Well, you could cheat.

There's so much cheap GPU compute used for mining shitcoins and training glorified Markov chains on Reddit dumps, surely someone could spare a few racks to run some CFD on a detailed GIS model of our planet, to create lookup tables that would allow everyone to cheaply simulate all kinds of fun events, such as nuclear detonations, asteroid impacts, "rods of god", relativistic kill vehicles, supervolcano eruptions, etc. anywhere on the planet, at the push of a button.

The social value of this would be immense - even if you and me never used those precomputed LUTs for anything, they would surely help Randall Munroe or Kurzgesagt or others answer even more high-energy "what-if" questions with even greater accuracy!