>>11222587Define "cost" OP. Because it's a lot more than money and labor that prevents deserts from being arable land.
First, you need ground that crops can grow in, that means fertile soil. Most deserts are sand or rocks or barren ice.
Second, you need water. That's readily available in the polar regions, what with it being locked up as ice, but those places have other larger problems. Which leads us to:
Third, you need a climate amenable to crops. Most deserts experience ridiculously large temperature ranges over the course of a day; the sort of thing that will kill most crops. Not to mention low humidity, high winds, withering sun, and other environmental hazards I'm sure I'm missing out on listing. There are reasons only the hardiest of plants can survive in those places.
Basically it's logistically impossible. You don't have the dirt. You don't have the water. You don't have the crops that could survive the climate. And even if you had the technology to make those things happen, that same technology would be better deployed in areas that aren't deserts but are already closer to being arable land. In short, we'd have better and more effective things to do if we could convert deserts in the first place.
