BG/CH 0493 Environment and Sustainability

Chen Yuan

January 2015

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Chapter 12: Food Production and the Environment

12-1 What is food security and why is it difficult to attain? 12-2 How is food produced? 12-3 What environmental problems arise from industrialized food production? 12-4 How can we protect crops from pests more sustainably? 12-5 How can we improve food security? 12-6 How can we produced food more sustainably?

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Many people in less-developed countries have health problems from not getting enough food, while many people in more-developed countries suffer health problems from eating too much

The greatest obstacles to providing enough food for everyone are poverty, war, bad weather, climate change, and the harmful environmental effects of industrialized food production

12-1 What Is Food Security and Why Is It Difficult to Attain?

Food security

All or most people in a country have daily access to enough nutritious food to lead active and healthy lives

Food insecurity

Chronic hunger and poor nutrition

Causes:

Political upheaval, war, corruption, and bad weather

Poverty Is the Root Cause of Food Insecurity

Macronutrients Carbohydrates Proteins Fats

Micronutrients Vitamins Minerals

Chronic undernutrition Not enough food to meet basic energy needs

Chronic malnutrition Not enough protein or other key nutrients

Famine Severe shortage of food Result in mass starvation, many deaths, economic chaos, and social disruption

Many People Suffer from Chronic Hunger and Malnutrition

Most often vitamin and mineral deficiencies in people in less-developed countries

Vitamin A

Blind

Iron

Anemia

Iodine

Essential for thyroid function

Many People Do No Get Enough Vitamins and Minerals

Overnutrition Excess body fat from too many calories and not enough exercise

Similar health problems to those who are underfed

Lower life expectancy

Greater susceptibility to disease and illness

Lower productivity and life quality

Many People Have Health Problems from Eating Too Much

We have used high-input industrialized agriculture and lower-input traditional agriculture to greatly increase food supplies

Three systems produce most of our food Croplands

Rangelands, pastures, and feedlots 16% on 29% of

Aquaculture 7%

Three main grain crops wheat, rice, and corn

Irrigation supply of water to crops

12-2 How Is Food Produced?

Industrialized agriculture Heavy equipment Large amounts of financial capital, fossil fuels, water, commercial fertilizers, and pesticides Single crop

Goal is to steadily increase crop yield Plantation agriculture cash crops

Primarily in less-developed countries

Increased use of greenhouses to raise crops

Industrialized Crop Production Relies on High-Input Monocultures

Fig. 12-7a, p. 283

Industrialized Agriculture

Uses synthetic inorganic fertilizers and sewage sludge to supply plant nutrients

Makes use of synthetic chemical pesticides

Uses conventional and genetically modified seeds

Depends on nonrenewable fossil fuels (mostly oil and natural gas)

Produces significant air and water pollution and greenhouse gases

Is globally export-oriented

Uses antibiotics and growth hormones to produce meat and meat products

Traditional subsistence agriculture Human labor and draft animals for family food

Traditional intensive agriculture Higher yields through use of manure and water

Polyculture Crop diversity Benefits over monoculture

Slash-and-burn agriculture Subsistence agriculture in tropical forests Clear and burn a small plot Grow many crops that mature at different times Reduced soil erosion Less need for fertilizer and water

Traditional Agriculture Often Relies on Low-Input Polycultures

Crops grown with ecologically sound and sustainable methods

No synthetic pesticides or fertilizers

Has a number of environmental advantages

Usually produces less than conventional agriculture

Organic Agriculture Is on the Rise

Fig. 12-7b, p. 283

Organic Agriculture

Emphasizes prevention of soil erosion and the use of organic fertilizers such as animal manure and compost, but no sewage sludge to help replace lost plant nutrients

Employs crop rotation and biological pest control

Uses no genetically modified seeds

Reduces fossil fuel use and increases use of renewable energy such as solar and wind power for generating electricity

