A 24-hour recall is a dietary assessment tool, commonly used in nutrition research, that consists of a structured interview or standardised questionnaire in which participants are asked to recall all the food and drink they have consumed during the previous 24 hours. In comparison to other common methods such as food frequency questionnaires, 24-hour recalls provide relatively detailed information about participants’ food intakes. Important limitations include the inability to account for day-to-day variations and reliance on participants’ ability to accurately remember the food and drink they have consumed.

Acidification refers to changes to the chemistry of a body of water that make it more acidic over time (i.e. increased hydrogen ion availability). This change in acidity can then affect many other reactions that take place in water, including those important for ecosystem functioning.

Aeration is the process by which air is circulated through, mixed with, or disolved in a liquid or substance.

Agri-food system refers to the constellation of social, political, economic and environmental processes and actors involved in the production, distribution and consumption of food and related agricultural products. It encompasses all varieties of food production including aquaculture, forest-based production, livestock and crops, and focuses on both their biophysical and socio-economic characteristics.

Agricultural intensification is the process of increasing the inputs of agricultural resources (e.g. seeds, labour, fertilisers, pesticides, technologies, knowledge) to increase the level of yield per unit of farmland or pasture. Agricultural intensification is not always clearly or consistently defined and is often confused with the term intensive agriculture. Unlike intensive agriculture, which could be seen as a specific system of agronomy, agricultural intensification is a general process that can apply, in principle, to any type of agricultural production. Examples of agricultural intensification may range from using new pesticides in intensive agriculture to intensifying the use of indigenous and context-specific knowledge in local farming practices. Although agricultural intensification can take many forms, it always involves the intensification of some types of agricultural input with a view to increase levels of yields.

A form of crop farming that is based on the growing of a single crop type on a field at a given point in time. Agricultural monocultures sometimes follow a rotational pattern where different crop types such as maize, wheat or soybeans are grown successively on the same field. The use of agricultural monocultures is typically based on the principle of economies of scale. The principle here is that the costs of inputs such as machinery, labour, fuel, herbicides, fertilisers and land per unit of output (kg yield) can be kept relatively low if the diversity of crops that are grown in an agricultural landscape is minimised. Agricultural monocultures are controversial within the environmental movement. Amongst other things their efficiency is debated and critics point out that the practice of agricultural monoculture can lead to externalities (i.e. costs such as biodiversity loss, water pollution or a lack of resiliency that are not reflected in the final cost of the product) and also for the most part  goes hand-in-hand with ongoing corporate consolidation in the food system.

Agricultural production is the range of practices and approaches that are employed to transform agricultural inputs (e.g. labour, knowledge, land, water, seeds, fertilisers, pesticides) into agricultural outputs (e.g. yields and environmental impacts). Different types of agricultural production include precision farming, agroecology, organic farming, and intensive livestock farming.

Agricultural productivity is the ratio of yields relative to agricultural inputs (e.g. labour, knowledge, land, water, seeds, fertilisers, pesticides).

Agricultural yield is the average net output of agricultural product (e.g. in kCal, grams protein, or net profit) per unit of farmland per year. The total amount of farmland includes all land that is required to generate the output (e.g. also land that is used to grow feeds or to produce manure).

Agrochemicals are chemicals, such as a pesticide or fertiliser that are used in agriculture.

Agroecology is commonly understood as a science, a practice and a movement. As a science, it uses principles from the field of ecology to study the interactions between organisms in agroecosystems. It is often associated with transdisciplinary and action-oriented research, and the study of the entire food system. As a practice, agroecology combines indigenous and traditional knowledge, and scientific research, to generate productive, sustainable and resilient farming systems with minimal external inputs. This is achieved by optimizing processes and interactions occurring within agroecosystems, for example through crop rotations, cover crops, polycultures, crop-livestock integration, agroforestry and minimal tillage. It is generally associated with smallholder farming, and focuses on the production of nutritious food suitable for personal consumption and local markets. As a movement, agroecology seeks to address power imbalances within the food system, and generate a more just and equitable food system based on the principles of food sovereignty.

Agronomy is a science and practice seeking to understand and improve the cultivation of plants for food, fibre and fuel. Agronomists focus on a variety of factors relating to crop production, including yield, disease, climate and soil.

Alternative food movements generally exist to challenge the current negative consequences of food systems. Fair trade, organic, food justice, food sovereignty, vegan and vegetarian movements can all be seen as offering alternatives to the status quo and as such form part of the "alternative food movement;" it can be said that there are several movements, rather than just one.

'Alternative protein' is a phrase used to describe either specific protein sources (such as microbial mycoprotein) high-protein foods which can be considered alternatives for animal proteins and animal source foods. The term is most typically used of proposed novel foods, but in the context of discussions of radical changes to the food system to achieve greater sustainability is also used of traditional foods whose consumption could be increased. Some foods commonly referred to by the term alternative proteins are insects, ultra-processed plant-based meat substitutes, cultured meat, single-cell proteins, and minimally processed legumes.

Anaerobic processes occur in the absence of oxygen. For example anaerobic respiration occurs when oxygen is not present.

Animal ethics attempts to use moral reasoning to move beyond existing norms (e.g. regulations that may have been influenced by stakeholders with differing interests) and propose directions of change based on specific ethical theories. The two dominant families of ethical theories around human relationships with other animals are rights theory and utilitarianism.

