That's Joe Katzman's comment at this interesting post by Donald Sensing on a major asteroid impact in North America thirteen thousand years ago.

...the worst consequence of the cataclysm was the mass extinctions of the late Pleistocene that have heretofore been attributed to overhunting by the Clovis peoples of the continent. The extinctions were additionally blamed on the Younger Dryas. The new impact theory, though, says that the comet's multiple explosions (caused by its breakup in the high atmosphere) themselves caused the extinctions: "at least 35 genera of the continent's mammals went extinct – including mammoths, mastodons, camels, ground sloths and horses." That's 35 whole genera, not just species, that died out. Just at the time of the extinction the researchers found a significant band of soot in sediments from widely-separated sites.

Let me be the first to blame George Bush.

Evidence continues to accumulate that this sort of thing happens a lot more often that we used to think (particularly considering that thirty years ago few people thought that it ever happened). We're going to feel very stupid if we get hit by one that we could have diverted had we not been so short sighted about becoming spacefaring for the past half century.

Unfortunately, the short sightedness continues, in the form of ESAS. And actually, for that, I do blame George Bush, though I guess he thought that once he hired a rocket scientist to run NASA, he didn't need to think about space any more.