MIT professor shifts position on geoengineering

[John Nissen]

http://www.technologyreview.com/Video/?vid=502

This is a cautious position statement, from Professor Ronald Prinn at
MIT, who had previously dismissed geoengineering. He says we should
wait before geoengineering because:

(1) We do not yet know what temperature we might have by the end of the
century (various scales are shown in the video).
[JN: Yet we do know that even the current temperature represent
dangerous warming for some countries experiencing drought, and some
low-lying countries experiencing sea-level rise. Can we afford to wait
for certainty as to how high the temperature might be, before we act?]

(2) We do not know enough about the Earth system to have any idea
whether geoengineering would work.
[JN: Yet we have a good idea from basing geoengineering on natural
processes which can be studied and modelled.]

(3) Reducing emissions is considered the best option, and geoengineering
a "last resort".
[JN: Yet emissions reductions alone cannot prevent tipping points being
reached in Arctic and elsewhere.]

Nevertheless, it represents a slight shift in opinion of an important
figure in scientific circles. Is anybody able to contact Professor
Prinn, to discuss his position in this, our geoengineering forum?

Cheers,

John