"Terry Harper" wrote in message ...
"Alex Terrell" wrote in message
m...

Are you saying:

a. The current CO2 levels are a natural phenomonen. For the last
700,000 years, CO2 concentration has varied between 180 and 300ppm. In
the last 100 years, it has risen from 280 to nearly 400 ppm.

http://www.daviesand.com/Choices/Pre...ning/New_Data/

The graph indicates a number of peaks at about that level, 140,000; 240,000
and 320,000 years ago. Most of the time it has been substantially lower. The
peaks coincide with peaks of temperature.

The red line has always remained below 300 ppm, except on the extreme
right. Other graphs then show how over the last 100 years it has gone
from baout 250 to 370.

or,
b. That increased CO2 levels have no impact on climate, and that
something else causes CO2 levels and temperatures to correlate.

Nobody denies the correlation. Cause and effect are the points which are
debatable.

It is feasible that increasing temperatures cause higher CO2 levels,
though the time lag, and climate models indicates the reverse.