Contra Jonah Goldberg, Matt Yglesias argues that the possibility of an asteroid strike has no bearing our concern about global warming.

Personally, I’m sympathetic to the view that public policy should be more concerned than it currently is about asteroid strikes. But this is also a total non-sequitur. Failing to pass the Waxman-Markey bill or negotiate a good deal at Copenhagen doesn’t put us any closer to safeguarding ourselves against asteroids. Nor would enhanced monitoring of potential collisions require us to build new coal-fired power points. The two issues simply have nothing to do with each other.

This is not quite right. Whether asteroids or other existential threats should have a major impact on how we deal with global warming is debatable, but they are definitely related for two reasons.

First, and I in no way want to condone the style or tone of Jonah’s presentation, but there is a logical strain behind it. The underlying assumption is that the public and the scientific community have limited attention for existential threats and that too much of this attention is directed to climate change.

There are other bad things that could happen: asteroid strikes, pandemics, nuclear terrorism. We shouldn’t expend a disproportionate amount of national attention on any single one. In short, unless you believe the reservoir of public concern is infinite you can’t think that the public should be more concerned about asteroids but that asteroids have no impact on how much we should be concerned about everything else.

Further, the argument might go, we should be weary of over hyping nuclear terrorism because it fits with the basic world-view of the right. There is a natural tendency for nationalism to fuel this fear and so there is a strong chance it will receive too much attention.

Similarly, we should be weary of climate change because it fits the world view of the left. There might also be a tendency to give too much attention to the dangers of industrialization and consumer culture.

Now, I tend to think this argument may be overplayed on both sides. Though, yes there are people concerned about nuclear terrorism and climate change for all the wrong reasons, it is nonetheless the case that they are significantly larger threats than average. Its not so bad that they get a lot of attention.

Second, each additional threat lowers the optimal amount of resources spent on addressing all other threats. In practice the reason people are motivated about terrorism or climate change is because the two concepts are frightening. They are a source of worry and doing something calms worry.

However, from an analytical point of view the reason we should do something about these threats is because we care about the future. However, the greater the probability that the future will be destroyed anyway, the less important action is on any one threat.

That is, if we knew that preventing Iran from developing a nuclear weapon or reducing carbon would mean a prosperous future for our grandchildren then we should invest an enormous amount resources into assuring that it happens.  However, if there is a non-trivial chance that our grandchildren will live in disaster anyway, we should hedge. After all, there is a chance they we could suffer the consequences of action and they still gain no benefits from that action.

Now, I think the chances are pretty large that our grandchildren will in fact in enjoy a prosperous future and thus the effect of additional disasters on our calculus is not that great. However, it is not zero.