On Jan 28, 1:07�pm, Stewart Robert Hinsley
wrote:
In message , Ron Button
writes

I don't have the literature to hand, but supposedly carbon isotope
ratios demonstrate the anthropogenic source of the additional
atmospheric carbon dioxide.
--
Stewart Robert Hinsley

As far as I am aware - source Hadley Centre - it has not been possible
to measure the isotopic signal of anthropgenic CO2
since 1945 due to atomic bomb contamination of the atmospheric.

Dick Lovett
Charlbury