"We were witnessing for the first time," he wrote in his autobiography, "nature's withdrawing CO2 from the air for plant growth during the summer and returning it each succeeding winter." They had, in essence, captured a picture of the northern hemisphere drawing and releasing breath—exhaling carbon dioxide as forests turned bare for the winter, and inhaling as the leaves returned each summer.
These statements show CO2 is not a well-mixed gas in the atmosphere, it lower in summer and increases in winter at Mauna Loa (Northern Hemisphere). Temperature is higher in summer and lower in winter at Mauna Loa (Northern Hemisphere). Therefore, with higher temperature, CO2 is lower or with lower CO2, temperature is higher, which is contrary to the IPCC hypothesis that CO2 increases temperature. Keeling was observing a perfectly normal natural phenomena.
After reading this I investigated the relationships between mean monthly: sunshine, temperature, our Photosynthesis Index, and carbon dioxide at Mauna Loa.
Fig 6 levels of CO2, photosynthesis Index, sunshine hours, temperature & CO2 Mauna Loa, Hawaii
The most notable aspect of this analysis was the correlations between each measurement.
Photosynthesis Index (PI) vs Carbon dioxide (CO2) 0.078
PI vs Temperature (T) 0.972
PI vs Sunshine (S) 0.978
T vs S 0.905
T vs CO2 0.001
The relationship between temperature T and CO2 is statistically insignificant, which means it is almost impossible for carbon dioxide to increase temperature.