Animal welfare science aims to objectively assess good or bad animal welfare in order to inform interventions, often focusing on win-wins that improve both human and animal lives. Based on scientific study many measures of welfare have been proposed, such as frequency of injury, ‘stress hormone’ (cortisol, corticosterone) levels in the blood, rates of negative behaviours like stereotypes (repeated, non-functional, often harmful behaviours) and conflict, or the occurrence of positive behaviours like foraging and grooming. These measures are used in a variety of ways: they inform new animal welfare laws; they feed into further scientific study; and they are used as indicators of good and bad welfare in assessment frameworks, for use in monitoring, comparison and marketing.

The Anthropocene is the proposed (and, so far, unofficial) name for a new and current geological epoch distinguished by humanity’s significant impacts on the planet’s physical, chemical and biological systems, including climate and ecosystems. The exact start date and definition of the Anthropocene remain debated.

Anthropocentrism literally means human-centred. It refers to a philosophy and worldview that bases moral worth on the capacity for analytic thought and judgement, and therefore sees humans as separate from and distinctive to the rest of the natural world. In some cases, this thinking is associated with the perception that nature only has value in the extent to which it can be exploited to meet human needs. It is often suggested that capitalism and western liberal democracy are informed by an anthropocentric worldview, and some people blame anthropocentrism for climate and environmental crises and the depletion of natural resources.

Aquaculture refers to the breeding, rearing and harvesting of animals and plants in aquatic environments.

An aquifer is an underground layer of rock, sand, gravel or earth that contains water or allows water to pass through it. Aquifers normally contain fresh water and are in many regions an important source of water for drinking, agriculture and other human activities.

Arable crops are those such as wheat and barley, which require good soil quality and a favourable climate to grow, and land amenable to the use of ploughing and harvesting machinery. Arable land is by definition land used to grow arable crops, in contrast to land used for fruit and vegetable crops and for pasture used to feed grazing animals.

Arthropods are invertebrate animals such as a spiders, shrimp or beetles that have an exoskeleton, a segmented body and paired jointed appendages (paired wings, legs or antennae).

Back breeding is an approach to livestock breeding and part of a family of de-extinction practices. In back-breeding programs, specimens, for example of certain domestic cattle breeds, are selected for breeding based on traits they are thought to share with an extinct ancestor species. This approach differs from conventional livestock breeding in that it tends to use other breeds and selects for a wider range of traits other than, say, meat or dairy yield. Sometimes, back-breeding projects deliberately avoid traits (such as aggressiveness) even when these are thought to have been present in the extinct species. Depending on when the species went extinct, it can be difficult to trace back its characteristics. Back breeding initiatives tend to rely on a combination of excavations and historical descriptions or depictions (cave drawings or paintings) of the species concerned. Sometimes these projects are based on idealised understandings of the species and do not consider the variety of traits that may have been present among different individuals.

Big food is generally used as a term of criticism, to refer to the most powerful global food industry players. Most commonly it denotes large companies from the food manufacturing, processing and retailing sectors, but can also be used to refer to large agricultural producers as well as companies that provide agricultural inputs such as seeds, fertilisers and pesticides.

Nutrient bioavailability is defined as the fraction of a nutrient in a food that is absorbed and utilised (has an active effect). Essentially, the more bioavailable a nutrient, the more easily it is absorbed and utilised by the body.

Biodiversity refers in the broadest sense to the variety and variability of living organisms in a particular area, or on earth in general. More specifically, the concept is used to denote different aspects of the variety and variability of life, e.g. the number of species in an area (species richness) or the size of species’ populations (species abundance). Biodiversity is measured in different ways and at various scales from the genetic through to the landscape level.

Biodiversity conservation refers to all human activity aimed at the preservation of both the variety and variability of living organisms in a particular area of concern, or on earth in general. People value different aspects of biodiversity in different ways, and can have different priorities in biodiversity conservation e.g. to protect an endemic species or a species that supports an ecological process important to human wellbeing such as pollination.

Biodynamic agriculture is a form of agriculture rooted in the ideas of German philosopher Rudolf Steiner, promoting holistic approaches to farm management, and the use of ecological methods rather than chemical inputs. Its on-farm practices overlap significantly with organic methods. However biodynamic practitioners also emphasise spiritual and mystical elements of human/nature relationships and many use astronomical calendars to guide sowing and harvesting, and fermented herbal remedies to promote plant and soil health and healing. 

Biological nitrogen fixation is the process through which atmospheric nitrogen (N₂) is converted into ammonia (NH₃) or related nitrogenous compounds by bacteria. BNF includes both the fixation of these compounds by bacteria that are present in the soil and by bacteria that live in the root nodules of legumes and certain other plant and tree species. The latter form of BNF is a symbiotic process: the bacteria provide the plant or tree with nitrogen compounds while the plant or tree provides the bacteria with carbohydrates. Nitrogen-fixating plant and tree species are often able to live on relatively poor soils with little need for additional manure or synthetic nitrogen fertiliser. Increased reliance on BNF as opposed to fertilisers is often considered to be an important aspect of a more sustainable food system.

Biomass refers to dry weight of plant-based material that has been harvested or is available on an area of land. Typically, it refers to the use of plants not for food or fibre, but rather for (bio)energy.

Biotechnology is defined by the United Nations as “any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use”. Applied to agriculture, biotechnology involves controversial as well as uncontroversial practices. Examples of biotechnology are the genetic engineering of crops (GMOs), conventional cross-breeding, breeding based on individual plants’ and animals’ genetic traits (molecular marking), cloning animals, and the production of new vaccines using microbiological methods.

C3 plants are those whose method of photosynthesis is adapted to cooler and wetter climates. They represent the majority of plants globally and include rice, soybean, and wheat. C3 plants are less efficient at creating energy for growth than C4 type plants in hot and dry climates.

