The virtue of a lunar Noah's Ark is that the goal is to save life on Earth.
It's detached from direct commercial interests and other conflicts of interest.
Plus, it's a good facility for everyone in the world to think about.
Given the pressure of time, the advance of technology,
and our shifting perception of ourselves,
what will this Noah's Ark will look like?

Noah's Ark On The Moon
Within the next few hundreds of years, a large asteroid could collide with our planet.
Although there is no evidence that an asteroid is currently on a collision course with Earth, craters on Earth and the moon indicate that asteroid strikes have occurred often over the lifetime of the solar system. The damage to the Earth's environment from a large impact can be catastrophic, with fatal consequences for life. It is widely believed that the dinosaurs went extinct because of such an impact event 65 million years ago.

We also face the possibility of manmade catastrophes. A nuclear conflict could end life as we know it and destroy a large part of the biosphere. Global warming, whether it occurs through manmade pollution or because of some natural climate cycle, also could result in the extinction of many species.