Limits to Growth

I have been working with and thinking about world systems since the 70s.  I 
seek information: has anyone updated the computer scenarios featured in 
Dennis Meadows' and the Club of Rome's, Limits to Growth?  I have found 
this 
a provocative book to use with students, but they are now pointing out that 
the information is out of date. Please advise me as to updates or other 
sources which I might find useful in trying to understand global systems 
and 
the future.

Thank you very much,

H. Mark Johnson
Markmarv@aol.com