C4 plants are those whose method of photosynthesis is adapted to hotter and dryer climates. They represent only a small fraction of plants globally. Examples include some grasses, maize, sugar cane, millet, and sorghum. In hot and dry climates, it is more efficient at creating energy for growth than C3 plants.

Carbon dioxide equivalent (CO₂.eq) is a measure used to compare and combine the warming effect of emissions from different greenhouse gases, using single measure of impact. This is done on the basis of a conversion factor known as the Global Warming Potential (GWP), which is the ratio of the total energy trapped by a unit of greenhouse gas (e.g. a tonne of methane) over a specific period of time (normally 100 years), to that trapped by carbon dioxide over the same time period.

Carbon intensity refers to the amount of carbon emissions that are produced to achieve a specific outcome. For example, the carbon intensity of electricity is the emission produced per unit of electricity supply.

A carbon price is a cost that must be paid for the right to produce a unit of carbon pollution. This may take the form of a carbon tax on pollution or an obligation to buy permits from a carbon market. In either case, the goal is to promote investment by polluters to reduce emissions of carbon dioxide and other greenhouse gases.

Carbon sequestration is any process by which carbon dioxide is removed from the atmosphere and stored elsewhere, whether by biological or technological means. There are two main types of carbon sequestration, terrestrial (carbon plants and soils), and geologic (carbon stored in rock formations) . One classic example of carbon sequestration is reforestation.

A carbon sink is a reservoir (natural or artificial) which accumulates and stores carbon over time. The process of removing carbon dioxide from the atmosphere by increasing the sink capacity of the reservoir (which could be a soil) is called carbon sequestration

Carbon stock refers to the amount of carbon stored in plants, soils, and ecosystems.

Carrying capacity, in ecology, refers to the maximum population of a species that can be sustained by a particular environment. The concept can also be applied to people, for example in attempts to calculate how many humans the earth can sustain indefinitely.

Cellular agriculture refers to the production of agricultural products (foods or food ingredients as well as fuel or fibre) using cell cultures. Cell-based meat is a well-known example of cellular agriculture.

Choice architecture refers to the design of which choices are made available or not to people in a given context, and how these different choices are presented to them. In any context, there is always a choice architecture affecting decision making, whether deliberately designed or not. For example people's purchasing decisions in a shop are dictated by the products available to buy in a grocery shop, their price, their presentation and visibility, the extent to which they are advertised and promoted and so forth: these collectively constitute the choice architecture.

Climate smart agriculture (CSA) was first introduced by the FAO in 2010 as an integrated approach geared at reorienting and redesigning agricultural systems to address and build resilience to climate change, and is often discussed in the context of low-income countries. CSA involves three interconnected elements: increasing agricultural productivity and incomes; adapting and building resilience to climate change; and the mitigation of greenhouse gas emissions. It aims to identify context specific agricultural strategies supporting these elements and guide coordinated actions among stakeholders (e.g. farmers, researchers, private sector, civil society and policy makers) from the farm to the global level. CSA is criticised for justifying nearly any form of agriculture (thereby ‘greenwashing’ unsustainable practices) and for failing to address enduring inequalities in food production and distribution. CSA is closely related to the concepts of sustainable intensification and ecological intensification but differs from them in its strong focus on planning and implementation for climate change adaptation and mitigation, and less on reducing environmental impacts beyond emissions.

A cohort study, commonly used in medical and nutritional epidemiology, is a longitudinal study that samples a cohort (a group of people that is defined by having experienced the same event, e.g. birth or graduation, in a selected time period) and follows it over time to investigate people’s exposure to certain factors (e.g. the consumption of certain foods) and the occurrence of particular health outcomes. For example, a cohort study may measure the dietary patterns over time of a group of people who were born between 1960 and 1970 to find out which dietary patterns are associated with the development of diabetes or particular cancers. There are two types of cohort studies. Prospective studies follow a cohort of people who differ by certain factors (e.g. smokers and non-smokers) to study which medical conditions appear in what part of the cohort (e.g. after 20 years more smokers than non-smokers have developed lung cancer). Retrospective studies study a cohort after a medical condition (e.g. lung cancer) has occurred in a part of the group to trace back which factors (e.g. smoking) may have contributed to this.

A cold chain is a supply chain or part of a supply chain where products and raw materials are stored or transported at low temperatures (either frozen or refrigerated at a temperature generally lower than 8°C).

Colorectal cancers are those of the bowel and colon.

A companion crop is a plant grown in close proximity to another crop plant in order to provide some benefit. Such benefits include legumes grown to provide nitrogen fixation and lower the need for synthetic nitrogen inputs, densely growing undercrops that do not compete with the crop but cover the soil and prevent weed growth, plants with insect-repelling properties to reduce pests, flowering plants which attract pollinators, and others. By replacing other, artificial interventions to achieve these goals, companion planting can be considered an example of a 'nature-based solution'. Companion crops might themselves also be food crops, or be grown solely for these benefits to the primary crop. Companion planting is a form of polyculture, and is typical of permaculture and agroecological growing.

See companion crop.

A confounding factor is a factor that influences the relationship between variables that are investigated. In dietary research, for example, a lack of physical exercise may potentially confound the association between the consumption of soda beverages and overweight: when those who drink the most soda beverages are generally more overweight, but also exercise less, the association between the consumption of soda beverages and overweight may be caused partly or entirely by a lack of exercise. Other common confounding factors include age, gender, whether people smoke or drink alcohol, occupation, educational attainment, or income. Confounding factors are a potential bias in statistical research and may lead to over- or under-estimating the relationship between variables. While theoretically their number can be infinite, statistical research often accounts for a set of known potential confounding factors.

