Food – a resource

Why is food important? 1)Source of energy 2)Source of materials for building new cells & structures **malnourishment can lead to other diseases!

5 major causes of starvation… 1)Human population is growing faster than food production

2) Distribution problems – certain countries have plenty of food, but it isn’t distributed to areas where there is less food.

3) Money – lack of money to buy food.

4) Drought – not enough water to grow food crops.

Before & After picture of Drought in South Africa

5) Political instability – causes distribution problems.

What is famine? …is a widespread food shortage that causes starvation & death.

Famine today …mostly exists in countries where political instability & poverty are problems. (Sub- Saharan Africa) The problems have been made worse by repeated periods of droughts and bad farming techniques.

What was the Green Revolution? …the introduction of new varieties of plants & the implementation of new farming techniques.

The Green Revolution Implementation of new farming techniques (less labor intensive, high inputs) Heavy use of synthetic chemicals Better technology (machinery & genetics) Expensive on front end (cost of materials) but has larger yield making the cost per crop less.

Fig , p. 285 Biodiversity LossSoil Water Air PollutionHuman Health Loss and degradation of grasslands, forests, and wetlands Erosion Water waste Greenhouse gas emissions from fossil fuel use Nitrates in drinking water Loss of fertility Aquifer depletion Pesticide residues in drinking water, food, and air Salinization Increased runoff and flooding from cleared land Other air pollutants from fossil fuel use Fish kills from pesticide runoff Waterlogging Sediment pollution from erosion Greenhouse gas emissions of nitrous oxide from use of inorganic fertilizers Contamination of drinking and swimming water with disease organisms from livestock wastes Desertification Killing wild predators to protect livestock Fish kills from pesticide runoff Surface and groundwater pollution from pesticides and fertilizers Belching of the greenhouse gas methane by cattle Loss of genetic diversity of wild crop strains replaced by monoculture strains Bacterial contamination of meat Overfertilization of lakes and rivers from runoff of fertilizers, livestock wastes, and food processing wastes Pollution from pesticide sprays

Positive effects of the Green Revolution… 1)Higher yield (more food produced) 2)Food is produced relatively cheap

Negative effects of Green Revolution… 1)Some couldn’t afford the equipment needed to farm large areas. 2)Increased pollution due to increased use of fertilizers & pesticides. 3)Uses large amounts of water for irrigation.

PRODUCING MORE MEAT About half of the world’s meat is produced by livestock grazing on grass. The other half is produced under factory- like conditions (feedlots). –Densely packed livestock are fed grain or fish meal. Eating more chicken and farm-raised fish and less beef and pork reduces harmful environmental impacts of meat production.

Fig , p. 289 Trade-Offs Animal Feedlots AdvantagesDisadvantages Increased meat production Need large inputs of grain, fish meal, water, and fossil fuels Higher profits Concentrate animal wastes that can pollute water Less land use Reduced overgrazing Reduced soil erosion Antibiotics can increase genetic resistance to microbes in humans Help protect biodiversity

SOLUTIONS: MOVING TOWARD GLOBAL FOOD SECURITY People in urban areas could save money by growing more of their food. –Urban gardens provide about 15% of the world’s food supply. Up to 90% of the world’s food is wasted. Figure 13-26

Solutions: Steps Toward More Sustainable Food Production We can increase food security by slowing populations growth, sharply reducing poverty, and slowing environmental degradation of the world’s soils and croplands.