So, if human life expectancy went up doing X, we're guaranteed that it will still go up if we continue to do X? That's the same reasoning that caused so many bu

So, if human life expectancy went up doing X, we're guaranteed that it will still go up if we continue to do X? That's the same reasoning that caused so many bubbles. I'm no tree-hugger, but also from a purely egoistical point of view I worry about the consequences of the very fast changes we're causing to the environment in which humans evolved and to which we are adapted. Nothing guarantees that the changes will lead to an environment that can sustain 6+B human beings, so trying to predict the consequences is a very wise thing to do.