Although I think man is in no way going to be able to reduce his greenhouse emissions enough to avoid serious global warming (far too many trendlines are tilting far too heavily against that result) and that geoengineering is perhaps the only way to save the Earth, I am glad to hear that Planktos is backing down from their plan to trigger blooms of phytoplankton in the Pacific. They just had not done enough research to know what would happen with their experiment, and had neither the necessary scientific nor the political consensus to proceed.
Politicians need to come to come to grips with this kind of international situation, and fast. Unfortunately, that's...well, unlikely. I mean, here in the US we are barely even catching up with the Internet, law-wise, and fancier technologies are even further. Regulate nanotechnology? Congress barely even knows what it is. International diplomats are content to bask in the glow of the Bali "breakthrough" (as I saw it put in a UN email the other day), while temperatures and GHG levels continue to rise at record rates.