4.2.2 Dietary change
Supply-side measures to increase production will not be sufficient to meet future demand for food without accompanying interventions to change consumption patterns. A shift in diets – and particularly a transition away from meat-rich diets – could radically alter future patterns of agricultural land use. Scenario-based modelling has shown that completely replacing consumption of animal products with plant-based foods in high-income countries could result in a 29 per cent reduction in associated global cropland use; the same strategy in upper-middle-income countries would reduce their cropland footprint by 12 per cent compared with business-as-usual projections for 2030. Modelling has also indicated that, at a global level, universal adoption of ‘healthy’ diets (limiting but not eliminating animal produce) could reduce the required area of cropland by around 5 per cent by 2050, and that of pasture by around 25 per cent, compared with scenarios involving no dietary changes (see Chapter 6).
While there is broad consensus on the environmental and public health advantages of tackling overconsumption of meat in high-consuming countries, there remains considerable debate around the role of livestock and animal-sourced foods in achieving food and nutrition security, alongside environmental sustainability, in developing countries. A number of studies have attempted to determine the parameters for a diet that is nutritious for all – and culturally and environmentally appropriate – while being deliverable from a food system within planetary boundaries. These studies broadly find that such a diet consists primarily of vegetables, fruits, nuts, wholegrains and unsaturated oils, together with small quantities of seafood and poultry, but includes little or no red meat, sugar or refined grains. Important barriers to the adoption of such a diet nevertheless remain, including its affordability and its appropriateness among different cultures. However, a fuller accounting of the costs of diets (including costs associated with diet-related illness and diet-related impacts on climate change, which are not currently reflected in the price of food) demonstrates that healthy and sustainable diets are the least costly option in most countries.
In countries where consumption of meat is in excess of recommended ‘healthy’ levels – as defined by the World Health Organization or by national dietary guidelines – a range of interventions have been discussed or trialled as potential means of prompting people to reduce their intake. These interventions span a broad spectrum, including information campaigns, ‘nudge’ tactics such as changes to menu and label design, and the use of a ‘meat tax’.
4.2.3 Reductions in food losses and waste
Given the scale of food losses and waste globally – around 13 per cent is lost post-harvest and in the supply chain; and a further 17 per cent is wasted by households, in food services and in retail – reducing these could result in considerable land savings. Based on current trends in crop yields, a 50 per cent reduction in food waste would result in a projected 14 per cent reduction in cropland requirement (and an 11 per cent reduction in all agricultural land use) by 2050, compared with a business-as-usual scenario (see Chapter 6). One estimate suggests that an additional 235 million people could be fed from the crops used to produce consumer-wasted meat products alone. In 2019, the EAT-Lancet Commission on healthy diets from sustainable food systems estimated that, in the absence of radical dietary change, current cropland will be sufficient to meet food demand in 2050 only if food waste is halved and yield gaps are closed by 75 per cent. And as around 10 per cent of all anthropogenic greenhouse gas emissions come from food system processes associated with food that is ultimately lost or wasted, eliminating or minimizing these losses would also have land-sparing benefits by reducing the amount of land needed for compensatory carbon sequestration.
Around 13 per cent of food is lost post-harvest and in the supply chain; and a further 17 per cent is wasted by households, in food services and in retail.
The most effective strategies to tackle food waste and losses will differ from country to country. In countries where waste is concentrated towards the consumption end of the value chain, changes to practices among food manufacturers and retailers will be particularly important: for example, reform of ‘best before’ dates to avoid waste of safe food; or the easing of ‘aesthetic’ standards that currently mean that large volumes of fresh fruit and vegetables are rejected by retailers and their suppliers. Interventions targeted at consumer behaviour may also be needed to effect waste reductions at scale. These could include communication campaigns, changes to food-labelling requirements, and new technologies such as ‘smart’ refrigerators – for example, those that include a camera to enable inventory-taking and planning, or those that alert users when food nears its expiry date.
In countries where access to technologies, infrastructure and transport is lacking, with the effect that food is lost predominantly at the post-harvest and supply chain stages, strategies will need to tackle structural conditions such as energy access at farm level, storage capacity, quality of transport infrastructure, and reliability of cold chain logistics. Greater use of surplus food in animal feed production, either as a direct ingredient or as a feedstock for insect meal, may offer another important means of reducing overall nutrient losses along the food value chain while easing pressure on land use for feed production.
Measures to mitigate food waste at the point of consumption will also become increasingly important as efficiency improves at the point of production and processing. To date, innovations in the storage, transport and conservation of food have already led to lower rates of food loss, and have done much to improve food access and availability. However, in also lowering food prices, such efficiency gains have in turn induced consumers and retailers to waste more food.
