5.2 Agriculture and foodIB Environmental Systems and Societies HL: Revision notes

Land is finite while the human population grows. Marginalised groups are more vulnerable if their needs are ignored in land-use decisions. The world produces enough food for eight billion people, but it is not equitably distributed and much is wasted or lost. Food security is the physical and economic availability of food allowing everyone to get the balanced diet they need for an active, healthy life.

Systems vary with soils and climates and with farmers' choices, with economic, social and environmental implications. Nomadic pastoralism and slash-and-burn are traditional techniques that sustained low-density populations.

The Green Revolution (1950s–60s) used high-yielding crops, irrigation, synthetic fertiliser and pesticides to increase food security, and has been criticised for its sociocultural, economic and environmental consequences.

Intensive systems need synthetic fertilisers for commercial productivity, at the expense of sustainability; sustainable agriculture improves fertility by other methods (rotation, compost). Soil conservation techniques bring environmental, economic and sociocultural benefits.

Diets lower in trophic levels are more sustainable. Global strategies for sustainable supply: reduce demand and food waste, reduce greenhouse gas emissions and increase productivity without increasing agricultural land.

(HL) Contrasting agricultural choices often result from differences in local soils and climate.

(HL) Alternative approaches developed in response to the ecological crisis include soil regeneration, rewilding, permaculture, non-commercial cropping and zero tillage. Regenerative farming and permaculture use mixed farming to improve and diversify productivity, for example pigs or chickens to clear vegetation and plough, or mob grazing to improve soil.

(HL) High-tech greenhouses and vertical farming can reach very high productivity and are increasingly important for supplying food to urban areas, but are energy-intensive.

(HL) The sustainability of diets varies with supply chain efficiency, distance food travels, type of farming, techniques and societal diet change.

(HL) Harvesting wild species by traditional methods may be more sustainable than converting land to cultivation.

(HL) Claims that low-productivity, indigenous, traditional or alternative food systems are sustainable should be evaluated against the need to produce enough food to feed the wider global population.

(HL) Food distribution patterns and variations in food quality reflect how the global food supply industry functions and can lead to all forms of malnutrition: diseases of undernourishment and overnourishment.