Tunguska explosion happened just 100 years ago and had negligible global consequences. If something comparable occurred today above wheatfields of american midwest we’d have mass global starvation and total disruption of the world economy, followed by resource wars, maybe even nuclear ones. And that is not counting the global climate disruption which would again have much bigger impact on food production since today’s varieties are extremely specialized and much less sturdy than those just a century ago.

And please do consider this report from tunguska event:
“On the other side of the planet a sea going freighter equipped with the new amplified radio from Marconi is transmitting position information. The radio operator suffers minor burns as the antenna wires nearly explode in flames. The radio indicator lights go dim, and then out. The expensive triode tube looks as if the glass has melted around the insides.”
(I believe this is the first historical description of EMP burst’s effect on electronic equipment)

So, we don’t need a once-a-100-million-year dinosaur-killer to make a real stink in our global village. A once-a-century firecracker would be quite sufficient.

One thing you left out is that there are additional scientific benefits from developing the technology to safely divert incoming asteroids and comets, and additional societal and civilizational benefits to diverting people’s ready supply of paranoia and fear of the unknown to real existential threats, and away from gay marriage, immigrants and those lame Al-Qaeda guys.

‘Cause those things hardly kill anybody, and overreacting to them doesn’t get us any moon-based laser cannons or asteroid mining equipment :)

Politically speaking, you can only even talk about a shift of priorities like that when the general public are thinking about it (or at least, when the news media are talking about it.)

I feel like I’ve been running a psychological experiment on how people misunderstand and overrate certain low risk events.

People are trying to explain to you that existential threats don’t yield to the same risk calculus as more conventional threats and you seem to be doing everything in your power not to understand this relatively simple point.  You’re not the smartest person in the world.  Try to keep an open mind, you may learn something.

You could also try reading The Black Swan. Does the frequency of impact events obey the Poisson distribution? If not your confidence in your probability calculations might not be justified.

Because with meteors and terrorism the enemy is them, whereas with climate change the enemy is us.

WayLenYaTony … wait no … doesn’t … mmm … Weyland … something *tsk* … Yukon?  Weyland Yukon?  Nah … c’mon, throw me a bone!

An asteroid defense program will put more people into space. There will be more images of the Earth as a on the internet. Astronauts building the interceptors will be advocates for seeing the Earth as a whole system worthy of preservation.

I feel like I’ve been running a psychological experiment on how people misunderstand and overrate certain low risk events. I’d recommend anyone that doesn’t understand what I’m saying to reference this essay.

“Over a several hundred million year time scale the probability is high.”

It’s a fool’s game to evaluate the probability over only short timeframes when making the decision about whether to put funding into detection and defense.  Yes, on short timescales, the risk is low.  But we’re talking about a risk that will last as long as the species does, not a short-term risk.

Given the potential costs, it’s not as useless an investment as you’re trying to say it is.

Again, the key term is “cost vs benefit.” Or if you prefer, “diminishing marginal returns.” 

The main with focusing on smoking cessation, preventable healthcare, and public safety measures is not only that it is expensive, but it involves the messy issues of “free will.” Education (PSAs) and legal wrangling (outlawing super-size sodas, for example) can only get you so far before people start pushing back and things get even more expensive than “naive” calculations.

Asteroids have no free will, so as long as you can avoid miscalculations and resistance that come with any public spending project, the benefits will at least be predictable.

By your reasoning, since the risk is really low, there would be no reason to *ever* build defenses against the event.

Based on the risk as we know it now, there is no reason to build defenses.

And that’s great, up until we hit the “jackpot”.

Indeed. That is how probability works. There is a probability that a civilization-ending meteor could enter the atmosphere directly above the Statue of Liberty on Independence Day. The point isn’t that a probability exists. That is talking in absolutes. What matters is the magnitude of the probability.

That’s great, as long as you completely ignore the potential cost of the event happening, and only look at the short-term probability of the event happening.

No. The risk has been evaluated for all time scales. Over a 100 year time scale the probability is extremely low. Over a several hundred million year time scale the probability is high. If we plan to occupy this planet for several hundred million years, we should build asteroid defenses.

Maybe perceptions could change. Maybe we could fight global warming, maybe people would start caring more about people dying of AIDS or malaria in other countries.

Sure, climate change is a  more pressing problem. I live in a subtropical area that is showing plenty of signs of climate change. All the birds are different now, bananas fruit inland, loquats are ripening right now instead of in April. Galveston is about to build a new system of dikes, but they are just delaying the inevitable if we can’t slow down sea level rise.

I really think committing to asteroid defense would change the way people think and would help us face other global-scale problems. I am totally ready for the war on terror to become a war on asteroids.

That’s great, as long as you completely ignore the potential cost of the event happening, and only look at the short-term probability of the event happening.

If you’re playing russian roulette, one pull of the trigger per minute, the odds don’t look as bad for each minute as they do if you look at that over the space of a few years.