Global food production is dependent on land-based agriculture. Arable farming, horticulture, livestock farming and other agricultural practices account for around 99 per cent of global calorie supply and 93 per cent of protein supply.
Global agriculture is dominated by a small number of staple crops grown in a handful of breadbasket regions. Over half of the world’s energy (or calories) provided by crops come from wheat, rice and maize. Adding sugar, barley, soybean, oil palm and potato takes the share beyond three-quarters. A few countries – such as the United States, Brazil, Russia and Ukraine – produce the lion’s share of the world’s wheat, maize, rice and soybeans (see Figure 1). Such genetic and geographical concentration increases the vulnerability of food supply to pests, diseases, extreme weather and trade disruptions, the risks of which are expected to increase with climate change and biodiversity losses.
Dependence on a few calorie-dense crops has led to global dietary convergence. These crops are suited to large-scale industrial farming, and their production has increased through support in the form of government subsidies and private research and development as well as through increased trade. This has come at the expense of biodiversity and dietary diversity. While these crops are calorie-rich, they are nutrient-poor, and so diets have become more uniform, more calorific and less nutritious as their consumption has increased. This is contributing to the global obesity pandemic and public-health crisis.1
Meanwhile, nearly 2 billion people worldwide are dependent on food imports, and this is increasing. The global food trade comprises a complex network of flows. Over 20,000 individual international trade flows were recorded in 2015, worth $1.1 trillion. Increased trade has contributed to a falling share of the world’s population with insufficient food supply but it has also exposed billions of people to the risk of disruptions in international food markets, as seen in 2008 and 2011.
Without changes in consumption patterns, global food production must increase significantly to meet the needs of a growing population. The UN Food and Agriculture Organization (FAO) forecasts food demand could increase by 60 per cent by 2050. Other studies forecast even greater increases in crop demand (around 100 per cent) as rising meat consumption translates into greater demand for feed crops.2
Current rates of yield growth are insufficient to achieve such production increases without the further expansion of agriculture (see Figure 2).3 One recent estimate found that business-as-usual increases in productivity could mean over 1 billion hectares being converted to farmland by 2050 (roughly three times India’s land mass), driving 350 million hectares of net deforestation and an additional 8.8 Gt CO2e of annual emissions (roughly three times India’s current emissions).4
Worryingly, yields have plateaued in key producing regions for rice, wheat, maize and soybean, with ‘hotspots’ of stagnation including China and India. Yields are no longer improving on 24–39 per cent of the world’s most important cropland.
While demand growth in China is expected to slow, it will still account for 30 per cent of additional meat demand (mostly for pork and poultry) and over 50 per cent for fish products by 2026. Most of the pork consumed in China is produced domestically, but this relies on imported feed of soy and maize.
India, meanwhile, will drive 54 per cent of additional demand for fresh dairy products over the next decade. Domestic milk production in India is expected to grow by 49 per cent in the same period. By 2026, India will be the world’s largest milk producer, producing a third more than the European Union, the second-largest producer.
Reducing food waste and losses is often presented as one of the best opportunities to tackle the twin challenge of food security and climate change. 24 per cent of food calories produced are lost in the supply chain or wasted during consumption. Half of the food losses in China and the EU occur at the consumption stage. Waste and losses also occur during harvesting, handling and storage. Globally, cutting waste and losses by half would close 22 per cent of the gap between calories available today and those needed by 2050. It would also help alleviate pressure on land and forest, reduce input uses and save energy across the distribution chain. It would also reduce greenhouse gas emissions through reduced production and avoided emissions from landfill.
Another potential game-changer is the deployment of cold-chain logistics and cold storage at scale in developing countries. While not new, these could be particularly effective in remote areas, where the risk of weather damage to crop harvests or food stocks is high. As well as reducing waste, refrigeration and better infrastructure allow for strategic stockpiling that could create a buffer in case of shocks, reduce the risk of food-safety problems such as aflatoxins and improve market access among smallholder farmers.5
Waste also occurs from feeding crops to animals and human overconsumption. The largest inefficiencies in the global food system – comprising all activities associated with food production, processing, distribution and consumption – occur in the livestock sector, where 87 per cent of calories consumed by animals are lost.6 For example, in the United States, feedlots use around 7kg of grain to produce 1kg of beef. Worldwide, humans consume around 10 per cent more calories than would be needed if everyone ate healthily, though this masks huge disparities in over- and undernutrition. Once post-harvest losses, processing, livestock, consumer waste and overeating are included, losses for the global food system exceed 60 per cent of calories produced.
