Originally Posted By: mjoekingz28
Are we reproducing minerals (like growing tree....renewable) or are we using the only supply?
Like, as in, we burn a drum of petroleum it may not be replenished soon. But what about metals and ores, fertilizers, chemicals-and other such stuff.
Like my canned goods. Do we just have to keep mining deeper into the Earth to get more (since we have probably taken most of the topsoil/low hanging fruit)?
Thanks
Overall, the total amount of any element -- iron, nickel, tin, carbon, oxygen, nitrogen, etc. -- is constant. What changes is the form that element is in.
As we mine more tin and make more cans, that tin hasn't left the earth -- but less of it is in ore and more of it is in the alloys that make up food cans.
Same thing with your petroleum example. The carbon and hydrogen that made up the petroleum are still around, except they're now locked up in carbon dioxide and water.
It's easy to extract tin from ore. It's not as easy to extract tin from food cans. Likewise, it's easy to make fuel and lubricants from petroleum, but MUCH harder (e.g. more energy-intensive) to get the same stuff from carbon dioxide and water.
A similar thing happens with water. When you pump it out of the ground to use it, eventually it returns to the environment. The problem is that it doesn't all go back where it came from. It takes a long time for water to cycle back into the water table, so if you pump it out too fast, you can still run out of easily usable water.
That's what "resource depletion" is all about. The elements are still there. They're just not in an easily usable form any more.
Hope that helps.