David, I have given you that 1/2 the heating since 1945 is CO2.
Oh I see what you’re up to. You picked 1945 because it’s tied for being the second-hottest year in that time period, tied with 1943. You couldn’t pick the hottest year, 1944, because anyone reading that might get suspicious that you picked a year that was not a multiple of 5.
Edit: Granted, if you look at this graph there is well over 0.5C of warming between 1945 and 2010, but perhaps another data set such as NOAA or UK Hadley Center might show the 0.4C you’re looking for. However, in this data set, if you pick the date range 1945–2015 rather than 1945-2010, the difference rises to 0.75C (0.87–0.12).
If you pick 1930, 1935, 1950, 1955, or even 1940 as your start date instead of 1945, then suddenly there has been more than 0.6C of warming, even ending in 2010. But if we pick 1950 to 2015, we see that the earth has warmed 1.05C in 65 years —0.16C per decade for 6.5 decades!