On Feb 11, 9:34*pm, Mark Thorson > wrote:
> sf wrote:
>
> > On Fri, 10 Feb 2012 17:00:32 +0000 (UTC), Doug Freyburger
> > > wrote:
>
> > > Human impact *has* accelerated it - lower degree of certainty but still true.
>
> > The way I understand it, the concern isn't that it happens - the
> > concern is that humans have affected the rate and to what degree
> > they're affecting it.
>
> The carbon input to the atmosphere from human activities
> is about 300 times smaller than the input from wildfires.
>
> http://www.mazepath.com/uncleal/tuned.htm

But the carbon from wildfires is carbon that was recently in the
atmosphere anyway. Burning fossil fuels introduces carbon that had
been sequestered in the ground for millions of years.

--Bryan