News.com’s blog reports on how much oil we have left, in the estimate of Chevron CTO Don Paul: About 1 trillion gallons that we can extract, and another trillion that, for now, we can’t. In a hallway conversation with a News.com reporter, Chevron’s Paul estimated that we will have consumed half of all the oil that ever existed — 1.5 trillion gallons, out of 3 trillion — by 2012. From the story:

Thus, peak oil–the theory that we’re about to get into declining numbers on conventional oil–is probably real. However, Paul said, “I don’t think it has to be the catastrophe that other people have predicted, because there are other ways to make fuel.”

Watch TED.com in the coming weeks for more on alternative fuels, including Juan Enriquez‘s recent talk at TED’s fall Salon, on new ways to grow energy — related to his exciting work with Craig Venter at Synthetic Genomics.

Or take the point of view of TEDTalks favorite James Howard Kunstler. Near the end of Kunstler’s talk on modern suburbia, he describes a post-peak-oil future that actually doesn’t sound that bad: We’ll work and eat locally. We’ll rely on our neighbors. We’ll … walk.