Food: global supply, insecurity and sustainable food production

Global food supply has roughly tripled since 1960, but 735 million people were still undernourished in 2023 (FAO). The challenge is no longer just producing enough — it's distributing it sustainably.

Global patterns of food consumption

• HICs consume ~3 400 kcal/capita/day (USA 3 700) — overconsumption drives obesity (UK 28 % of adults).
• LICs often <2 200 kcal/capita/day. Sub-Saharan Africa has the highest hunger rates; Yemen, Somalia, S. Sudan face famine.
• Diets globalise — meat consumption surging in NEEs (Chinese pork now ~50 % of global supply).

Factors affecting food supply

• Climate — 50 % of crop variability explained by weather; droughts (East Africa 2022 — 23 m at risk), heatwaves, floods.
• Pests and disease — desert locust swarms (East Africa 2020), wheat rust, banana Panama disease.
• Water stress — 70 % of fresh water goes to agriculture; rivers like the Colorado no longer reach the sea.
• Conflict — Russia–Ukraine war (2022) disrupted ~30 % of global wheat exports, sending prices up 50 %.
• Poverty — even where food exists, some can't afford it.
• Technology — mechanisation, fertilisers, GM crops boost output where adopted.

Food insecurity — impacts

• Famine — when food access fails on a mass scale. Yemen 2017–present; Somalia 2011 (260 000 deaths).
• Undernutrition — stunting in children (149 m globally), cognitive impairment, weakened immunity.
• Soil degradation — overcropping degrades 33 % of global soils.
• Rising prices and unrest — 2007–08 food riots in 30+ countries.

Strategies to increase food supply

1. Irrigation

Doubles yields in dry regions. Egypt's High Aswan Dam (1971) irrigated 2.4 m ha but caused salinisation and silt loss.

2. Aeroponics and hydroponics

Soilless farming with nutrient-rich water. Aerofarms (USA) — vertical lettuce farm, 75× more productive per m² than soil. Resource-intensive but possible in cities.

3. New green revolution

GM crops (golden rice with vitamin A); precision agriculture; drought-tolerant maize (WEMA project — millions of African farmers).

4. Biotechnology

GM cotton (India — Bt cotton boosted yields ~30 %), drought-resistant varieties.

5. Appropriate technology

Practical Action treadle pumps (Bangladesh), zero-grazing units (East Africa), simple grain storage.

Large-scale agricultural development case study — Indus Basin Irrigation Scheme (Pakistan)

• One of the world's largest — 14 m ha irrigated.
• Diverts water from Indus and tributaries via dams (Tarbela), barrages and canals.
• Successes: Pakistan now exports rice and cotton; agricultural employment for 40 % of population.
• Problems: 25 % of irrigated land salinised or waterlogged; politically tense between provinces; threatens the Indus Delta (mangroves dying).

Sustainable food production

• Organic farming — no synthetic fertilisers/pesticides. UK 3 % of farmland (2022). Lower yields (~20 % less) but better soil and biodiversity.
• Permaculture — mimics natural ecosystems; perennial crops; works with local conditions.
• Urban farming — Detroit's empty lots converted to community farms; 1 600+ urban farms in Detroit.
• Sustainable fishing — Marine Stewardship Council certification; quotas; protected zones.
• Buy local / seasonal — cuts food miles.
• Reduce meat — 1 kg of beef requires ~25 kg of feed and ~15 000 L of water.
• Reduce food waste — 1.3 bn tonnes/year wasted globally; UK households waste 6.6 m tonnes/year.

Examiner tips

• Always cite a named large-scale scheme (Indus, Nile/Aswan, US Imperial Valley).
• For sustainability questions, balance economic gain (yield, jobs) against environmental cost (salinisation, soil loss, biodiversity).
• Use figures: 70 % of fresh water goes to agriculture; UK households waste 6.6 m tonnes/year.