Often described as a mission-driven discipline, conservation biology is a field of study concerned with the protection and maintenance of the earth’s biodiversity. Research in conservation biology draws on other disciplines including ecology, biology and the social sciences and humanities.

Conservation grazing is the use of grazing livestock to maintain or increase the biodiversity of natural pastures and other habitats.

The concept of the ‘corporate food regime’ was developed by political economist Phillip McMichael, in his work identifying different historical phases in the political economy of food and agriculture. He characterises the period from the late 1980s onwards as the ‘corporate food regime’ due to the increasingly prominent role played by large transnational corporations in all aspects of food provisioning, including through their influence on  market prices and the establishment of new regulations and trade policies. The idea is widely used by academics, particularly proponents of food sovereignty, to critically refer to the various actors and processes that facilitate the dominance of an export-led global food system.

Cost-benefit analysis looks to inform policy decisions by calculating all related costs and benefits associated with a given decision. For example, a government wanting to reduce meat consumption, could propose various policy options including banning meat advertising, taxing meat products, or subsidising the production of alternative protein. A cost-benefit analysis would estimate the costs and benefits of each option by using estimated economic values for any social and environmental benefits (like potential reductions in greenhouse gas emission and diet-related hospital admissions). The results of this cost-benefit analysis could then be used to inform policy. The process of cost-benefit analysis often involves discounting when estimating the benefits of a policy decision, because whilst costs are often upfront, any benefits tend to arise in the future. Cost-benefit analysis and discounting are both important approaches used in the creation of nature markets that place an economic value on the environment.

Cover crops are crops that are grown with the purpose of protecting or improving the soil, rather than for harvest. Cover cropping can prevent soil erosion, improve soil fertility and quality, and help prevent pests and diseases. This practice can reduce the need for chemical inputs and is commonly associated with agroecology, regenerative agriculture and organic farming.

Crop rotation is the practice of growing different types of crops in sequence across the same area of land. It is designed to optimize nutrients in the soil, improve soil health, and counter pressure from pests and weeds. This practice can reduce the need for chemical inputs and is commonly associated with agroecology, regenerative agriculture and organic farming.

Crop-livestock integration refers to the practice of combining the cultivation of one or more crop with at least one type of livestock. This integration is designed to reduce reliance on external inputs, as the crops provide feed for the animals, and the animal manure provides nutrients that foster crop production. Integrated crop-livestock farming is associated with agroecology, regenerative agriculture and organic farming.

De-extinction refers to the use of back breeding, cloning or genetic engineering to bring an extinct species ‘back to life’ or develop a species that is similar to it in terms of, for example, appearance and behaviour. The ambition of de-extinction initiatives is often for these species to be reintroduced and for them to contribute to the rewilding of landscapes.

Decoupling refers to the idea of disconnecting the growth of gross domestic product (GDP) from increases in environmental impacts – climate change in particular. The term is sometimes used more broadly in relation to overall human well-being rather than GDP. The idea of decoupling is based on the understanding that economic growth often goes hand in hand with increases in environmental impacts. Advocates of decoupling think that advances in technology will provide ways of fostering economic growth without increasing the use of resources or the generation of environmental impacts, and without requiring radical shifts in aspirations as to what constitutes a ‘good’ standard of living. Decoupling can be used both in a relative sense (e.g. a lower ratio of environmental impacts versus GDP) and in an absolute sense (i.e. the overall amount of environmental impacts is reduced). Relative decoupling is sometimes criticised for being open ended and thereby failing to speak to the need of keeping production and consumption levels within environmental limits. In general, critics question whether decoupling (both relative and absolute) is feasible for diverse reasons: because of the possibility of rebound effects; because it is unlikely to be possible to separate the production of goods and services from resource use (and the impacts of this resource use) to the degree that is necessary; and because the growth-based economic paradigm on which faith in decoupling is based fails to challenge the potential insatiability of human demand – an insatiability which (it is argued) lies at the root of our environmental crisis.

Deforestation is the clearance of forest or standing trees from land as it is converted to non-forest use. Deforestation can include the conversion of forest land to ranches or other agricultural activities. Important drivers of deforestation are the use of land for agriculture, ranching, infrastructure, urban expansion, and mining. Deforestation is often defined in relation to a cut-off date – e.g. all forest land cleared after June 2008 could be considered to be deforestation. Deforestation is a particular form of land use change. The concept is not commonly used to refer to types of land use change where other areas that may contain native vegetation (e.g. hay, marshes, savannas) are converted.

Deforestation risk is a concept used by supply chain transparency initiatives such as Trase to express the amount of deforestation or clearance of native vegetation after a certain cut-off date that can be linked to a particular batch of soy or another commodity. The deforestation risk is calculated as the number of hectares that is cleared of native vegetation in a particular region per tonne of yield, and is assigned to a trader or country on the basis of the amount of product it sources from that specific region. If a buyer sources 500 t soy from a region that produces 1000 t and where 800 ha of deforestation can be linked to soy production, the buyer faces a deforestation risk of 400 hectares (50% of the total) in this region.

Degrowth is a movement that argues we need to reduce material production and consumption in richer countries in a planned and equitable way. The movement criticises the capitalist focus on ongoing economic growth and argues that we need to organise society in a way that prioritises social and ecological wellbeing.

Desertification refers to a process by which fertile land becomes desert; this can be due to deforestation, drought or inappropriate agriculture methods.

