I agree weather controls exist - in fact, they’d probably be needed to solve extreme heat and drought in the city.

However, I don’t think terraforming Mojave is the same thing as terraforming a planet - most planets they colonize that aren’t already suitable for human life don’t have a native ecosystem to begin with. What the pilot seems to depict is the elimination of an existing ecosystem and many habitats, which I feel doesn’t seem very Trek-esque. While they would modify the local environment to improve living conditions, I don’t think they would be inclined to do this much environmental damage.