On Mar 6, 12:10 am, Just Wondering wrote:
wrote:

Note that the highest CO2 concentration over the last half
million years is a bit over 300 ppm. The current concentration
is 380 ppm.

IF that is true, it's also true that the earth is far from the hottest
it's been during that same time frame. Which would seem to indicate
that CO2 concentration is not the cause of global temperature levels.

Sure, if you ignore Physics and rely on blind correlation instead.

You seem to under appreciate the distinction between 'the'
and 'a'. Changes in atmospheric composition must be a
cause of changes in global temperature. That is basic
Physics. To claim there can be no other causes is absurd
to the point that it suggests an effort to avoid meaningful
discussion.

Other factors forcing temperatures down, at the same time that
an increase in Greenhouse gases is forcing it up, are well-
established--see Global dimming.

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FF