That is interesting, and I’m not sure I have enough knowledge to really explain that. From a statistical perspective, I would caution you on the “warming was similar” statement: based on the second graph you provided, the trend line increases by about 0.3 degrees Celsius from 1880-1940 (0.005 degrees per year) and by about 1.0 degree Celsius from 1970-2015 (0.022 degrees per year). So the rate of warming was more than 4 times as fast during the latter period compared to the former. I’m not sure I would describe that as “similar.”