4.2.4 Decoupling food production from land use
Innovation has emerged in recent years that focuses on decoupling food production from land use, principally through so-called ‘landless’ systems and novel alternatives to conventionally produced meat. Landless farming encompasses a range of methods to produce food crops in controlled environments. Key among these are hydroponics, where crops are grown in soil-free, suspended ‘farms’ with their roots bathed in a nutrient-rich solution; and aeroponics, in which the roots are sprayed with a nutrient-rich solution. Lighting, humidity and temperature can all be carefully controlled to provide the optimum conditions for plant growth and minimize evaporation, thus conserving water. ‘Landless’ systems are in the early stages of development, and are currently used predominantly for high-value horticultural crops rather than staple cereals. But they have the potential to boost production in land-scarce settings such as cities, as well as in regions where water is limited or soil quality is poor.
Novel alternatives to meat offer a more radical means of decoupling food production from land use, reducing inputs and mitigating agricultural emissions. Plant-based meat substitutes use plant-derived ingredients to mimic the look, taste and texture of meat, while ‘cultured meat’ involves isolating stem cells from an animal and then cultivating these cells in a laboratory or bioreactor with the help of a growth medium. One prominent estimate suggests that replacing half of global animal-product consumption with consumption of plant-based substitutes such as soybean curd (tofu) could reduce agricultural land use by 35 per cent, while a 29 per cent reduction could be achievable if cultured meat is used. (See Chapter 6 for a further discussion of this issue.) Other estimates suggest that production of cultured meat may require a land area as small as 1 per cent of that used to produce conventional meat. Both plant-based imitations and cultured meat are the focus of rapidly growing industries as technologies advance and, in the case of cultured meat, as products begin to enter the market (plant-based substitutes already being more established). In 2021, capital investment in companies making plant-based meat, dairy and egg products amounted to 30 per cent of the all-time total, while investment in cultured-meat companies was up 236 per cent year on year. However, in a more difficult economic context, investments in all forms of meat alternatives have since fallen back.
Production of cultured meat may require a land area as small as 1 per cent of that used to produce conventional meat.
Algae and insects are also increasingly recognized as novel protein sources, with the potential to bring significant land savings in the production of animal feed and biofuel. Algae provide a potential feedstock for biofuel and animal feed, and can also be grown in deserts. Should technological barriers be overcome, industrial algae production could provide 10 times as much feed protein as global soybean production, and meet global liquid fuel demand using an area of land just three times the size of Texas. Farmed insects, which may be fed on waste biomass, can provide a protein source both for direct human consumption and for use in animal feed. They have a much smaller land footprint than conventional animal protein sources: early estimates suggest that the production of 1 gram of edible chicken protein requires two to three times as much land as does 1 gram of edible mealworm protein, while production of 1 gram of edible beef protein uses between eight and 10 times as much land.
4.3 How plausible is a reduced land footprint for food production?
All available evidence suggests new strategies will not be deployed at the pace and scale required to avoid an increase in agricultural land demand and the further degradation of existing agricultural land. Many of the most promising interventions in support of sustainable intensification and the decoupling of food production from land use have yet to be proved at scale. The feasibility of each of the four strategies discussed above – sustainable intensification, dietary change, food loss and waste reduction, and decoupling food production from land use – is also highly dependent on the deployment of one or more of the other strategies in parallel. For example, existing techniques for boosting agricultural yields are unlikely to be enough to match demand growth, so dietary shifts will also be needed to limit overall demand. At the same time, a shift to low- or no-meat diets will likely be difficult to realize without first closing the gap between current and potential crop yields, particularly for fruits and vegetables. And higher yields for plant-based foods are only likely to be realized through increased freshwater use in irrigation.
All available evidence suggests new strategies will not be deployed at the pace and scale required to avoid an increase in agricultural land demand and the further degradation of existing agricultural land.
Significant uncertainties about regional patterns of uptake of these strategies also remain, as do questions as to where each approach (or combination of approaches) should best be deployed to achieve the maximum reduction in land use for food production while supporting global food and nutrition security. The viability of each of the strategies discussed in Section 4.2 depends on considerable shifts in institutional, societal and individual behaviours. Financial, policy and institutional constraints also threaten to slow these shifts and hamper widespread adoption, especially for technology-dependent solutions.
Climate change is likely to increase the area of cultivable land in developed countries in high latitudes, but a combination of trends – urban encroachment on croplands, growing demand for bioenergy production, increased reliance on carbon capture and storage – mean that the use of this land for food production is far from certain. On the other hand, in low-latitude countries where the area of cultivable land is projected to decrease with climate change, and where yields are expected to decline, the area of land under cultivation is forecast to increase substantially. With or without the implementation of the strategies described above, many countries will increasingly look overseas for food production capacity, and land-rich countries where governance is poor will in turn likely see continued widespread land-use change.