2. In general, I think this is well done. I have hopes it will be influential. My question is how the dialog went within your fellow co-authors (any others knowledgeable on Geoengineering?) on Geoengineering. More specifically can you say anything on the differences discussed between CDR and SRM? The first Geoengineering sentence below would seem to suggest that Biochar (clearly a CDR technique) should not be considered a "Mitigation" measure (which I consider it to be)
3. The description of Geoengineering for your C45 panel (re message sent just before this one) clearly states that Geoengineering has two distinct parts (CDR and SRM) - but this below seems to be directed only at SRM. Can you explain why this discrepancy?
4. A new paper was released yesterday by Jim Hansen of relevance. He has (for the first time?) a goal for new additional standing biomass of 100 gigatons carbon (about a 20% increase?). This proposed activity (which I believe qualifies also as both CDR and mitigation) will be a great base for Biochar. Biochar can even accelerate that new 100 GtC through utilizing this substantial new addition to today's land-based NPP of about 60 GtC/yr.. See http://www.columbia.edu/~jeh1/mailings/2011/20110505_CaseForYoungPeople.pdf
(The Vatican Geoengineering material on pp 14-15 is sufficiently short that I include it all here)
Geoengineering: Further Research and International Assessment Are Required
Geoengineering is no substitute for climate change mitigation. There are many questions that need to be answered about potential irreversibilities, and of the disparities in regional impacts, for example, before geoengineering could be responsibly considered. There has not been a dedicated international assessment of geoengineering. Geoengineering needs a broadly representative, multi-stakeholder assessment performed with the highest standards, based for example on the IPCC model. The foundation for such an assessment has to be much broader with deeper scientific study than there has been a chance to carry out thus far.
It may be prudent to consider geo-engineering if irreversible and catastrophic climate impacts cannot be managed with mitigation and adaptation. A governance system for balancing the risks and benefits of geoengineering, and a transparent, broadly consultative consensus decision-making process to determine what risks are acceptable must be developed before any action can be taken.