The steadily increasing global carbon dioxide concentration is further recognized through the decreasing trend of 13C/12C isotopic ratio in the annual rings of twentieth-century trees. The decrease is averaged to about 0.012 per mil per year which is attributed not only as due to anthropogenic fossil-fuel burning but also to the man’s impact on the land pattern.
No takes yet. Share an insight, caveat, or question.
Morley Pandula de Silva (1979) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: