5.2 Agriculture and food

Earth's surface is mostly ocean. Of the roughly 29% that is land, a significant portion is glaciated or barren and cannot support agriculture or most ecosystems. The land that remains, referred to as habitable land, is already under enormous pressure.

Around 70% of ice-free land is used for agriculture and forestry combined. Of that agricultural area, livestock farming occupies close to three-quarters, with crop cultivation concentrated on the most fertile portions. This distribution matters because not all land is interchangeable. Steep slopes, shallow substrates, and nutrient-poor soils rule out arable cropping; such land is typically put to pastoral use instead, if it is used at all.

The pressure on this fixed resource has intensified sharply. Global population grew from roughly 3 billion in 1961 to 8 billion by 2022, and the UN's 2022 medium variant projects a peak of around 10.4 billion in the 2080s. As population rises, the amount of agricultural land available per person falls. At the same time, growing middle-income populations in many countries are shifting toward diets richer in meat and dairy, a change sometimes called the nutrition transition, which further amplifies demand on land.

Production has largely kept pace through intensification rather than expansion. More fertilizer, more irrigation, mechanization, and high-yielding crop varieties have driven yield gains on existing farmland. The scope for expanding the agricultural frontier without destroying high-value ecosystems is limited, so intensification will remain the primary lever, with all the sustainability trade-offs that entails.

Land-use decisions are rarely neutral. When governments, corporations, or development agencies allocate land for commercial agriculture, urban expansion, or industrial projects, the groups with the least political power typically bear the greatest cost.

The people most likely to be displaced or dispossessed include indigenous communities whose land rights may be customary rather than formally registered, women farmers in societies where property law favors men, and low-caste or low-income rural communities who lack the legal standing or economic resources to contest decisions made above them. These groups commonly rely on land not only for food but for cultural continuity, fuelwood, medicinal plants, and water access.

Gender inequality is a specific and well-documented dimension of this problem. Women provide around 50% of agricultural labour in Sub-Saharan Africa and South-East Asia yet frequently cannot own or inherit the land they work. Limited access to credit, education, and markets reduces productivity. Research suggests that equalizing women's access to productive resources could raise yields on their farms by 20–30% in low-income countries, with knock-on benefits for child nutrition.

This example illustrates how large-scale land acquisitions, sometimes called land grabs, can transfer resources away from subsistence users to commercial interests with no guarantee of the promised benefits. Marginalized groups have less capacity to absorb such shocks, making adequate land rights a prerequisite for their food security and resilience.

Global agriculture produces enough food to feed the current world population, and by some estimates could feed several billion more. Hunger persists not because of an absolute shortfall in production but because food is not distributed equitably and large quantities are lost or wasted before they reach people who need them.

Between 690 and 780 million people were undernourished in 2022, even as food surpluses existed elsewhere. Production is concentrated in a handful of major agricultural nations, and many poorer countries depend on imports they cannot always afford at prevailing prices. Undernutrition and overconsumption coexist in the same global system.

At least one-third of all food produced globally is estimated to be wasted or lost. It is useful to distinguish where in the chain this happens:

• Food loss occurs between harvest and retail. In lower-income countries, inadequate storage, lack of refrigeration, poor transport infrastructure, and pest pressure mean that grains, legumes, fruits, and vegetables deteriorate or spill before reaching a market.
• Food waste occurs at the retail and consumer end. In higher-income countries, supermarkets reject produce for cosmetic reasons, consumers over-purchase, portion sizes are generous, and date-labelling causes unnecessary disposal. UK retailers alone generate around 1.6 million tonnes of produce waste annually.

Wasted food represents wasted land, water, energy, and labour, and generates greenhouse gas emissions as it decomposes. Connecting food waste to these broader resource flows is important for any systems-level analysis.

SDG 12.3 (under Sustainable Development Goal 12: Responsible Consumption and Production) specifically targets halving per-capita global food waste by 2030, distinguishing between loss in the supply chain and waste at the consumer level. SDG 2 (Zero Hunger) addresses the availability and nutrition side of the same problem.