If it "would require less than a tenth of processing power" while being "very feasible and does not require significantly more development effort" I think you should get in touch with Google or Facebook with your suggestion.
You can solve two problems at once - you will lower their carbon footprint to 1/10 of their current one, and become a multi-millionaire or even billionaire. Sounds like a double win to me.
That's the problem we're talking about. It is very feasible but only if performance and energy use is something you want to focus on, while accepting the economic penalty of not prioritizing time-to-market. This is just yet another case of unchecked capitalism and free market destroying the planet. Focusing on energy and resource conservation may be more important as well as feasible, but it's not quite as economically competitive. Unless the industry as a whole decide to do what's morally right, or it is regulated and mandated by the government.
You can solve two problems at once - you will lower their carbon footprint to 1/10 of their current one, and become a multi-millionaire or even billionaire. Sounds like a double win to me.