[jessriedel]

I think the reasoning is that an AI singularity is more likely than not within the next 2 centuries. During that time, people can differ about whether they think nuclear war, nanotech, or bioengineered pandemics are likely. But the risk of a catastrophic asteroid strike are basically known, and small. (1km asteroids hit the earth every 500k years.) So, depending on your assumptions, asteroid deflection might be the most cost-effective existential risk to mitigate, but it shouldn't be the most statistically feared.