According to fraudulent GISS temperatures, Earth warmed 0.5C from 1910 to 1940, when CO2 rose 10 PPM. Since then, temperatures rose another 0.5C, with an increase of 80 PPM
So we can calculate 1910-1940 CO2 sensitivity as 0.5C/10 PPM = 0.05C/PPM
Post 1940 sensitivity is 0.5C/80 PPM = 0.00625C/PPM
In other words, their imaginary “CO2 sensitivity” has dropped by a factor of eight since 1940.