[mseebach]

That's not very different. It implies a level of wealth that can't be made available to the poor, regardless of the fact that we have in our selflessness given it up.

The answer to "we can't afford it" is the same to many other scenarios where you can't afford something but need to get it anyway: Figure out how to make it work. Inventing non-fossil liquid fuels would make a very good start.