Somebody needs to run the real numbers ... what activities cost the most energy ( training to get weights, answering queries using weights, etc ), cost of types of energy in terms of external effects (fossil based energy Vs wind|sunlight) demand, bandwidth use, etc.

It's not inconceivable that there's an answer that meets needs based on only running the most energy consuming operations during daylight and migrating those operations about the globe during sunlight hours while having less demand operations run at night.

There's a real issue that needs addressing surrounding ever increasing global emissions, giving lip service while continuing to increase emission related activity is double think.