[palmer]

The atmosphere has such low thermal mass that changes in heating from seasonal CO2 level, should be detectable.

There's no way to show that. For one thing the solar input increase from summer to winter (at perihelion we are closer to the sun) dwarfs the decrease in CO2 forcing. Second, the seasonal change is altered by the large ratio of land in the NH to SH.

Bottom line is there won't any trace of a seasonal CO2 signal in climate. Seasonal analysis is a black hole for climate attribution studies.

[bill1952]

>Bottom line is there won't any trace of a seasonal CO2 signal in climate.
Seasonal analysis is a black hole for climate attribution studies.

Okay, how about decades? 50+ years?

If you extend back to 1958, the co-efficient of correlation between CO2 and HadCRUt global temperatures is 0.907.

How significant is that?

Well put it this way : The co-efficient of correlation between the number of Home Runs hit in MLB and HadCRUt global temperatures over the same time period is 0.885.

Make of that what you will!