9.11B - Food security

9.11B(a,b) — Demand and animal farming

Specification point 9.11B is Biology-only, but it is common to both Foundation and Higher tiers. It asks how biology and resource use affect whether people have a reliable food supply.

Food security is not the same as total food production. A country might have enough food overall, yet some people may not be able to obtain or afford it. The factors below can affect availability (how much food exists), access (whether people can obtain it) and stability (whether availability and access can be maintained).

Increasing human population

More people need food. If production and distribution do not rise at least as quickly as demand, less food is available per person and competition can raise prices.

Population growth increases demand; it does not by itself prove that food production has fallen.

Increasing animal farming and increased meat consumption

Livestock require land, water and often crops for feed. Not all feed becomes edible animal biomass: some is not digested, and animals respire, releasing energy for life processes with much ultimately transferred to the surroundings. More crop production may therefore be needed than if suitable crops were eaten directly.

Transfer efficiency varies with species, feed and farming system; 10% is not a universal value. Some animals graze land unsuitable for crops and animal foods can contribute useful nutrients.

Increased fish consumption

Greater demand may increase capture of wild fish, reducing stocks if removal exceeds reproduction. Expanding fish farming can add supply but may require feed, water and land and can allow disease, escapes and nutrient waste to affect wild populations.

Sustainable fisheries and well-managed aquaculture can supply food; the outcome depends on management rather than the word farmed or wild.

9.11B(c,d) — Pests, disease and environmental change

Food supply becomes less stable when the organisms that produce it grow, survive or reproduce less successfully. A pest damages a crop or stored food; a pathogen causes disease. A pest can carry a pathogen, but these terms name different roles.

New pests and pathogens

Pests eat or damage crops and stored food. Pathogens infect crops, livestock or farmed fish, causing disease, death, reduced growth or reduced reproduction. A new arrival may spread rapidly if hosts have little resistance or control measures are not ready, lowering yield and making supply less stable.

A pest is a damaging organism; a pathogen causes disease. The terms are not interchangeable.

Environmental change caused by human activity

Human-caused climate change alters temperature and rainfall and increases risks from heat, drought, floods and changing pest/pathogen ranges. Soil erosion, habitat damage and water pollution can also reduce the land, water and populations able to produce food.

Effects differ among places and species. A change may benefit one crop locally while increasing wider or longer-term risk.

9.11B(e) — Resources, costs and access

Even when farming methods are biologically effective, land and inputs have competing uses and costs. Follow the pressure through to food output or affordability.