The term 'dietary survey' refers to a group of methods that are used to collect food consumption data to study the diets of individuals or groups. Common methods in dietary surveys are food frequency questionnaires, food diaries, and 24-hour recalls. These are often combined with the weighing and analysis of food to determine its nutritional properties. Dietary surveys are sometimes combined with other methods (e.g. the measurement of BMI or blood values) to study the relations between certain dietary patterns and health outcomes. National dietary surveys, conducted and commissioned by national and international health authorities, study national dietary patterns and are often an important input for the development of food policy.

Disability-Adjusted Life Years (DALYs) are a way of measuring the burden of ill health. One DALY can be thought of as one lost year of healthy life. Across a population, DALYs are calculated by adding together years of life during which illness is experienced, weighted according to the severity of the illness, and years of life lost to premature mortality.

Dumping refers to the practice of exporting products at a price lower than the normal price (e.g. the price in the domestic market of the exporter, or the price in the market of a third country), in order to increase market share and drive out competition. It is a highly controversial practice as it tends to support farmers in rich countries at the expense of producers and consumers in low-income countries. Although it is legal under World Trade Organisation rules, it has been heavily criticised, particularly by the food sovereignty movement, for undermining domestic production and food security in the global South, and marginalising smallholder farmers in the global economy.

Eco-imperialism has been defined in various ways but is often used to refer to a situation where actors (e.g. people, communities, organisations or governments) that are perceived as powerful impose their ecological rationalities and actions, objectives or policies on other actors. A historical example of eco-imperialism can be seen in the development of national parks in the Americas by Western colonisers who (in many cases violently) expelled indigenous communities from the land.

With roots in the social sciences and heterodox economics, ecological economists appreciate the economic value of nature but argue that it also has many highly subjective social and philosophical values. They see the market valuation of nature as an inherently political act that limits our ability to protect nature – only a democratic process of comprehensive social change can achieve this goal.

Ecological intensification is the principle of using the natural functionalities of an ecosystem to produce greater amounts of food, fibre, and fuel in sustainable ways. Underpinning EI is the idea that ecological functions (e.g. pollination and predator/prey relationships) can be integrated into agricultural practices, ideally leading to ‘agroecosystems’ that are sustained by natural processes and avoid many negative environmental impacts. Ecological intensification is closely related to the concepts of sustainable intensification and climate smart agriculture, but differs in its strong focus on the potential of enhancing ecological processes in food production.

An ecological niche describes the role an organism plays within a community (which here refers to all the different groups of species commonly found within a particular area). A particular species’ ecological niche encompasses all resources and conditions (both biotic and abiotic) required for a species to maintain a viable population and its interactions with other species (including competitors and predators). 

As an example, we might talk about the ecological niche occupied by large, grazing herbivores: they are able to digest widespread but energy-poor and cellulose-rich food; they move relatively large distances and substantially alter the distribution of plant species across these ranges, creating grasslands and retarding or preventing afforestation; they are predated only by the largest carnivores in their habitats. Such a niche exists in many ecosystems but can be occupied by different specific species (larger deer, cattle, buffalo, etc.).

All abiotic processes (processes related to non-living things such as warming from sunlight) and biotic processes (processes related to living things such as plant, animal and microbial activities) or combinations thereof that influence the state of an ecosystem.

Ecological restoration refers to the principle of restoring something, for example a landscape or an ecosystem, based on ecological principles, processes or methods. An example of this can be the restoration of an deforested area by allowing forest to re-emerge through various forest succession stages rather than planting a mixture of the plant species that used to be present before the area was deforested. Ecological restoration can take place as part of a rewilding strategy. Rewilding strategies, however, tend to come with more specific ideas about which species should be present or (re)introduced and a clear overall vision about particular processes in the ecosystem that should be encouraged.

Ecology is a field of science that studies the interactions and connections between plants and animals and their natural environment.

Ecomodernism is an environmental philosophy rooted in the belief that technological progress can allow humans to flourish while minimising our impacts on the environment, in particular by freeing up land for conservation by intensifying the production of food and other resources using technology. Ecomodernism as a movement encompasses a diversity of views, but perhaps the most coherent exposition of the ecomodernist philosophy is the Ecomodernist Manifesto of 2015. Read the full TABLE explainer What is ecomodernism? for a more detailed discussion of the movement and its ideas.

An ecosystem is a structural and functional unit in ecology that describes living organisms, their physical environment, and all their interrelationships in a particular unit space. Ecosystems consist of two main components. The biotic component consists of all animals, plants, and other living organisms. The abiotic component consists of all non-living aspects of the physical environment (climate, non-living components of soil, nutrient and light availability, etc.). The interactions between biotic and abiotic components of an ecosystem naturally maintain an equilibrium in the environment.

Ecosystem restoration refers to the process of restoring aspects of an ecosystem that have been lost through for example the reintroduction of species or management practices to regain lost landscape features. The restoration of an ecosystem can be an outcome of rewilding. Not all rewilding strategies, however, aim to restore (aspects of) ecosystems that have been lost. Some rewilding strategies are more future oriented.

Ecosystem services are the tangible and intangible benefits that are provided by ecosystems to humans, which both enable human life and that contribute to its quality. Ecosystem services include provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual, recreational, and cultural benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth.

Ecotoxicity refers to the toxicology of pollutants in the environment. The study of ecotoxicology includes consideration of the interaction of pollutants both with abiotic aspects of the environment - soil, air and water; and how they interact with living systems, at the level of cell, organ, and organism to communities and ecosystems.

Eddy covariance is a meteorological monitoring technique that can be used to measure the movement of different gases in situ. Applications include, for example, to measure the concentration of methane in the air near agricultural sources.

