John B: Anything with an oxidative metabolism will exhale CO2. The rise in
human population hasn't been that extreme between 1750-1900. But it went up
very
quickly from 1950 onwards. See the following link:

http://www.prb.org/Content/Navigatio...n_Population/P
opulation_Growth/Population_Growth.htm

Very interesting. Many thanks.

Bill, K5BY