Does 12000 windmills sound like a lot? Consider that we have 1.7 million oil wells in the USA alone.
How many extra windmills for desalination and freezing to produce snow? How many acres or square miles of desalination plant? How to dispose of the few(!) tonnes of salt? How much of the world's shipping, construction and engineering requires commandeering, WW2 style to ensure it's a ten year not fifty year project?