[extropy-chat] global warming eats island

[Keith Henson]

At 04:36 PM 12/31/2006 -0600, Damien wrote:
>At 03:06 PM 12/31/2006 -0500, Keith wrote:
>
> >Given that we want to keep the earth
> >close to the current temperature or even cool it a bit, what method is the
> >least disruptive?  It might turn out that a mess of sunshades in the
> >earth-sun L1 location are the best (least clostly) way to go.
>
>Two features are being conflated, and I don't know how much expert
>work has been done on this (other than knowing that yes, stabilized
>solarettes could be put there). My wife the hands-on and
>theoretically-informed practical permaculture farmer is aghast at the
>handwaving involved. You cool the planet by deleting some significant
>proportion of current insolation (using shades or aerosols or
>whatever), and what happens to the crops and grasses and livestock
>that have evolved or been bred to roughly our recent annual round?
>This is a vast multidimensional question.

Plants can't use all the sunlight that comes down on them, they saturate 
with light.  CO2 is more of a limiting factor.  And IIRC, the amount you 
would have to cut to dump the earth into an ice age is only a few 
percent.  I don't think any sunshade proposal has talked about more than a 
.5 to 1% cut.

Keith