Biofuels - The Oxford Topic of Food, Politics, and Society - page 180

Food and Malnourishment
Considering the declining availability of natural resources that support agriculture and
food production, it is evident that both the quality of human life and humanity's survival
are being threatened. Many of these resources, especially those that are finite, such as
fossil fuel, are being depleted by overexploitation. The ongoing rapid human popula-
tion growth impacts all the life-supporting natural resources essential for agriculture
and food production. Human population growth especially impacts cropland per capita
worldwide, which has declined in just the past decade by more than 22% (Pimentel and
Pimentel, 2008), and which continues to decline because of rapid population growth
and ongoing soil erosion and soil salinization. Both soil erosion and soil salinization
cause the loss of about 20 million hectares (ha) each year (Pimentel et al. 2009). Large
forested areas are being cut down to replace some of the lost cropland.
Just before the Green Revolution in the 1950s, the average grain consumption per per-
son in the world was about 250 kilograms (Earth Policy Institute 2008). After the Green
Revolution started, world food production per person started to increase; by 1951, average
grain consumption per capita had increased to 255 kilograms (kg) (Earth Policy Institute
2008), and 1960 it had increased to 272 kg. Then, from 1960 to 1984, per capita grain pro-
duction usually increased each year through 1984 (FAO 2013). Starting in 1984-1985, grain
production per capita started to decline, and continued to decline on average through 2007.
The reason that grains make a sound index of food production is that 80% of world food
comes from grain and 50% of the world's agricultural lands are planted to grain (Pimentel
and Pimentel, 2008). With continuing rapid human population growth, grain production
per capita may continue to decline (Pimentel et al. 2009) if shortages of cropland and water
resources are not dealt with. Increased natural gas supplies, as a result of the technology of
high-pressure hydraulic fracturing of shale formations (fracking), may arrest the decline
in nitrogen fertilizer use. Nitrogen fertilizer, the production of which is heavily dependent
on methane, may remain relatively cheap and available for the foreseeable future.
Because fossil-fuel reserves are projected to continue their decline toward less acces-
sible and less conventional reserves over the next hundred years, and because fossil
energy use accounts for much of the increase in cereal grains and other foods, malnutri-
tion will continue to be a serious problem. The estimated sustainable population for the
world in the absence of fossil fuels is about 2 billion, well below the current 7.2 billion
people (Pimentel et al. 2010; PRB 2012).
World Cropland and Water Resources
More than 99.7% of human food comes from the terrestrial environment, while less than
0.3% comes from the oceans and other aquatic ecosystems (FAO 2002). Worldwide, of
the total 13 billion hectares of land area, the percentages according to use are: cropland,