renewable resources?

".. they will not have the chance to leave the planet and spread out through
the Galaxy either."

From: Bill Keiser
Date: 2 Jun 2009 17:44
Subject: [andorprojex] renewable resources?
To: andorprojex@yahoogroups.com

just a mind game based on some things i've seen:

some optimistic long range ideas say that we might wreck the world as we
know it and drop back to the stone age, but eventually in a few centuries,
we will come back in force once again and rebuild civilization, or the
cockroaches, or chipmunks, or someone else will.
unfortunately, this ignores what we have done to the resources of this
planet. someone might rebuild civilization again, but not a technological
one. this may actually be a good thing, come to think of it.

a couple hundred years ago, most of the necessary materials for technology
were readily available at the surface of the planet, oil, coal and iron ore
are probably the main 3. all you had to do was shovel or scoop them up where
they intersected the surface. all those are now long gone. they have to be
mined with high tech, high energy mining processes. there might be residual
bits here and there, but the massive amounts that we use now will not be
easily mined anymore.
all the petroleum and coal will have been burned up and will take another
100 million years or so to restore.
all the steel and iron is now easily accessible in scrap yards or our old
skyscraper ruins, but after a few centuries, that will have all crumbled to
rust and will have been washed to the bottom of the oceans.
the towering massive civilization we have now is the one and only chance.
earth's children will never again have the opportunity to sprawl over the
planet with overpopulation and waste. on the other hand, they will not have
the chance to leave the planet and spread out through the galaxy either.

bill keiser