Endemic species is a plant or animal species that is unique to a specific geographic location, such as a country or an island. Usually the area where an endemic species live is isolated, making it difficult for the species to move to other areas. Endemic species are often uniquely adapted to the specific environment in which they live. Almost all endemic species are specialist species.

Enteric fermentation is a natural part of the digestive process of ruminant animals (e.g. cattle and sheep) where microbes decompose and ferment the food present in large rumen portion of the stomach. As a byproduct of this fermentation process, some bacteria species in the stomach produce methane.

With roots in neo-classical economics, environmental economists state that nature’s value lies in the ecosystem services it offers; and objective assessment can assign monetary value to these services. They argue that fully incorporating nature’s economic value into markets then leads to solutions that protect it. See also ecological economists.

Epidemiology is a scientific discipline that uses data mathematical tools to understand the patterns of disease found in human populations and changes therein. It seeks to explain exactly how these patterns are caused in order to identify ways to control and treat health problems.

Eutrophication refers to the buildup of nutrients in a body of water (e.g. nitrogen and phosphorus) to a level in excess of what would occur naturally and to which aquatic ecosystems are adapted. This can result in detrimental impacts on many aquatic plants and animals, as well as the rapid overgrowth of some plants and algae.

Extensive agriculture has no clearly bounded definition, but generally refers to production systems that use minimal inputs, are often lower yielding, and cover a large land-area in relation to animal numbers. An example of this is continuous grazing of entirely pasture fed livestock including sheep and cattle. The practice may be contrasted with intensive agriculture in debates around livestock production.

Externalities are side-effects of activities or economic transactions that affect people who did not take part in the activity or transaction. Externalities can be negative (for example second-hand smoke from cigarettes can make other people ill) or positive (for example vaccines can protect those who do not receive them, by reducing the spread of disease). Externalities are not usually reflected in the price of an economic transaction, because the costs are usually borne by third parties.

The Food and Agriculture Organisation (FAO) is a specialised agency of the United Nations. It is dedicated to leading international efforts to defeat hunger worldwide.

Farm-free production systems refer to systems that generate food or types of fuel or fibre that are conventionally produced by agricultural systems but which are not produced on a farm. An example of a farm-free production system is the production of cellular meat in a bioreactor. While advocates of farm-free production systems tend to point towards potentially radical reductions in agricultural land use to produce a certain amount of food (or other products), farm-free production systems can be based on the use of ingredients (such as corn starch or soy protein) that are derived from more land-intensive production systems.

Farmer field schools allow farmers to acquire skills and knowledge through participatory and hands-on learning. They are designed to facilitate experimentation and discussion amongst farmers and to encourage the uptake of more sustainable production practices. This approach is favoured by the UN FAO, and has long been an important feature of agroecology movements.

Feed conversion efficiency is a measure of how much feed is required to produce a certain amount of a desired output. Such outputs may be animal weight, the amount of milk or meat produced, or even nutritional value measured in calories or grams of protein. It is a metric used to compare animal breeds and species in terms of their ability to convert feed into food available for human consumption.

A feedlot, also known as a feed yard, is a system used in intensive meat production. The basic principle of the feedlot is to increase the amount of weight/fat gained by each animal as quickly and efficiently as possible. Animals are kept in confined quarters and are commonly fed a grain-based diet such that they fatten rapidly prior to slaughter. Feedlots are commonly used in large-scale, intensive ruminant (notably beef cattle) farming. They are primarily associated with the beef industry in the US, Canada, and Australia but are rapidly spreading elsewhere (especially in South American countries like Brazil).

Food additives, including colourants, flavour enhancers, sweeteners, emulsifiers, and preservatives, are substances that are added to foods to preserve them or to enhance their taste and appearance. A food additive may have nutritional value but is not normally consumed as a food by itself. Generally not considered to be food additives are herbs, spices and substances such as micronutrients (for example iron or vitamin B12) that are added solely to improve a food’s nutritional qualities. Many food additives have a long history and are derived from food ingredients or non-food substances that have traditionally been used for processing foods (e.g. chalk or beetroot juice colourant). Others are produced using chemical synthesis (e.g. aspartame and synthetic vitamins). Some question the health impacts of certain additives from this latter group. Many national and international health authorities regulate additives by banning their use and by defining intake limits.

An alternative term to food desert, promoted by a growing number of activists, that places a greater focus on systemic historical and structural issues associated with race and socio-economic status that limit peoples’ access to affordable, nutritious, and healthy food. Food apartheid can be seen as a more descriptive term that considers how racial, economic, and structural issues within the food system intentionally deny certain communities, particularly Black and ethnic-minorities, access to nutritious foods. The term and associated movement are credited to Karen Washington a Black urban gardening activist from the Bronx (see article here).

The food chain is a hierarchical network constituted by the succession of organisms that eat other organisms and may, in turn, be eaten themselves. The position an organism occupies in a food chain is indicated by its trophic level. Plants, algae, and phytoplankton constitute the lowest trophic level, whereas predators and carnivores constitute the highest trophic levels. Many humans consume food from different trophic levels, while those following vegetarian and vegan diets consume all or most of their food from the primary trophic level.

A food desert is an area where peoples’ access to affordable, nutritious, and healthy food (particularly fresh fruits and vegetables) is limited or non-existent, primarily due to barriers to purchasing fresh food such as lack of affordable local stores and markets or lack of accessible transportation options to reach other purchasing options. The presence of food deserts is often correlated with the socio-economic status of residents – they are prevalent in ethnic minority, low-income communities lacking adequate access to transportation. In contrast, an area with greater access to affordable, nutritious, and healthy food may be described as a food oasis. Food deserts are often associated with urban areas and some activists and experts assert that food deserts are a symptom of systemic discrimination; see Food apartheid.

