Dr. Imago,
You ask too much. This experiment could very well cost several thousands of dollars, possibly as much as $5000, and the manpower required would be difficult to obtain. Considering the limited budget that global warming research has had over the past 20 years, a complicated experiment you propose may break the bank. This is the same problem the Hockey Team has in updating their proxies after 1980. Besides, the climate models have all verified the CO2 hypothesis so there is no need for experimentation. Please, can't we move on beyond the science?
See, Svensmark conducting an experiment to test his hypothesis on cosmic rays is irrelevant, but a 112 year old untested hypothesis based on 147 year old data is.
CO2 measurements made prior to 1958 are unreliable due to "outdated" instrumentation and methods, but somehow 1861 technology was well suited for 2007 science.