Here’ is the first report I’ve seen on the conference this past week on geoengineering. I would have like to attend, but didn’t have either time or money right now. I was a little disturbed by what seemed to be an absence:
Participants…split into groups representing the two broad kinds of geoengineering: methods which block solar radiation from the sun, like spreading aerosols in the stratosphere, and techniques to remove carbon from the atmosphere, like growing algae blooms at sea.
…A vexing question for participants was the role of commercial companies in this controversial field. A breakout group devoted to the idea of blocking sunlight—by whitening clouds or the ocean surface, for example—couldn’t agree on whether it should propose barring for-profit companies from the enterprise.
Ignoring the issue of the role of private enterprise, what I’m reading seems very terracentric (which isn’t uncommon among the scientific community — I think it was one of the reasons that it there was so much skepticism about Alverez’ dinosaur-extinction theory). After all, if the goal is to block sunlight, the closer to the source you are, the easier the job might be. Maybe there were some space-based solutions discussed, but you can’t figure it out from this report. One of the reasons that I wanted to attend was to provide a perspective that might not otherwise be there, and it looks like my fears were born out.
I’d bet that if you proposed (say) Ehricke-type solettas, or sunshades, you’d be laughed out of the room, largely out of ignorance of space transportation economics. I would have provided a tutorial to explain why it’s foolish to extrapolate costs of current launch systems to future large-scale space access, because I’ll bet that’s exactly what most of them would do (because it’s what most people do now). I’ll look forward to a more detailed report on the conference, though, including a full list of presentations.
[Monday afternoon update]
It should be noted that I’m not advocating geoengineering. I’m just pointing out that for those who do, they shouldn’t exclude space-based solutions because of false preconceptions. It’s sort of like my attitude toward NASA. I wouldn’t weep much if the agency was defunded (other than the personal impacts on my friends who are employees and contractors). But seeing as how that’s unlikely to happen, I’ll continue to lobby to at least have the funds spent sensibly, in terms of actually advancing us in space.