A food frequency questionnaire is a dietary assessment tool commonly used in nutrition research that consists of a questionnaire in which participants are asked to answer questions relating to the frequency with which they consumed certain foods and drinks during a selected time period, e.g. a week, month or year. Food frequency questionnaires can be long or short and interviewer- or self-administered. They are commonly used to investigate the dietary patterns of large populations, and unlike 24-hour recalls, they can measure the consumption of foods that are eaten incidentally or occasionally. Limitations of food frequency questionnaires include their reliance on participants’ ability to accurately recall the foods and drinks they have consumed over a relatively long period, and the possibility of social desirability bias (e.g. people may over-report their consumption of foods they think are healthy or sustainable).

Food justice is defined as the right of communities everywhere to produce, process, distribute, access, and eat good food regardless of race, class, gender, ethnicity, citizenship, ability, religion, or community. The food justice movement emerged in the 1990s in the US, primarily amongst Black and ethnic-minority urban communities, to highlight in particular the racialised nature of inequalities within the food system.

Food preservation encompasses the processes and techniques that are used to prevent food from spoiling, including canning, pickling, salting, drying, smoking, chilling, fermenting, pasteurising, and the addition of chemicals such as sodium benzoate (which dissolves in food as an acid). These measures inhibit the growth and survival of microorganisms that spoil food. Food preservation can be understood as a form of food processing.

Food processing, defined by stakeholders in many different ways, broadly refers to modifications made to raw food ingredients after they have been gathered or harvested and before they are consumed or prepared for consumption in a kitchen. Examples of food processing include the pickling of vegetables, smoking or mincing of meat, pasteurisation of milk, milling of wheat, and the hydrogenation of oils. By this definition, most foods are processed in some way (e.g. to improve their taste, extend their shelf-life, make them edible or increase their nutritional value), but there are growing concerns over the health impacts of industrially processed foods.

Food security is an idealised state or goal where all people, at all times, have physical, social and economic access to sufficient, safe, nutritious, and culturally appropriate food to meet their dietary needs and food preferences for an active and healthy life.

Food sovereignty is a political movement that emphasises the rights of food producers, distributors and consumers to have control over the food system, as opposed to corporations and market institutions. It has been defined as the right of peoples to healthy and culturally appropriate food produced through ecologically sound and sustainable methods, and their right to define their own food and agriculture systems.

Forest degradation is the long-term reduction in the overall capacity of a forest to produce or provide benefits, such as carbon storage, biodiversity, wood, and other products due to environmental and anthropogenic alterations.

Fortification refers to the addition of micronutrients to foods to improve their nutritional quality. For example, micronutrients such as iron, zinc, or vitamins A and B may be added to rice or white bread. Fortification is seen as a way of improving the nutritional status of a population.

Fortress conservation is an approach to conservation that is based on the belief that goals for nature conservation are best achieved by the establishment of (large) nature reserves that are (largely) inaccessible to humans. Fortress conservation is controversial both for its assumption that the protection of biodiversity would be best served by creating isolated conservation areas and because it can go hand-in-hand with – and has historically done so – harms to rural and indigenous communities (e.g. displacements or even ethnic cleansing) who inhabit areas that are or were turned into fortress conservation projects.

An economic system in which the prices of goods and services are determined by supply and demand, and there is little to no intervention from government or external authorities. The term is tightly linked to the concepts of market liberalisation and neoliberalism.

When talking about soil, friability describes the ability of a mass of soil to disintegrate, break apart, or crumble into smaller fragments under applied stress. Essentially a friable soil has a crumbly texture.

A functional unit refers to the product, service, or system whose impacts are calculated by a life-cycle assessment (LCA). Common examples of food-related functional units are 1 kg of beef, 100 calories of food, or 1 ha of land. The choice of functional unit influences an LCA’s results and care is needed when comparing the results of LCAs with different functional units. The functional unit is defined in the first phase of a life-cycle assessment study – that of goal and scope definition.

A generalist species is a plant or animal species that is able to thrive in a large variety of environmental conditions, or that can live on a wide variety of foods. Members of the same generalist species can often be found at different parts of landscapes and in different regions of the world.

GHGs is an abbreviation for greenhouse gases. These include gases such as carbon dioxide, methane, and nitrous oxide, which affect outgoing radiation, leading to global warming.

Global warming potential (GWP) refers to quantifying the strengths of different greenhouse gas emissions relative to carbon dioxide (CO₂). Derived from estimating the total change in atmospheric energy balance resulting from a pulse emission of the gas, relative to CO₂, over a specified time-frame (typically 100 years).

Green manures are fast-growing plants sown to cover bare soil, smothering weeds, and preventing soil erosion. They are dug into the ground whilst still green to add organic matter to the soil, slowly release nutrients for following crops and improve soil structure. Legumes (such as clover), which can perform biological nitrogen fixation, are often used as green manures to add nitrogen to the soil for following crops.

The Green Revolution was an agricultural modernisation programme in the 1950s and 1960s that promoted the widespread adoption of fertilisers and pesticides, agricultural machinery and higher-yielding varieties of maize, wheat and rice around the world, particularly in Latin America and Southeast Asia. It was led by the US government along with the Rockefeller Foundation and the Mexican government, and was further promoted by development agencies, agronomists, and policy makers. Different reasons are attributed to its widespread promotion, including concerns about increasing food supplies to meet the demands of a growing global population, worries about rural unrest in the context of the Cold War, and a desire to expand farm input markets. The impacts of the Green Revolution are a topic of much debate. Proponents who seek a new 21st century Green Revolution highlight its role in increasing agricultural yields in Asia and Latin America; critics, on the other hand,emphasise that it did not effectively tackle hunger and malnutrition and that it resulted in environmental degradation, serious social inequalities and unhealthy dietary change. 

