Sunday, July 20, 2008

Run Away!

clipped from www.coyoteblog.com


Yet it is reliably inferred from palaeoclimatological data that no “runaway
greenhouse effect” has occurred in the half billion years since the Cambrian
era, when atmospheric CO2 concentration peaked at almost 20 times
today’s value


Positive feedback can be weird and unstable.  If there is enough
of it, processes tend to run away (e.g. nuclear fission),

Most scientists, when then meet a new process, would probably assume negative
feedback until proven otherwise.  This is a particular issue in climate,
where folks like Michael Mann have gone out of their way to argue that the world
temperature history over the last 1000 years before man began burning fossil
fuels is incredibly stable and unchanging.  If so, how can this be
consistent with strong positive feedback?