Agriculture results in many health costs. Food production has contributed to worsened water and air quality, with dire consequences for human health. The health costs of air pollution from food grown for export in the United States are estimated at $35 billion – more than the export value of the food produced.7 While there have been no recent estimates of the health impacts of poor pesticide management, over 300,000 deaths per year as a result of this were estimated in the 1980s.8 Of growing concern today is the overuse of antibiotics in the livestock sector, which is contributing to antimicrobial resistance, one of the most serious systemic health risks currently facing humanity.9 Without further regulation, the projected use of antibiotics in livestock production will increase by 67 per cent between 2010 and 2030.10
The growth of the livestock sector has also increased the risk of animal-to-human pathogen shifts. As livestock production has expanded, domesticated animals have become increasingly exposed to wildlife-borne diseases, while humans have become more exposed to diseases among domesticated animals. Climate change and habitat loss multiply these risks. Seventy per cent of new human diseases in recent decades have been of animal origin, including several alarming actual and potential pandemics such as SARS, swine flu and avian flu, raising the prospect that the next global killer will be a virus of animal origin.11
Worse still, the global food system is also failing to deliver nutrition security. One in nine people (815 million) are hungry (i.e. have insufficient calories) and 2 billion suffer from micronutrient deficiencies, while 1.9 billion adults are overweight, of whom 600 million are obese. Mounting evidence links overweight and obesity to diet-related non-communicable diseases (NCDs) such as Type-2 diabetes, heart disease and certain cancers. Economic losses from overweight and obesity may amount to some $47 trillion over the next two decades, before healthcare costs.12 The total losses from malnutrition in all its forms have been estimated at $3.5 trillion a year, or around 5 per cent of global GDP, from economic growth foregone and degraded human capital. This is almost certainly a major underestimation, as it ignores the impacts of malnutrition on learning potential and labour productivity as well as the resulting increased healthcare and education system costs.13
The number of adults worldwide with diabetes increased from 108 to 422 million between 1980 and 2014.14 Should post-2000 trends continue, the number will surpass 700 million by 2025, with 12.8 per cent of men and 10.4 per cent of women diabetic on an age-standardized basis. This implies immense public-health costs. For example, in the United Kingdom, 3.5 million diabetics cost the health service £13.75 billion a year15 (nearly £4,000 per capita). Applying this treatment cost to global forecasts for diabetes results in global healthcare costs for the disease approaching 5 per cent of global GDP in the next decade.
Skyrocketing healthcare costs for obesity-related NCDs threaten efforts to combat other forms of malnutrition. Obesity is rising rapidly in middle- and low-income countries, which have the highest burdens of undernourishment and stunting. The regions with the fastest growing numbers of diabetics are in South, East and Southeast Asia, and obesity is also increasing in sub-Saharan Africa. These trends create a double burden of under- and overnutrition. Increasing healthcare spending on obesity-related diseases may cannibalize resources for targeted nutrition interventions among undernourished households.
Of the estimated 570 million farms worldwide, 475 million are very small (<2ha).16 Industrial farms (>50ha) dominate production in North America, South America, Australia and New Zealand while medium farms (20-50ha) predominate in Europe and developing-country agriculture comprises mainly small (<20ha) and very small (<2ha) farms. These small and very small farms provide over 1 billion jobs and most of the food supply in developing countries.17 However, most of the farmers on them are poor and lack access to secure land tenure, technologies, finance and markets. 57 million people work in fisheries and aquaculture, where women’s roles are often invisible or under-recognized.18
Small farms provide diversity. Food production on them is associated with a diversity of landscapes, crops and nutrients. Historically, as farming has intensified, production has shifted to crops more suited to mechanization, plots have increased in size and diversity has declined. This creates a challenge for agricultural development strategies – how to maintain landscape, genetic and nutritional diversity while increasing access to technologies and capital among smallholder farmers.
One size does not fit all. Despite often considered prevailing wisdom, it is not the case that small farms are inherently better than large farms or vice versa. It is perfectly possible to operate large-scale farming systems that foster landscape, genetic and nutritional diversity as well as provide multiple ecosystem services with minimal environmental cost. Large-scale, intensive monoculture farming has emerged in response to a market and subsidy regime that rewards productivity and specialization (but not ecosystem services) and fails to account for environmental externalities. Large farms could look very different if farmers faced different incentives.
Global food production depends on natural infrastructure and the ecosystem services and livelihoods it provides. Natural infrastructure includes forests and wetlands as well as coastal and ocean habitats. Critical ecosystem services for food production and human survival include provision of clean water and air, pollination, soil conservation, carbon sequestration and nutrient recycling. Natural infrastructure also acts as critical defence against disasters, for example, by providing flood defences, stabilizing soils and creating natural barriers to storm surges. In cities, planned systems of natural infrastructure can provide clean water, regulate storm water runoff and provide cooling and clean air (e.g. living walls and roofs, planting trees).
