[ExI] Phil Jones acknowledging that climate science isn'tsettled

[Rafal Smigrodzki]

Spike wrote:

>
>        - First, do they get the notion of negative feedback system
> stabilization in nature?  Nature has a bunch of feedback mechanisms that are
> not at all obvious, even to those studying the systems.  Negative feedback
> loops are everywhere in nature.  The skies would be safer if aircraft had as
> many.
>        - Secondly, do they recognize that we have a long history which
> indicates that huge changes in climate haven't happened in the past?

### Exactly, spike - if climate was unstable in the warming direction
due to the presence of positive feedback effects, then significant
episodes of warming above current levels would have happened already,
simply because of random drift being amplified by the feedbacks - this
is the general property of metastable systems with significant
positive feedbacks and tipping points, they go on exploring their
configuration space. Since such warming did not occur for tens of
millions of years, this essentially precludes the existence of strong
positive feedbacks capable of warming the planet. We know very well
that in the absence of positive feedback CO2 levels would be unable to
cause any harmful warming, therefore we also know that CO2 can at most
cause slight increases in temperature, which along with its dramatic
fertilizing effect on plants would be mildly beneficial for humans.

Rafal