Produces less air and water pollution and greenhouse gases

Is regionally and locally oriented

Uses no antibiotics or growth hormones to produce meat and meat products

Green Revolution increase crop yields Monocultures of high-yield key crops

Rice, wheat, and corn

Large amounts of fertilizers, pesticides, water Multiple cropping

Second Green Revolution Fast growing dwarf varieties

World grain has tripled in production

A Closer Look at Industrialized Crop Production

First gene revolution

Cross-breeding through artificial selection

Slow process

Amazing results

Genetic engineering second gene revolution

Genetic modified organisms (GMOs) transgenic organisms

Crossbreeding/Genetic Engineering Produce New Varieties of Crops/Livestock

Animals for meat raised in: Pastures and rangelands Feedlots

Meat production increased more than sixfold between 1950 and 2010

Increased demand for grain Demand is expected to go higher

Meat Production Has Grown Steadily

Fishery Concentration of a particular species suitable for commercial harvesting

30% are overfished

57% harvested at full capacity

Aquaculture, blue revolution -growing type of food production

Dominated by operations that raise herbivorous species

Fish and Shellfish Production Have Increased Dramatically

Fig. 12-12, p. 287

140

100

120

80 Wild catch

Pro

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on

(m

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on

s o

f m

etr

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40

60

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20 Aquaculture

Year Total World Fish Catch

1950 1960 1970 1990 2000 2010 1980 2020

Grow, store, process, package, transport, refrigerate, and cook (10 times of the food energy)

Mostly nonrenewable energy oil and natural gas

Agriculture uses 20% of all energy use in the U.S.

Amount of energy per calorie used in the U.S. has declined 50% since the 1970s

Industrialized Food Production Requires Huge Inputs of Energy

Future food production may be limited by soil erosion and degradation, desertification, irrigation water shortages, air and water pollution, climate change, and loss of biodiversity Producing Food Has Major Environmental Impacts. Agriculture has harmful affects on:

Biodiversity Soil Water Air Human health

12-3 What Environmental Problems Arise from Food Production?

Fig. 12-13, p. 288

Natural Capital Degradation

Food Production

Biodiversity Loss Soil Water Air Pollution Human Health

Erosion Emissions of greenhouse gas CO2 from fossil fuel use N2O from inorganic fertilizer use, and methane (CH4) from cattle

Nitrates in drinking water (blue baby)

Loss of fertility

Aquifer depletion

Pesticide residues in drinking water, food, and air Salinization

Increased runoff, sediment pollution, and flooding from cleared land Fish kills from

pesticide runoff

Waterlogging Killing wild predators to protect livestock

Desertification

Pollution from pesticides and fertilizers

Loss of genetic agrobiodiversity replaced by monoculture strains

Algal blooms and fish kills caused by runoff of fertilizers and farm wastes

Bacterial contamination of meat

Other air pollutants from fossil fuel use and pesticide sprays

Conversion of

grasslands, forests,

and wetlands to

crops or rangeland

Livestock wastes

in drinking and

swimming water

Soil erosion Movement of soil by wind and water Natural causes Human causes

Two major harmful effects of soil erosion Loss of soil fertility Water pollution

Topsoil Erosion Is a Serious Problem in Parts of the World

Stepped Art

Stable or

nonvegetative

Serious concern

Some concern

Fig. 12-16, p. 289

Desertification Productive potential of topsoil falls by 10% or more

Prolonged drought, human activities

Human agriculture accelerates desertification

Dust bowl Severe wind erosion of topsoil

Drought and Human Activities Are Degrading Drylands

Soil salinization Gradual accumulation of salts in the soil from irrigation water

Lowers crop yields and can even kill plants

Affects 10% of world croplands

Waterlogging Irrigation water gradually raises water table

Can prevent roots from getting oxygen

Affects 10% of world croplands

Excessive Irrigation Has Serious Consequences

Fig. 12-18, p. 292