Regarding the "Environmental space" thread, I mentioned that this
book is chock full of stats about land and food:
Pimentel, D. and M. Pimentel (eds), Food, Energy, and Society,
Revised Edition. 1996: University Press of Colorado.
See chapter 12 especially, which the editors themselves wrote. Quote
from p. 149:
"Land for Food Production
More than 99 percent of the world's food supply comes from the land.
Worldwide, about 1.5 billion ha of arable land are cultivated to
produce food (Lai and Pierce, 1991). The global supply of arable land
is 0.27 ha per capita; in the United States 0.6 ha per capita are
cultivated to produce our relatively high animal protein and high
calorie diet (Lai and Pierce, 1991). By the year 2025 arable land per
capita worldwide will decline to a meager 0.2 ha and to only 0.1 ha
by 2100. This estimate assumes there will be no further degradation
in the quality of arable land.
During the past 40 years, about 30 percent of the world's arable land
has been lost (Pimentel et al., 1995). Current agricultural practices
create considerable topsoil erosion. Its severity depends on the
particular crops planted, methods of culture and management,
topography, rainfall and wind, and other factors (Pimentel et al.,
1987; Lai and Pierce, 1991). Worldwide, erosion and its associated
problems force the abandonment of 7 (Tolba, 1989) to 15 million
(Pimentel, 1993) ha of land each year. This problem is also severe in
the United States. For example, Iowa, which has some of the best soil
in the world, has lost half of its topsoil after being farmed for
about 100 years (Risser, 1981)."
This sounds dire, but as I pointed out in my book, chapter 16, with
cold fusion or some other advanced source of energy plus indoor food
factories we could vastly reduce the amount of land it takes to grow
food. I estimated that we could grow enough to feed the entire U.S.
population in an area the size of greater New York City. This would
not take any major breakthroughs other than the energy source, plus
in vitro meat production, which is making good progress.
- Jed
