On Wed, 9 Apr 2008 10:31:42 -0400, "J. Clarke" wrote:

Note that something that works in Cuba, where the population density
in Havana is such that there is almost 5000 square feet of land for
every resident, is not necessarily going to work where the population
density is more than ten times as high.

Worth noting also that Cuba is closer to the equator and hence has
longer daylight hours pretty much all year and thus can grow more
vegetation than most densely populated cities in OECD countries. I can
imagine Australia and New Zealand coping, but don't hold out high hopes
for some American cities like New York.
--
Ross McKay, Toronto, NSW Australia
"Let the laddie play wi the knife - he'll learn"
- The Wee Book of Calvin