(After a lot of reading and hunting around on the net, I found a great deal of information on this topic. I had never really researched on it before so wanted to make sure that calculations agreed from report to report. Most of them did so I will base my answer on these different reports. This subject is extremely interesting, scary and a bit of a shock as to how much we have abused and taken advantage of this Earth. Though progress as far as technology has been something we make use of and enjoy, we are paying for it in ways I never thought o ....