Before Fritz Haber's invention [of synthetic nitrogen] the sheer amount of life earth could support---the size of crops and therefore the number of human bodies---was limited by the amount of nitrogen that bacteria and lightening could fix. By 1900, European scientists recognized that unless a way was found to augment this naturally occurring nitrogen, the growth of the human population would soon grind to a very painful halt. This same recognition by Chinese scientists a few decades later is probably what compelled China's opening to the West: After Nixon's 1972 trip the first major order the Chinese government placed was for thirteen massive fertilizer factories. Without them, China would have probably starved.
I've just finished Sharman Apt Russel's amazing book "Hunger: An Unnatural History," which among other things, discusses the physiological aspects of fasting, the various ways fasting has been used throughout history, and the Western world's response to hunger epidemics.
Here is a bit of what Russel writes about China,
The biggest famine in recorded history also took place in the middle of the twentith century...When [Chairman Mao] wanted China to become a great producer of grain, he collectivized the peasant's farms and insisted on unscientific methods of growing crops that inadvertantly reduce production. Under intense pressure, peasants and officials competed to grow the most food. Harvests were reported at twice, three times, a hundred times their actual yield. Delighted with these inflated numbers, Mao and the party took a percentage of the grain to be stored near urban centers. Sometimes that percentage was the entire real harvest, leaving nothing for the people in the countryside. At the same time China cut its imports of food and doubled its exports. As people began to starve, Mao ignored them.
By the end of 1960, even cities suffered from a lack of food since few farmers had had the strength to plant new crops...Meanwhile, in many areas, the grain stored by the state was left to rot.
Outside China, no one guessed at the extent of the disaster until the mid-1980s when China released census date that researchers could match with other accounts. Thirty to forty million people had starved to death.
Pollen clearly critiques the industrial food complex in Omnivore's Dilemma. I believe that Pollen's position can be summed up succiently from this one paragraph from the first essay in Wendell Berry's book "Another Turn of the Crank." Berry writes,
If communities of farmers and consumers wish to promote a sustainable, safe, reasonably inexpensive supply of good food, then they must see that the best, the safest, and most dependable source of food for a city is not the global economy, with its extreme vulnerabilities and extravagant transportation costs, but its own surrounding countryside. It is, in every way, in the best interest of urban consumers to be surrounded by productive land...
Pollen and Berry make it seem like such a clear cut choice, eat local [reject global] and you will be choosing the more environmental sound, healthier, and more animal-friendly route. To Pollen, our movement away from all these benefits has at least some its origins in the development of fertilizer from synthetic nitrogen, which shifted us away from solar based farming and onto fossil fuel based farming. But the phrase I keep returning to in that passage I quoted above from Omnivore's Dilemma is "grind to a very painful halt." Pollen goes onto to say that one of Haber's biographers "estimates that two of every five humans on earth today would not be alive if not for Fritz Haber's invention." When you put that "painful halt" in the context of very real famines that have occurred, that are occurring, during our lifetimes, I feel less certain about what my food choice mean and if I can live with what they might mean.