Surprising application of discount rates

The blog over at the Economist has a surprising entry. The basic idea behind this blog entry is that there's a large portion of the liberal left who thinks that it is our moral obligation to save the lives of future generations of people who will be killed by our collective apathy towards the environment. The idea is that the future value of those people's lives is worth protecting.

The surprising part is this: if the left believes that we have this moral obligation, then why do they disagree with the moral obligation to protect a fetus? The author of the article does a much better job of pointing out this discontinuity than I can. I recommend the article.

As for myself, I am opposed to abortion. I think the prima facia case is that the fetus is a proto-human being, and I need proof that it's not a human being before I think that killing it is ok. Absent any proof, stealing another person's right to live is wrong. It doesn't matter if that person is dependant on another for survival.

But the author of that article forces me to question my consistency. I don't know what to think about the global warming. On the one hand, there seems to be a lot of evidence that it's happening and that we play some part in causing it. However, I'm generally skeptical of the claim that we must limit economic growth in order to stop it. The above article forces me to ask myself this: if I'm concerned about the rights of an unborn fetus, shouldn't I also be concerned about the rights of future (as of yet unborn) Bangladeshis? If I think that a financial crisis does not justify the restriction of rights to life imposed in an abortion, shouldn't I also think that a financial crisis shouldn't justify the restrictions of rights to life imposed in global warming?

I have to ponder this a bit. My instinct is to recognize what Arnold Kling says about the issue, "I think that people in Bangladesh... are at least as threatened by economic and political backwardness as they are by coastal flooding." This doesn't fully resolve the issue, though. One could make the same argument of a baby: The life of that baby is threatened by finacial crisis of the mother as it is by abortion. This would justify abortion on demand for the destitute. I find that discomforting, but feel compelled to examine my consistency.