E N V I R O N M E N T A L S C I E N C EC H A P T E R 1 5 S E C T I O N 1

FEEDING THE WORLD

FEEDING THE WORLD

• Famine• Widespread starvation caused by a shortage of food.• Occurred in 1985 in Ethiopia due to lack of rain, loss of

soil, and war.

• By 2050, the world’s farmers will need to feed about 9 billion people.• 50% more than they feed today.

HUMANS AND NUTRITION

• Food is necessary as a source of energy and to build and maintain body tissue.

• Major nutrients we get from food are carbohydrates, proteins, and lipids.

• Need smaller amounts of vitamins and minerals.

HUMANS AND NUTRITION

• Malnutrition• Do not consume enough Calories.• Do not eat a sufficient variety of foods to fulfill all of the

body’s needs.• Many forms of malnutrition.• Protein-energy malnutrition can affect the normal physical

and mental development of children.

HUMANS AND NUTRITION

• Sources of Nutrition• Diet – the type and amount of food that a person eats.• Healthy diet maintains a balance of the right amounts of

nutrients, minerals, and vitamins• Grains are the most produced worldwide (carbohydrates).

HUMANS AND NUTRITION

• Sources of Nutrition

HUMANS AND NUTRITION

• Diets Around the World• People generally consume the same major nutrients and

eat the same basic kinds of food.• Diets vary by region• People in developed countries eat more food and a larger

proportion of proteins and fats than those in less-developed countries.

HUMANS AND NUTRITION

• Diets Around the World

THE ECOLOGY OF FOOD

• Food Efficiency• The measure of the quantity of food produced on a given

area of land with limited inputs of energy and resources.• Basically, producing large amounts of food with little

negative impact on the environment.

THE ECOLOGY OF FOOD

• Food Efficiency• On average, more energy, water, and land are used to

produce a Calorie of food from animals than to produce a Calorie of food from plants.

• Animals are usually fed plant matter.• 10% of the energy from the plant is stored in the animal.• Land is more efficient when used to grow crops.

THE ECOLOGY OF FOOD

• Old and New Foods• Yield – the amount of food that can be produced in a

given area.• Researchers hope to improve the efficiency of food

production by studying plants and animals with high yield.• Want organisms that can survive in various climates and do

not require large amounts of fertilizer, pesticides, or fresh water.

WORLD FOOD PROBLEMS

• Poverty• Malnutrition is almost entirely a result of poverty.• The world’s hungry are nearly all farm workers and

subsistence farmers (grow enough only for local use).• Generally do not have access to enough water for

irrigation.• Most live on an income of less than $1 per day.• Mainly in Africa, Asia, and the mountains of South

America.

WORLD FOOD PROBLEMS

• More Income and More Food• Number of people living in extreme poverty has declined

by nearly a half billion since 1980.• Rapid economic development in East Asia (China and

India).• Grain production has not grown as fast as the population.

WORLD FOOD PROBLEMS

• More Income and More Food

THE GREEN REVOLUTION

• Between 1950 and 1970, Mexico increased its production of wheat eight-fold and India doubled its production of rice, without increasing the area of farmland used.

• New varieties of grain allowed this.

• Mostly from large farms.

• Still not improving much for subsistence farmers.