<I>The earth is where we have to make our stand</i>
Why? We have a whole solar system right on on our front porch.
<I>but the total possible water supply we can access (and this includes the glaciers)</I>
Water doesn't just get used once and then disappear forever. Now, one could certainly make an argument against (say) sucking water out of the Oglalla Aquifer faster than it gets replenished, but that's a localized problem. We aren't going to "run out of water". Really.
Why? We have a whole solar system right on on our front porch.
<I>but the total possible water supply we can access (and this includes the glaciers)</I>
Water doesn't just get used once and then disappear forever. Now, one could certainly make an argument against (say) sucking water out of the Oglalla Aquifer faster than it gets replenished, but that's a localized problem. We aren't going to "run out of water". Really.