Re: Helium
Yes, helium are something we kind of jettison into space. Our current usage liberate it prematurely from the crust and in a greater rate than it is replenished. So throw it in with my other exceptions. Still, I think a nearby gas giant is a better place to go than invade Earth to take over natural gas reserves (which is where most of our helium comes from I believe).
Biting the hand that feeds IT
