Why haven't we found aliens? Global Warming. No, really.

We like to think that science is a cold, logical, precise search for Truth-with-a-capital-T, but the fact is that like any other human endeavor science has fads and fashions. For instance, it can still be career death for a physicist to suggest any explanation but String Theory for unifying gravity and quantum mechanics. At the moment, the "fad" in science is Climate Change a.k.a. Global Warming a.k.a. Sustainability. The idea that we have proven no human action is environment-neutral and that survival requires limiting human population growth and activity.

Now, SETI scientists have tried to explain our inability to detect alien life on this same principle. Essentially, the argument goes that any advanced civilization determines that their resources are limited, and thus becomes self-limiting before achieving colonies on other worlds. Thus, no aliens in our neck of the woods.

An interesting idea, but one that is bound to be "disproven" as soon as the winds of scientific fashion shift.