They also say
"Although it is possible to imagine generating
human welfare without natural capital and ecosystem
services in 'space colonies', this possibility is
too remote and unlikely to be of much current
interest. In fact, one additional way to think
about the value of ecosystem services is to
dteermine what it would cost to replicate them
in a technologically produced, artificial
biosphere. Experience with manned space
missions and with Biosphere II in Arizona
indicates that this is an exceedingly
complex and expensive proposition. Biosphere I
(the Earth) is a very effective, least-cost
provider of human life-support services."
No figures are provided in support of these
claims about space-colony economics.
-mitch
http://www.thehub.com.au/~mitch
----- End of forwarded message from Mitchell Porter -----