When I spoke with Kurzweil last week, I asked him about this, specifically how climate change and the environment fits into his theory. (You can hear the whole interview at thelink here.) He responded that stopping climate change matters because many millions of people will suffer if we don’t. He continued:
I have a whole thesis on resources. … it’s really only these exponentially growing information technologies that have a scale to address problems like energy and the environment. … right now solar energy is actually a half of a percent of the world’s energy but it’s doubling every two years and has been for 20 years, so it’s only eight doublings away … which is 16 years, from meeting 100 percent of the world’s energy needs. … do we have enough sunlight to do that? Yes, we have 10,000 times more than we need.