ENV200 Chapter 7 Notes

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University of Toronto St. George
School of Environment
Romila Verma

CHAPTER 7 – FOOD AND AGRICULTURE [7.2] HOW MUCH FOOD DO WE NEED? A healthy diet includes the right nutrients ­ Malnourishment = nutritional imbalances caused by a lack of specific nutrients in conditions of extreme food shortages o Kwashiorkor = protein and calorie deficiency; bloated belly and discolored hair and skin o Marasmus = protein deficiency; thin and shriveled ­ Vitamin A, folic acid, and iodine are more widespread problems o Vitamin A and folic acid are found in dark green leafy vegetables o Iodine is essential for synthesis of thyroxin  Thyroxin = an endocrine hormone that regulates metabolism and brain development  Developed countries have largely eliminated this problem by adding iodine to table salt o Neurological problems = folic A deficiency o Blindness = vitamin A deficiency o Premature death = vitamin A deficiency o Goiter = iodine deficiency; swelling of the thyroid gland ­ Starchy foods form the bulk of the diet for poor people, but low in several essential vitamins and minerals ­ Genetic engineering of common foods (e.g., golden rice to include a gene for vitamin A) o Effort to deliver crucial nutrients o Too expensive for poor populations o Herbicides needed to grow the golden rice kill the greens that villagers rely on to provide their essential nutrients ­ Harvard food pyramid o Foundation of regular exercise o Mainly fruits, vegetables and whole grains o Moderate amounts of eggs, fish, poultry, nuts, and dairy products o Modest amounts of meat and oils  Fats are essential for healthy skin, cell function, and metabolism ­ There are probably more overweight people than underweight people o Not limited to richer countries o Obesity and associated diseases (e.g., heart attack, stroke, diabetes, hypertension, gallbladder disease, osteoarthritis, respiratory problems, and some cancers) is spreading worldwide o Food insecurity and poverty can contribute to obesity More production doesn't necessarily reduce hunger ­ Most strategies for reducing world hunger include: o Increasing efficiency of farm production o Expanding use of fertilizers and improved seeds o Converting more unused land or forest to agriculture ­ Lack of food production and supply is not necessarily the principal cause of world hunger ­ Better food use and distribution may be the answer to global hunger o For most farmers in the developed world, overproduction threatens prices for farm products  must reduce food supplies and stabilize prices  send millions of food aid to developing areas every year  shipments of free food destabilize farm economies in receiving areas  prices for local products collapse  political corruption can expand if war lords control distribution ­ There are inefficiencies in food use o Food is spoiled in storage and transit, used inefficiently, or thrown away after preparation o Inefficient foods = foods require more animal feed than is produced in food (e.g., meat) ­ Two newer cause of global hunger o International financial speculation on food commodities  Food is a globally traded commodity  Free from restraints, so traders gamble on the value of future crops o Increases the price of current crops well beyond their actual value o Increases the price of farm land o Biofuel production Biofuels have boosted commodity prices ­ New policies promoting biofuels o Increased food prices due to increased demand  Using crops such as soy, corn, palm oil, or sugar cane to drive our cars is an important strategy for supporting farm economies in wealthy countries o Increased global production of these crops ­ Debate about the environmental and economic costs and benefits of biofuel production o Net energy loss (e.g., more energy to produce biofuels than is provided in fuel) o Not economically viable without heavy subsidies for growing and processing crops (e.g., especially ethanol) o However, plant oils can be burned directly in most diesel engines (e.g., net energy gain) Do we have enough farmland? ­ We currently produce more than enough to feed the world ­ We probably do have enough farmland to feed more people than currently live on earth ­ Clearing new farmlands is harder o Tropical soils often are deeply weathered and infertile  Makes poor farmland unless expensive inputs of lime and fertilizer are added o Uncultivated land is too steep, sandy, waterlogged, salty, acidic, cold, dry, or nutrient-poor  Provides essential ecological services on which farmers depend  Wetlands regulate water supplies  Forests and grasslands support insect pollinators that ensure productive crops ­ Arable land per person has decreased because of population growth ­ Conversion of tropical forests and savannas into farmland continues despite important services o Clearing new cropland has helped increase the world's food production capacity o Land conversions have displaced traditional communities and subsistence farmers [7.3] WHAT DO WE EAT? ­ Of the thousands of edible plants and animals in the world, only a few provide almost all our food o Wheat and rice are staple foods in developing countries o Corn and soybeans are primary staples in the United States  Corn provides corn sweeteners, corn oil, industrial starches, synthetic vitamins, and livestock feed for producing beef, chicken, and pork  Soybeans provide protein and oils for processed foods, and livestock feed Rising meat production is a sign of wealth ­ Meat consumption per capita has grown worldwide because of increased corn and soy production o Meat = a concentrated, high-value source of protein, iron, fats, and other nutrients that give us the energy to lead productive lives ­ Dairy consumption per capita is more than meat consumption per capita o Dairy production per capita has declined o Meat production per capita has doubled ­ Meat is an indicator of wealth o Expensive to produce in terms of the resources needed to grow an animal o Most efficient to least efficient use of grain: Bread > Herbivorous fish > Chickens > Pigs > Cows ­ Confined animal feeding operation (CAFO) = animals are housed in giant enclosures and fed specially prepared mixes of corn, soy, and animal protein for rapid growth o Livestock produce muscle (meat) rapidly, rather than simply getting fat o Turnaround time is getting shorter o High population densities require heavy use of antibiotics, which are mixed in daily feed o Expanded the global market for corn and soybeans Seafood, both wild and farmed, depends on wild-source inputs ­ Seafood is the main animal protein source for many people in developing countries ­ Overharvesting and habitat destruction threaten most of the world's wild fisheries ­ The problem is that too many boats are using efficient but destructive technology o Dead by-catch is dumped back into the ocean o Fishing fleets are heavily subsidized in almost all countries  To preserve jobs  To ensure access in the unregulated open ocean ­ The solution is to establish international agreements on fisheries o Manage fisheries for long-term, sustained production o Improve total food production, fishery employment, and ecosystem stability ­ Aquaculture = fish grown in farm ponds that take relatively little space but are highly productive o Providing an increasing share of the world's seafood o Cultivation of plant-eating fish can be very sustainable o Cultivation of carnivorous fish threatens wild fish populations (and seabird populations) o Net pens = fish-rearing ponds anchored in near-shore areas  Replace mangrove forests and wetlands  Encourage spread of diseases (e.g., feces, uneaten food, antibiotics) into surrounding ecosystems Biohazards arise in industrial production ­ Increasingly efficient production has a variety of externalized (unaccounted for) costs o Land conversion from forest or grassland to crop fields increases soil erosion,
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