Is it really necessary to send humans to those places just to get the knock-on benefits? Couldn’t we do those things directly, without going there?
It seems to me that, today, those who have the money to spend on these endeavors would only do so if there were perceived short-term benefits to themselves. That means they plan to exploit the resources, or increase their own power somehow.
I know the good engineers that make this happen are doing it for the challenge and in the pursuit of knowledge, and I know that’s why we poors support it, but that doesn’t “pay the bills.” What is the motivation behind the money? Why are they really doing this?
Frankly, there’s no point. We already know how to green the Sahara. That fact is not in any doubt. You don’t actually prove anything or accomplish anything by doing so. We have all the technology; there’s just no economic reason to do so. Spam solar panels, desalination plants, and water pipelines. Technologically, it’s quite simple. Performing such a thing would prove nothing about our ability to settle Mars. The technical challenges are completely different. Whether we can actually settle Mars is a different question entirely. Settling somewhere on Earth does not provide any useful information on whether we can do so on Mars.
And ultimately, the point of expanding off Earth is so we don’t have all our eggs in one basket. You’re just proposing that we more heavily exploit our current basket, rather than expanding out to another one.
And terraforming is hardly the first step here. You don’t jump directly into something like that. You figure out how to build a city first. Once you have a billion people living on Mars, then you can consider something as grand as terraforming.