Wednesday, April 30, 2014

Moving Up the Food Chain: Hitting Peak Meat?

There has been a persistent cadre of experts who have warned that the world’s population is about to exceed the world’s capability to feed that population. Their arguments have received less attention of late because their previous predictions have thus far been overly pessimistic. Nevertheless, just because the timing was wrong, it doesn’t mean the ultimate prediction is wrong.

Consider the recent predictions for population growth derived by the United Nations (UN): World Population Prospects: The 2012 Revision. The current world population is about 7 billion. The best guess of the future population places it at 10.85 billion in 2100, within the lifetime of a person born today. That is a significant 55% increase yet to come. However this is only an estimate. The UN dataset contains a range of possibilities from 6.75 billion to 16.64 billion (-4% to +238%). Consider what the population would be if the world went on its merry way procreating at the same rate as now; the UN’s constant fertility estimate would yield a population of 28.64 billion (+409%) in the year 2100. Human behavior must change considerably if we are to avoid a Malthusian future.

One way or another, the world is going to experience a great increase in the demand for food. It will probably be due to a large increase in the world’s population as well as a change in the type of food product desired.

It is not widely recognized that total population does not necessarily provide the greatest leverage on food production. Of perhaps greater importance is the type of diet that people aspire to. Humans have always had a desire for more meat than has been available. As the population has become wealthier, on average, meat consumption has increased. Much of agricultural production is aimed not at feeding people directly, but at feeding the animals that produce the meat we so much enjoy.

Lester R. Brown refers to this willingness to spend more of one’s income on animal products as "moving up the food chain." Brown discusses the issues related to food production in his book Full Planet, Empty Plates: The New Geopolitics of Food Scarcity.

"Worldwide, roughly 35 percent of the 2.3-billion-ton annual grain harvest is used for feed. In contrast, nearly all of the soybean harvest ends up as feed. Both pork and poultry depend heavily on grain, whereas beef and milk production depend more on a combination of grass and grain."

If we want meat we must feed an animal to create the meat. If we want affordable meat we must mass produce it in an industrial setting: factory farms where animals of a given species are herded together and fed a mixture of feed (mostly grain, no matter what their natural diet might be) and chemicals needed to aid digestion, stimulate weight gain, and to avoid diseases. The cost of meat then is closely proportional to the amount of food the associated animal consumes.

"A steer in a feedlot requires 7 pounds of grain for each pound of weight gain. For pork, each pound of additional live weight requires 3.5 pounds. For poultry it is just over 2. For eggs the ratio is 2 to 1. For carp in China and India and catfish in the United States, it takes less than 2 pounds of feed for each pound of additional weight gain."

And cost does matter.

"Recent production trends give some sense of where the world is headed. Between 1990 and 2010, growth in beef production averaged less than 1 percent a year. Pork, meanwhile, expanded at over 2 percent annually, eggs at nearly 3 percent, and poultry at 4 percent. Acquacultural output, which sets the gold standard in grain conversion efficiency, expanded by nearly 8 percent a year…."

Brown puts the agricultural demands of a meat-heavy diet in perspective.

"Comparing grain use per person in India and the United States provides some idea of how much grain it takes to move up the food chain. In low-income India—where annual grain consumption totals 380 pounds per person, or roughly one pound a day—nearly all grain must be eaten directly to satisfy basic food energy needs. Only 4 percent is converted into animal protein."

"The average American, in contrast, consumes roughly 1,400 pounds of grain per year, four fifths of it indirectly in the form of meat, milk, and eggs. Thus the total grain consumption per person in the United States is nearly four times that in India."

As the population of India increases its wealth, the demand for meat, milk, and eggs is going to increase—a trend that Brown tells us has already been observed.

A more graphic perspective on what moving up the food chain would mean if all humanity attempts to do it is provided by Chandran Nair, who is concerned that world resources cannot maintain such a level of food production.

"….here is an interesting stat. Americans today consume something like 9 billion birds per year. Asia with a population of about over 10 times that today consumes about 16 billion birds. If Asian meat consumption increases as it is projected to, Asians in 2050 will consume something like 200 billion birds. This again is not going to be possible because on that journey to these levels of consumption, we will see a huge amount of collapse in terms of the ecological systems that we are very much dependent on here."

Brown has published an article at the Earth Policy Institute website that illustrates this effect in action as China attempts to keep up with the demand for its favorite meat—pork: Can the World Feed China? China has labored mightily to be self-sufficient in grain production, but it just cannot keep up with demand.

"Since 2006, China’s grain use has been climbing by 17 million tons per year….For perspective, this compares with Australia’s annual wheat harvest of 24 million tons. With population growth slowing, this rise in grain use is largely the result of China’s huge population moving up the food chain and consuming more grain-based meat, milk, and eggs."

