Correlation between CO2 and temperature

After watching this video for the second time, I got an even more critical view on it. The way they are explaining their arguments seems a bit like a propaganda movie, especially in the end, where they criticising renewable energy sources like solar energy. It could be a propaganda movie for the oil industry. But notwithstanding they made some arguments, which I am going to prove. I will focus on, at my opinion, the main three of them.

·      They were saying that the correlation between CO2 rise and temperature rise are not that high. In particular at time after the Second World War. A time of economic boom with an immense increase of CO2. But at this time the climate was getting cooler. In addition, they pointed out that a rising temperature leads to an increased CO2 level. So they argued the opposite, not the temperature rises because of CO2, CO2 rises because of the temperature.

·      Another argument was, if there is a climate warming through CO2, it should be getting more warmer high in the end of the troposphere than the ground air temperature. According to them, the ground temperature rises more than the troposphere temperature.

·      The last argument was the sun. The sun always dominates our climate. So if something changes with the sun, our climate will change too. They observed the appearance of sunspots and connected them to the climate warming, it was a quite good correlation, even better than the CO2.

According to the statistics of the 5^th IPCC report from 2014, there is indeed no correlation between CO2 and temperature in the time 1950 – 1975. In particular the correlation between the anthropogenic CO2 and the temperature seems not to exist. 

Figure 1:  5^th IPCC report 2014

If you take a closer look just at the temperature, I found some graph in the 1^st IPCC report from 1990, you will see that our climate increased the temperature in two periods, from 1910 to 1940 and from 1940 to 1975. Between these two periods, were especially on the north hemisphere a cooler climate period. In the IPCC report is not real explanation for that, they are just speaking about some periodic changes in climate. But the main problem is, where is the connection to CO2? (1^st IPCC report 1990)

Figure 2:  1^st IPCC report 1990

I don’t like to admit it, but it seems the propaganda video at least made one good point. So far for today, soon I will be back with hopefully an explanation for the cooling period.