Scientists warn that the capacity of natural infrastructure to sustain ecosystem services is being threatened, primarily by agriculture. Farming is the most expansive activity in the world, now accounting for 38 per cent of global land area. It is the principal user of freshwater (responsible for 70 per cent of withdrawals)19 and the main driver of deforestation and biodiversity loss.20 It is also a major polluter of air, freshwater and seawater, particularly farming systems that make heavy or poorly managed use of chemical pesticides and fertilizers. It is also a major degrader of soils. It is the main source of nutrient overload from leakage of nitrogen and phosphorus into waterways, for example.21 Environmental externalities from crop production are estimated to be 1.7 times greater than the market value of the crops.22
Overexploitation of wild fish stocks and intensive aquaculture have similarly detrimental effects on marine and terrestrial ecosystems. Unsustainable rates of exploitation in capture fisheries have prompted substantial declines in global fish stocks.23 In aquaculture, effluent drives ocean eutrophication24 while increasing demand for feed is depleting wild fish stocks and creating a new driver of land-use change as feed manufacturers turn to soybean and cereals.25
At the same time, agriculture is highly vulnerable to the environmental pressures it exerts. Habitat loss is degrading pollinator services, with implications for crops important to human nutrition.26 Intensive agriculture is depleting soils, creating a vicious circle of increasing intensification and further land degradation and abandonment, leading the FAO to recently announce there may only be 60 years of harvests left.
Climate change poses a particularly grave threat to food security. It is already thought to be diminishing crop yields, especially for wheat and maize,27 and will have an increasingly detrimental effect on agriculture, particularly in low-latitude developing countries. Production of nutritious foods such as animal products and fresh fruit and vegetables is especially vulnerable to climate change, particularly in developing countries, while new evidence suggests that elevated levels of carbon dioxide will reduce the nutrient content and quality of crops.28 Results of modelling of climate change’s impacts on food prices vary considerably, depending on the underlying model parameters, climate scenarios, baselines, adaptation responses and data employed. However, in the vast majority of cases the models predict higher food prices. The mean of nine different models, all using the ‘business as usual’ emissions pathway of the Intergovernmental Panel on Climate Change, is that global crop prices will be 20 per cent higher in 2050 than they would have been without climate change.29 Food-price increases are likely to have the largest impacts in low-income countries and in poorer households within countries.30
Increasing frequency and severity of extreme weather means more volatile yields and food markets. Climate change will make extreme floods, droughts and heat waves more likely. These events can decimate harvests, and the implications are global when they occur in breadbasket regions. For example, the 2010 heat wave in Russia – found to have been made more likely by climate change31 – triggered a national ban on wheat exports that sent international wheat prices soaring and is widely considered to have played a part in triggering the initial protests that became the 2011 Arab Spring. As can be seen in Figure 3 below, many low-income, food-deficit countries are dependent on the Black Sea region for their imports and are therefore particularly vulnerable to extreme weather there.
Droughts or floods can have catastrophic localized consequences in regions where food insecurity is already high and markets do not function well. Recent history provides some tragic examples. The 2010 floods in Pakistan, caused by a wetter monsoon consistent with climate change predictions, devastated croplands and led to a collapse in rural incomes and a sharp deterioration in food security. One year later, a drought in East Africa – since linked to climate change32 – triggered a regional food crisis affecting 13 million people; in war-ravaged Somalia, over a quarter of a million people died in the resulting famine.
Degradation of natural infrastructure also threatens human health. Roughly one-quarter of the global burden of disease can be attributed to environmental degradation.33 The burning of forests and peatland in Indonesia has increased respiratory problems through worsened air quality, for example. Wild fires from droughts in California and Portugal have caused significant economic losses. Deforestation in the Amazon is altering rainfall patterns, contributing to a lower water table in São Paulo. The anticipated extinction of a third of reef-building corals will threaten the livelihood of millions in coastal communities (through loss of income and food).
