This raised the question for me of how long could we sustain this before the loss of mass to the moon started to affect earth? 22 billion tons a year seems massive but doing that for 100 years would only decrease the moon's mass by 2.2e-11 which seems completely insignificant (not that I would know what is insignificant here) and if we had not solved the problem in 100 years we probably have bigger issues anyways. How long could such a thing be maintained before we had to start thinking about the new problem that we were creating? Working at the astronomical scale has never been a strong point for me.