7.9 Food Security and Agricultural Sustainability

Food security

Food security is typically divided into four components:

• Physical availability is an indication that food exists, somewhere.
• Access to food means that food is available to actual people in their households.
• Food utilization includes nutritional, cultural and social aspects that affect how people are able to benefit from the food they eat. It involves food storage, preparation, how and when it’s eaten, how it’s shared among members of the household.
• Stability measures the ongoing nature of the first three factors – whether political, economic, social, or environmental factors disrupt availability, access, or utilization.

Environmental issues are involved in all of these, in some way, but most of all in physical availability, by affecting food production and in stability, by affecting variability in food production.

The UN report on progress on SDG goal 2 – end hunger – indicates that hunger has increased since 2019, when 7.5% of the world was affected by hunger; 9.1% of the world’s population experienced hunger in 2023.^[1] ] Regionally, Africa has the highest rates of hunger, at 20.4%, but Asia has the highest number of people facing hunger: 384.5 million or more than half the world’s hungry.^[2]

In the US, the federal Department of Agriculture defines “low food security” as a matter of poor diet, rather than a problem of food quantity. “Very low food security” involves “multiple indications of disrupted eating patterns and reduced food intake.”^[3] Both measures have increased since 2021 (Fig 1).

Physical availability of food is affected by local weather and climate trends, as we saw in an earlier section, but also by availability of inputs – for example, fertilizer and energy prices – which in turn are affected by conflicts including the Ukraine-Russia conflict. Government policies can offset or increase the impacts of these factors. Going forward, the US decision to impose steep tariffs in much of the world will undoubtedly affect food availability; China’s decision to stop buying US soybeans is a response to US tariffs that will shift food prices, availability, and stability around the world.

Environmental factors such as weather events and pest outbreaks can affect food access, security and stability. Food safety is affected by contaminants which may enter food chains through air and water pollution, including contaminants and pathogens.

Some of the most important factors affecting food security are outside the scope of this section. Poverty, conflict, government policies, and historical legacies all play large roles in food security. Food loss and waste and other inefficiencies in the food-processing pipeline eliminate about one-third of produced food. The UN Environment Programme reports that “19 per cent of food available to consumers [is] being wasted, at the retail, food service and household levels. This is in addition to the estimated 13 per cent of the world’s food that is lost in the supply chain from post-harvest up to and excluding retail.”^[4]

Lack of data on food production, consumption, loss, and wastage makes it difficult to accurately understand food security. Industrial aspects of food production are relatively well reported, but small-scale agricultural activities are poorly tracked. Summary statistics on global food security are mostly produced by international organizations such as the FAO at infrequent intervals. In addition to a scarcity of accurate information on aspects of food security, we also lack good information linking food need in the future to the capacity to produce food in the future.

Agricultural sustainability – can we feed the world in 2050?

We’ve seen a number of unsustainable aspects of agricultural practice in this chapter, including the factors listed here.

• Loss of topsoil and reduction in soil health due to intensive agriculture and overgrazing
• Eutrophication of fresh water and coastal ecosystems
• Poisoning of native plants and insects, including pollinators and “good bugs”
• Spread of invasive species
• Creation of herbicide-resistant weeds, pesticide-resistant pests, and antibiotic-resistant pathogens
• Loss of significant food in food-web processes of livestock production
• Climate change reductions in agricultural productivity
• Loss of biodiversity as a result of all of these, including biodiversity important to agricultural productivity.

That we can feed the world in 2050 seems, perhaps surprisingly, not to be too much in question. But if we continue to produce food unsustainably, by 2050 we may have so damaged the productive capacity of agricultural lands that we will not be able to produce sufficient food for much longer beyond that.

A 2025 report quantifies the role of food systems in taking the planet towards and beyond the boundaries of the safe operating system of the world (planetary boundaries were introduced in Chapter 1).^[5] The food system currently produces more than 3 times the boundary amount of GHG. It is nearing the boundary of land conversion and amount of agricultural land that is the boundary for intact land. Food systems produce more than twice as much N₂0 as is consistent with healthy stratospheric ozone concentrations and they contribute 25% of the CO₂ emissions responsible for ocean acidification. Nitrogen levels are more than twice the food-system boundary value and phosphorus levels are 156% of boundary values. Water use is approaching boundary values. Synthetic chemicals released without adequate safety testing are >16 times higher than levels that pose low pollution risk. Food systems are a significant part of the threats that are taking the planet out of its safe operating space.

A World Resources Institute summary boils issues related to feeding the world in 2050 down into 3 gaps^[6]:

• a 56% gap in calories produced in 2010 and what will be needed in 2050 (not a straightforward quantity to estimate,^[7])
• a gap of 593 million hectares between land needed for agriculture in 2010 and what may be needed in 2050 (an area about 3/4 the size of Australia), and
• an 11 gigaton GHG-emission gap between emissions predicted for 2050 and what is needed to hold global warming below a 2°C increase, to reduce harm.

The suggested remedies we have seen in this chapter are designed to close these gaps. For example, using more grain to feed people and less to feed livestock, alone, would put a big dent in the land gap. But the proposed remedies are not yet close to closing the gaps, and are not currently predicted to do so by 2050.

We have a solid understanding of how to proceed to reduce food-system impacts, generally, but some approaches take time to implement, and others are unpopular or, even if popular, affect powerful economic and political interests. Support for better practices will require reallocation of funds both to provide greater equality in access to seeds, inputs, and equipment and to offset sunk costs in equipment that may not suit current or future needs. Not only governments and industries must be persuaded to change. Farmers must also be convinced that these changes are needed, as must consumers.

Feeding Africa in 2050 – the extreme case

A major concern in feeding the world going forward is the tremendous inequality of growing population pressure and accompanying increases in food demand. Although Asia has the largest proportion of world population, Africa will contribute the most to population growth throughout the 21st century, with the sub-Saharan population predicted to nearly double between 2020 and 2050, adding more than half of all the additional population on the planet during that interval.^[8] Sub-Saharan Africa also leads the world in poverty, has led the world in violence by states and organizations against civilians since 2013,^[9] and trails the world in organic material and nutrients in soils (Fig 2).^[10][11]

Figure 2 shows suitability of world soils for rainfed (unirrigated) agriculture with only low inputs (fertilizer, pesticides). Africa lacks any of the large native grasslands that characterize the high-productivity agricultural areas of the North American prairies, Argentinian pampas, and Eurasian steppes (shown in dark green) and has a preponderance of soils in the medium and moderate categories.

As with the world food situation, recommendations for feeding Africa in 2050 are available, but they require even greater increases in training, investment, industry and agricultural practice than for the world at large. Not only country-level processes must change, but the continent as a whole would benefit immensely from a coordinated, sustainable, resilient supply chain for all aspects of food production, to eliminate the current dependencies on imports of food and agricultural inputs and on international food aid.

Knowledge Check

Take a moment to complete the short quiz below to assess your understanding of this section. Read each question carefully and refer to the section content as needed. This quiz is not graded – it’s simply an opportunity for you to reflect on what you’ve learned and reinforce key concepts.