Natural infrastructure is critical to regulating the climate. Vegetation, soils and oceans provide immense natural sinks for carbon emissions. Destruction and degradation of these sinks must be brought to a halt if catastrophic climate change is to be avoided, and their capacity to sequester carbon must be increased. This implies urgent action to stop deforestation, restore and expand forests, stop peatland burning and enhance soil carbon, among other steps.34
Can natural infrastructure sequester sufficient carbon and support sufficient food production? Afforestation and reforestation require land, creating tension with future food production. One recent estimate found that using only forests for the carbon removals needed in a typical Paris-compliant emissions pathway could require 970Mha of land by the end of the century – roughly the equivalent of three Indias or a fifth of current global agricultural land. Land requirements for another carbon-removal approach – bioenergy with carbon capture and storage (BECCS) – requires similarly massive amounts of land and could be catastrophic for biodiversity.35
Bioenergy with CCS would work by burning bioenergy crops in power stations and capturing the resultant emissions and storing them underground in geological reservoirs. However, the climate benefits of bioenergy for power are highly questionable, particularly where forests provide the feedstock, raising serious questions about how efficacious this strategy might be at scale.
Strategies for balancing food production, carbon removal and biodiversity exist. Restoration of forests and other carbon-sequestering natural infrastructure can increase biodiversity. Agroforestry can combine food production, forest cover and biodiversity conservation. Increasing soil carbon provides a climate benefit and can also increase yields and resilience, creating a win-win situation. Some speculative technologies such as direct air capture, algae and artificial photosynthesis could provide a means to produce negative emissions or bioenergy feedstocks with minimal land. Arguably, however, changing consumption habits has some of the greatest potential, for example, global adoption of a healthy diet and reductions of food waste by 50 per cent could free up enough agricultural land to accommodate carbon removal, primarily through reduced consumption of meat.36
Livestock production creates a disproportionate environmental burden. While supplying only 18 per cent of calories and 40 per cent of protein, the livestock sector accounts for about half of agriculture’s greenhouse gas emissions and almost 80 per cent of agricultural land use. Livestock farming is the principal cause of habitat destruction37 and the main source of agricultural pollution.38
The growth of the livestock sector has consequences for human health. Livestock farming systems have increased the risk of animal-to-human pathogen transfers, such as swine and avian flu, and increased antimicrobial resistance as discussed above. Overconsumption of animal products is also linked to non-communicable diseases such as cardiovascular disease and several forms of cancer. For example, a recent study39 found that carbon taxes on food would result not only in significant emissions reductions, but also in net reductions in global mortality, driven by lower red-meat consumption.
Overconsumption aside, animal products provide a source of high quality protein and nutrients and increased consumption would be beneficial for human health among malnourished communities in low-income countries. Policies and actions to reduce consumption of animal products on environmental grounds must preserve the space for consumption to increase in communities where it is below healthy levels.
Although crop production represents a more efficient use of resources than meat production, environmental costs are often still high, depending on agricultural practice and location. Examples include palm oil in Indonesia, rice in Asia, maize in China and soybean in South America.
Growth in demand for palm oil has come at the expense of highly biodiverse tropical peatland rainforest. Between 1990 and 2010, nearly two-thirds of oil palm plantations in Indonesia came at the expense of rainforest.40 China, India, Pakistan and Bangladesh have joined the EU as major importers of palm oil, and continuing demand growth is expected to see Southeast Asian oil palm acreage increase by 17 per cent in the next decade. This assumes, however, that the majority of additional demand is met through yield increases, which would mark a significant departure from historical trends of stagnant yields and expansionary production growth.
Methane from rice paddies, caused by bacteria living in flooded fields, account for around 10 per cent of agricultural emissions. This is a major source of land-use emissions in Southeast Asia, China, India, and Bangladesh. Farming methods that limit flooding of paddy fields can reduce bacteria growth and the associated emissions.
Maize farming is often associated with heavy fertilizer and pesticide application. For example, runoff from fertilizer use in the corn belt in the United States has contributed to algal blooms in the Gulf of Mexico that starve marine life of oxygen and create a so-called 'dead zone.' While important steps have been taken in the United States to reduce fertilizer application, in China farmers have applied increasing amounts to compensate for declining soil quality. A study comparing fertilizer use in the two countries found that Chinese corn farmers had used six times as much fertilizer as their US counterparts to achieve the same yields.41 For the 17 major staples that underpin global calorie supply, China is estimated to account for about a third of excess fertilizer application and over a quarter of nitrous oxide emissions.42
Expansion of soybean monocultures in South America has driven deforestation and biodiversity loss. The growth in soybean acreage has been driven by rising demand for animal feed. However, in many respects, soybean offers an excellent food crop – it is a far more efficient source of protein than animals and it fixes nitrogen, reducing the need for fertilizers. Encouragingly, the impact of soybean on forests has been dramatically reduced by the Soy Moratorium, a Greenpeace initiative to secure commitments from agribusinesses to refuse soybean grown on recently deforested land. Remote-sensing has allowed this agreement to be effectively monitored and enforced, with recent data showing that soy was responsible for around only 1 per cent of deforestation in the Amazon basin.43
The food system is locked in a vicious circle of increasing production, environmental degradation and rising public health costs. Rising food demand is met by increasing agricultural production at the expense of the environment, focusing on a small number of staple crops that can be produced in large quantities in industrial farming systems. This is reducing biodiversity, depleting soils and polluting air and water. The expansion of farming is driving deforestation and habitat destruction.
