On 16 May, 20:29, "Michael Tobis" <[EMAIL PROTECTED]> wrote:
> Sure. I agree with that summary but don't see how to turn it into a number.
>
> I believe that the climate risks are already large enough that we
> should choose the lowest target which makes the economic risk of
> disaster small. I think this should be roughly expressed in terms of
> peak CO2 concentration in practice, and that would appear to be in the
> neighborhood of 500 ppmv, assuming the carbion cycle feedbacks don't
> decide to bite with a vengeance.
>
> I don't put much stock in the 2 C number except to say it is the best
> estimate of the outcome of the lowest peak we can achieve, barring
> some unforeseeable technological fix.
>
> mt
>
> On 5/16/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>
>
>
> > > How should we narrow it down in the absence of perfect information?
>
> > Surely the amount of cost/inconvenience/lifestyle change etc..
> > involved has some bearing on whether we consider 0.1C the right target
> > or 6C. If all that was required was for the one big evil oil company
> > to get a patent on GHG free oil, and then that was the end of the
> > story and people could get on with their lives, I'd guess 0.1C and a
> > near immediate and complete ban on GHG's would have been agreed on 20
> > years ago without Hansen having to even bother showing up at that
> > congressional hearing in 1988.
What you are effectively saying, then , Michael, is that, as we almost
certainly can't do any better than keeping GW down to 2C (from pre-
ind?), we may as well take this as a baseline target. Like wise the
the concentration, though between 450-500 ppm is probably achievable,
given the will. Sadly, the current fashion is for 550 ppm; 2x CO2, o
it looks like we are, via our representatives, currently aiming for a
3C rise.
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
Global Change ("globalchange") newsgroup. Global Change is a public, moderated
venue for discussion of science, technology, economics and policy dimensions of
global environmental change.
Posts will be admitted to the list if and only if any moderator finds the
submission to be constructive and/or interesting, on topic, and not
gratuitously rude.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/globalchange
-~----------~----~----~----~------~----~------~--~---
