List (cc Ken) 

1. This note is to draw attention to a nice April 2011 comparison of different 
CDR approaches that I had not seen before being sent to it by Chris Vivian.(see 
below). For about 25 minutes of Ken Caldeira comparing most of the CDR 
alternatives at an American Meteorological Society meeting, see 
http://www.youtube.com/watch?v=KbNDG2xFOVg 

2. Quicker is to view only Ken's roughly 25 slides at: 
http://www.ametsoc.org/atmospolicy/climatebriefing/Caldeira.pdf 

3. Here is Ken's final slide, after 1 slide each on most CDR options, broken 
into 3 subgroupings 

Main conclusions 
• Avoiding carbon dioxide emissions is key to reducing climate risk and damage 
• Carbon Dioxide Removal removes cause of climate change and ocean 
acidification 
• There are many approaches to remove carbon dioxide from the atmosphere 
• No approach is obviously both cheap and scalable 
• Best introduce no new kinds of risks 
• May be opportunities for some low-cost mitigation 
• Some could be deployed today or soon 
• Many are understudied 

4. I would have mostly agreed two years ago, and still of course do agree with 
the three main bullets. But now I would modify Ken's last five sub-bullets 
(speaking only for biochar) as follows (and hoping other CDR practitioners will 
similarly append) 

• No approach is obviously both cheap and scalable, but biochar could/might be 
both - because of energy and on-going soil benefits, as well as CDR benefits 
• Best introduce no new kinds of risks, and biochar is in the "best" category - 
no major unavoidable risks have yet been ident ified in any peer-reviewed 
publication 
• May be opportunities for some low-cost mitigation , especially since biochar 
can be coupled with afforestation/refores tation - and costs must be in 
comparison to other options 
• Some could be deployed today or soon, with afforestation and biochar 
especially - as much is happening today even w ithout carbon credits - on every 
continent. 
• Many are understudied, but biochar is rapidly overcoming that hurdle - in 
many countries , through dozens of national and sub-national interest groups, 
and more than 100 University degree programs. 

5. Ken also showed a ranking slide from the Royal Society report - where 
biochar got mostly a "2" out of possible high of "5". I believe most active 
biochar researchers today would give about a "4" on the four ranking 
categories. As near as I can tell, there was no biochar researcher in the 
expert group doing the rankings. I would like to see a new 2013 ranking, with a 
balanced panel. 

6. This is not to say that Ken was in error on anything in his 2011 
presentation. It is just that CDR needs more discussion - especially on 
scenarios with the large (urgency-driven) scales that are becoming more common. 
For new information on biochar costs and market readiness, not available two 
years ago, I hope Ken and others will look at these websites: 
www.coolplanetbiofuels.com and www.biochar-international.org 

Ron 

----- Original Message -----
From: [email protected] 
To: "Chris Vivian" <[email protected]> 
Cc: [email protected] 
Sent: Monday, February 18, 2013 1:27:24 PM 
Subject: Re: [geo] Brief Summary Marine Geoengineering Techniques 



Chris and list: 

<snip> 

5. Most interesting to me was the first half of the same AGU lecture - a talk 
by Ken Caldera comparing several CDR approaches. This is the topic of my next 
note - as Ken's talk had relatively little to do with oceans - and I have seen 
so few CDR comparisons. 


-- 
You received this message because you are subscribed to the Google Groups 
"geoengineering" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/geoengineering?hl=en.
For more options, visit https://groups.google.com/groups/opt_out.


Reply via email to