SEED, home t0 many disreputable scoundrels, has a piece up with different perspectives on geo-engineering. I haven’t read through all of them (I was mainly interested in what Caldeira had to say), but plan to over the weekend.
Additionally, I admit that I am more than a little critical of Roger Pielke Jr. on this blog, so I thought it worth pointing out that I thought his take was sensible and clearly articulated. It would be easy to spin parts of his comments to champion my own take on the issue or ignore them altogether, but that’s not the way intellectually honest people comport themselves. So, kudos to Roger.