Heart disease and car crashes don't have the ability to derail significant economies in short shrift. There's pretty obviously a huge difference between singular, concentrated disasters and amortized "normal" human death.
I think that as long as we're talking about sub-extinction levels, I disagree with you.
WP estimates roughly one million car accident deaths per year (worldwide est for 2007). Heart disease numbers are more like 30M/year, although lots of those people were very old, so it's hard to estimate what's preventable. Compare that with a hypothetical meteor that kills one hundred million people, in a confined geographic area (that's 1/7 of Europe, or 1/5 of N America, or just half a dozen large Asia cities). What're the odds of that meteor? Even the once-per-millenium Tunguska event wasn't large enough to do that much damage. But suppose once-per-millenium meteors WERE deadly enough to kill 100M people, that's still 1/10 the deaths per year. If it's more spending-efficient to prevent the deaths from heart disease, do that. If it's more spending-efficient to prevent the deaths from meteor impact, do that.
On the other hand, extinction events are worth treating with extra care. Which in fact is exactly what meteor watches do, which is why they only look for entry diameters over 100m. Seems reasonable! Extinction events have happened 5 times in the last 540 million years. They're pretty rare. Maybe we should just roll the dice.
Off-topic: That's not what "shrift" means. Maybe you'd like "short order" or just the clearly "in a short time".
To be clear, I'm not actually saying that a meteor defense system is a reasonable idea. I don't know enough about the topic to say anything interesting.
My point was rather that you can't compare a catastrophe with disease / accidents simply in deaths-over-time. Catastrophes have dramatic economic consequences as well.
Okay, fair enough. I like the "I don't know enough to speak" attitude, and I don't know enough either. (What do you mean, five minutes on Wikipedia doesn't make me an expert?!?! :P )
My reply to your core point is that you can so compare (not least because deaths-over-time have dramatic economic consequences too). Maybe we're just gonna disagree about this one. :)
I believe that from a bang-for-the-buck perspective, Near-Earth Object monitoring is one of the better values. In the scheme of national budgets, it is CHEEEEEP to deploy a ground-based observatory capable of detecting threatening objects. To wit: http://www.planetary.org/explore/projects/neo-grants/2012da1...
If we have the observatories in place, we should have enough time to come up with a reasonable defense.
I believe if we're wiped out by one of these rocks, it'll be due to our own negligence.
Unless we knew about it literally decades in advance, there is little mankind could do (with today's technology) to stop a miles-wide inbound asteroid from hitting the earth.
Though there is a tradeoff in resources vs. other human concerns, I think the math is a bit more complicated. We're not only trying to guard individual human lives but the health of civilization. Just the knowledge that a major asteroid impact was imminent, with no way to address it in time, would be severely destabilizing to global society.