"In 2013, the world consumed an estimated 107 million tons of pork—half of which was eaten in China. China’s 1.4 billion people now consume six times as much pork as the United States does. Even with its recent surge in pork, however, China’s overall meat intake per person still totals only 120 pounds per year, scarcely half the 235 pounds in the United States. But, the Chinese, like so many others around the globe, aspire to an American lifestyle. To consume meat like Americans do, China would need to roughly double its annual meat supply from 80 million tons to 160 million tons. Using the rule of thumb of three to four pounds of grain to produce one pound of pork, an additional 80 million tons of pork would require at least 240 million tons of feedgrain."

China, similarly to most agricultural producers, is already growing about as much grain as possible.

"Where will this grain come from? Farmers in China are losing irrigation water as aquifers are depleted. The water table under the North China Plain, an area that produces half of the country’s wheat and a third of its corn, is falling fast, by over 10 feet per year in some areas. Meanwhile, water supplies are being diverted to nonfarm uses and cropland is being lost to urban and industrial construction. With China’s grain yield already among the highest in the world, the potential for China to increase production within its own borders is limited."

China is not the only country attempting to move up the food chain.

"China is not alone in the scramble for food. An estimated 2 billion people in other countries are also moving up the food chain, consuming more grain-intensive livestock products. The combination of population growth, rising affluence, and the conversion of one third of the U.S. grain harvest into ethanol to fuel cars is expanding the world demand for grain by a record 43 million tons per year, double the annual growth of a decade ago."

Brown’s book is devoted to detailing the reasons why food production is having a difficult time keeping up with demand. Among the reasons discussed are lack of water for irrigation, little new land to cultivate, rising temperatures, and diminishing returns in terms of productivity gains.
He is greatly concerned about the tendency to use water in an unsustainable manner because the ability to produce food is tied to the water supply. If water usage is unsustainable, in terms of drawing down water supplies faster than they can be replenished, then food production is unsustainable. He refers to such a condition as living in a "food bubble."

"We live in a world where more than half the people live in countries with food bubbles based on overpumping [of water]. The question for each of these countries is not whether its bubble will burst, but when."

Dramatic gains in grain production have come from increased productivity of existing cultivated land. Those improvements seem to have played out leaving many countries with stagnant farm yields.

"The keys to this phenomenal expansion were fertilization, irrigation, and higher yielding varieties, coupled with strong economic incentives for production."

"Impressive though the growth is over the last 60 years, the pace has slowed during the last two decades. Between 1950 and 1990, the world grain yield increased by an average of 2.2 percent a year. From 1990 to 2011, the annual rise slowed to 1.1 percent. In some agriculturally advanced countries, the dramatic climb in yields has come to an end as yields have plateaued."

Farmers are already using more fertilizer than the land can accommodate in order to get the last bit of yield. As a result, the excess is running off and entering our water systems. This pollution becomes not only a human health hazard, but a powerful disrupter of aquatic ecosystems that we also depend upon for food supply.

Global warming is also an issue going forward. Plants have evolved to thrive in a narrow range of temperature and other climatic conditions. Rising temperatures and changing weather patterns can have a significant effect on crop productivity.

"High temperatures interfere with pollination and reduce photosynthesis of basic food crops. The most vulnerable part of a plant’s life cycle is the pollination period. Of the world’s three food staples—corn, wheat, and rice—corn is particularly vulnerable."

"….as temperature rises, photosynthetic activity in plants increases until the temperature reaches 68 degrees Fahrenheit. The rate of photosynthesis then plateaus until the temperature reaches 95 degrees Fahrenheit. Beyond this point it declines, until at 104 degrees Fahrenheit, photosynthesis ceases entirely."

Concerns about rising temperatures have sent investigators off to look at historical data correlating crop production with correlated temperature history. Brown describes two studies, one of which concluded:
"….a 1-degree-Celsius rise in temperature above the norm during the growing season lowers wheat, rice, and corn yields by 10 percent."
A second study of corn and soybeans yields concluded that a similar rise in temperature would diminish yields by 17 percent for each crop.

Brown also discusses the issues of soil erosion, desertification, and the conversion of cultivatable land to non-food crops, but the picture should be sufficiently clear by now: large increases in grain production will be difficult to attain. Not everyone will be able to enjoy the diet they might prefer.

Brown predicts that food prices will rise and become more volatile as demand increases. He expects this to lead to more political unrest, particularly in countries where food cost is a major budgetary component. He expresses his concerns in his conclusion to the article about China and grain demand.

"The world is transitioning from an era of abundance to one dominated by scarcity. China’s turn to the outside world for massive quantities of grain is forcing us to recognize that we are in trouble on the food front. Can we reverse the trends that are tightening food supplies, or is the world moving toward a future of rising food prices and political unrest?"

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