This system keeps food prices low but encourages waste. Increasing agricultural productivity has led to long-run declines in real food prices (although market prices ignore the costs of production borne by the environment, which amount to almost twice the market price for staple crops). Lower prices have reduced incentives to avoid food waste. As yields have increased over time, food waste has accelerated (see Figure 6). Policies to incorporate environmental externalities into prices could reduce the environmental footprint of agriculture, shift consumption to less damaging foods and reduce the incentive to waste. However, such policies could harm poor food consumers who spend a larger proportion of their income on food.
This circle is ultimately unsustainable as agricultural production depends upon the ecosystems it is degrading. Yield growth is insufficient to meet forecast demand and yields are stagnating in key crop-producing regions. Soil depletion is increasing and pollinator losses threaten production of crops important to nutrient supply. Climate change is already exerting a drag on yields. The continued intensification and expansion of agriculture is a short-term coping strategy that will eventually lead to food-system collapse.
New demands for land compound these pressures. Rising demand for land from bioenergy crops and BECCS, the bioeconomy and urbanization will compete with food production, forcing agriculture to intensify faster and expand further.
Increasing reliance on a small number of staple crops results in diets that are too high in calories and animal products and lack nutrients. The result is a growing burden of malnutrition that risks diverting resources from targeted interventions to tackle undernutrition and stunting. Further public-health costs occur from pollution of air and water resources, while the livestock sector has increased the risk of animal-to-human disease transfer and antimicrobial resistance.
Agriculture must be radically transformed for environmental, food and nutrition security to be reconciled. The environmental footprint of agriculture must shrink dramatically. Nitrogen and phosphorus pollution must be curtailed, soils restored, greenhouse gas emissions cut and land-use contained (preferably reduced to accommodate more afforestation and reforestation). Each one of these steps presents a formidable challenge, but they must be taken simultaneously, while also increasing and diversifying food supply in a manner that supports the livelihoods of hundreds of millions of poor farmers and agricultural labourers.
Achieving these multiple objectives will require new generations of interventions and solutions targeted at leverage points within the food system. For example, disruptive technologies could help to improve soil carbon sequestration, to decouple meat production from land-use, to decarbonize food chains and fertilizer production, to reduce fertilizer demand and to fortify crops. Advances in remote sensing and machine learning provide the means to monitor and enforce land-governance frameworks, develop smart crop insurance products and radically improve supply-chain transparency. Policy must incentivize farmers to increase crop diversity, maintain multifunctional landscapes and provide ecosystem services. It can also encourage consumers to improve their diets, to reduce waste and to reduce the consumption of meat.
Governments have considerable resources and capabilities at their disposal to effect these changes. Current agricultural subsidies in OECD countries are around $230 billion a year, with a similar amount in China.44 These regimes provide the funding and institutional framework in which to create incentives for ecosystem services at national, as opposed to project, scale. Similarly, while no government has intervened to shift dietary preferences for environmental reasons, many have done so on the grounds of public health. This is not uncharted territory.
However, the political economy of the global food system stands in the way of transformative policies and innovative interventions. Market power is highly concentrated. The agricultural sector is core to national income generation in many poor countries, and farm lobbies have remained disproportionately influential in rich countries where it is not. Resistance should be expected at all stages of the food system: from the livestock sector, grain farmers and agribusiness (for which the livestock sector is a major customer, and where farming is predicated on expansive monoculture), and food manufacturers and retailers, which have historically tended to resist government intervention in areas such as labelling, marketing, taxation and product formulation.
Different approaches will be needed in different contexts. In most developing countries, farming is dispersed, and fragmented government capacity is low and farmers are poor. This presents a vastly different set of priorities and challenges to those in countries with industrial farming. Similarly, the challenge of shifting dietary patterns differs greatly from country to country. In developed countries with high meat consumption and high waste, success implies a radical and rapid shift from a quantity-driven food environment to one centred around quality and moderation. In poor countries with low levels of meat consumption and food waste, the focus is likely to be very different.
A clear vision is needed. Experts and advocates are yet to converge around a shared vision for future food systems, with persistent disagreements among those calling for urgent and radical change. Points of contention include the relative merit of grain-fed and grass-fed beef, small versus large farming, the contribution that can be made by certain technologies including genetic modification, CRISPR and synthetic meat, and the role of organic agriculture.