When correlating CO2 with temperature trends in various periods of cyclical warming and cooling the last 110 years we find a negative correlation from the late 1800s to 1917 (-0.35), positive from 1917 to 1940 (+0.43), negative during the WWII and post WWII boom from 1940 to around 1975 (-0.40), positive from 1975 to around 2000 (+0.36) and negative in the short period to 2009 (-0.56).