Carbon Dioxide Surge and Ambitious Science

From this weeks Earthweek, there are icebergs floating off of New Zealand. I also saw a post about this from a member of a list I'm on who lives there and was somewhat dismayed. They pointed the bergs out as a direct result of global warming. Also, at least in the newspaper version, a comment that the "rate at which carbon dioxide is entering the atmosphere is increasing four times faster than it was in the 1990's."

Makes it tough to believe that simple things we can do are enough. Mind you, we should still do them.
It may take some ambitious global engineering to help.
I read an article last week about a proposal to put a giant shield over the Earth. In fact, one blog entry on it from the journal Nature mentioned a story Larry Niven and I wrote called "Ice and Mirrors" which suggested a planet was thrown into a deep freeze through a vaguely similar technique. Today, I read an article that talked about putting extra pollution into the atmosphere to shield us from the sun. I don't much like either of these choices - the shield idea is incredibly expensive and the pollution idea just seems wrong (likely some unanticipated consequences there, or just bad trade-offs). But I like it that people are thinking this way. Anything about us doing this kind of grand engineering is scary given the chaotic nature of the climate and the large gaps we still have in our knowledge of it, but we may be doing enough damage that the only solutions are grand.