" But let me point out that our own natures have come throug in some wonderful ways.... "

Amos...this is about the first time I can remember disagreeing with you in some basic attitude & approach.

yep, we ARE an amazing and inventive bunch, and we have solved problems and pulled ourselves up by our own bootstraps in medicine, physics, agronomy, genetics and many other fields that have both lengthened and enhanced our lives, and I do NOT consider gloom and pessimism to be my favorite recreation, but we never HAD 6 billion people before...and so far, we have not had to deal with 8 billion or 12 billion. What will it be like when there are 79 trillion? ...Oh, that's silly, huh?...maybe 22 trillion? No?..well, when DO we stop...and how? We sure DO need to continue to study all the "interlocking systems" and the forces and solutions, but some things will bite you hard if you guess wrong about how careless to be about them.

I could go on, but I will just note the old joke of the optimist who fell off the observation deck of the Empire State Building...as he passed the 74th floor, he was heard to shout.."well, so far, so good!"