Greenwash or greenwashing describes when positive environmental claims are used misleadingly in public relations or advertising to divert attention from environmental impacts. It is often used in the context of identifying information hazards associated with particular environmental interventions or arguments. A low-impact intervention or an intervention that affects only one component of a larger system of impacts might be worth pursuing in the abstract, but have a net harmful effect by providing actors with excuses not to take more substantive action (or rhetorical distractions from their lack of more substantive action).

GWP* is an alternative application of Global Warming Potential to derive carbon dioxide equivalents (referred to as CO₂e* if using GWP*) that primarily relates the change in the rate of short-lived greenhouse gases (such as methane) to a fixed quantity of CO₂, rather than a direct equivalence between emissions of both short- and long-lived greenhouse gases, as is the case for conventional use of the 100-year Global Warming Potential.

Habitat fragmentation describes the breakup (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay.

Heathland is a shrubland habitat that is characterised by the presence of heather.

Hectare (ha) is a unit of land equal to 10,000 square meters or 2.4711 acres.

Broadly speaking, heterodox economics refers to economic theories and methodologies that differ from or directly contradict mainstream neo-classical economics. Heterodox economic approaches are used by ecological economists who seek a move away from policies based on conventional environmental economic thinking.

The Holocene is the current geological period and started about 11,700 years ago after a process of glacial retreat and a mass extinction of megafauna such as the sabre-toothed tiger, the mammoth and the woolly rhinoceros. The start of the Holocene roughly corresponds with the invention of agriculture and the start of a process of rapid growth and spread of the human species worldwide.

Holocene rewilding is a rewilding strategy that takes the early to late Holocene (after the emergence of agriculture and before the industrial revolution) as its historical baseline for ecosystems. Whereas Pleistocene rewilding is associated primarily with the reintroduction of large carnivores, Holocene rewilding emphasises the role of large herbivores such as (ancient) cattle and horse species in managing the landscape. Holocene rewilding revolves around the wood-pasture hypothesis by the Dutch conservation biologist Frans Vera, which states that after the last ice age, European lowlands will have developed into semi-open pastures dotted with large solitary trees and small patches of trees and shrubs, kept open by large herbivores. This hypothesis is contested.

Hydrogenation is a chemical reaction between a hydrogen molecule (H₂) and another molecule or element in the presence of a catalyst such as palladium, platinum or nickel. In the food industry, hydrogenation is often used to turn liquid oils into solid fats. The partial hydrogenation of oils is used to produces trans-fats. Hydrogenated fats and trans-fats are contested for their health impacts.

Hydroxyl (OH) radicals are highly reactive molecules responsible for the initial reaction leading to most methane destruction in the atmosphere, and also important for the removal of many other atmospheric pollutants. Radicals are molecules or atoms with an unpaired electron, often making them very reactive.

IGOs (intergovernmental organisations) are non-state organisations established through international law by treaty. Prominent examples include the United Nations and the World Health Organization. IGO is also sometimes used more loosely to describe NGOs whose scope is international, also called INGOs (international non-governmental organisations).

Industrial food manufacturing refers to the large-scale production of food products by processing companies using highly mechanised assembly lines and according to pre-defined specifications that guarantee the production of a product with a constant quality. Most of these foods are produced for the retail and consumer market.

Intensification refers to a process by which farming systems (for crops or livestock) are reorganised – often through the application of new technologies, economies of scale, and the use of additional inputs, such as nutrients, chemicals, energy and water – in order to produce more of a desired output (e.g. meat) while using less land, human labour, or capital. The result is that the costs of production for a given amount of food are reduced, thereby increasing profits through larger profits per unit of food, or by expanding total consumption through lower prices, enabling more people to buy more. Often, environmental impacts per unit of product are also reduced, but may be counterbalanced by increases in total production. The impacts of intensification processes on animal welfare, biodiversity, and other issues is also a widely held concern.

Intensive agriculture (IA) is often used synonymously with the terms industrial agriculture and conventional farming. IA is generally used to denote farming systems that use modern technologies and economies of scale to maximise yields relative to land use and production costs (e.g. costs of labour, technology, seeds, fertilisers, and pesticides). IA is associated with high use of chemical fertilisers, agrochemicals, and irrigation. This combination of agricultural technologies became common during the Green Revolution in the mid-20^th century and has long been criticized for its high social and environmental impacts.

Interstitial waters refers to water trapped in sediments or in pores (voids or spaces) in sedimentary rocks – rocks formed by the deposition and cementation of material, as opposed to rocks formed by volcanic processes.

An invasive species is a species that is considered non-native or alien to a given ecosystem and whose introduction has caused, or is likely to cause, significant changes to the ecosystem. Invasive species can be seen as a subgroup of non-native species with characteristics that make them spread easily within their host ecosystem. Their impacts on ecosystems are often perceived as negative and harmful. For example, invasive species are typically described as crowding out populations of native species or harming them in other ways such as through predation. Some conservationists are critical of categorising species as native, non-native and invasive species. They point out that species have always travelled from one ecosystem to the other, in many cases enabled by the travels of humans. Some species that are perceived to be invasive in one area can also be near extinction in places where they are considered to be ‘native’ to.

The Intergovernmental Panel on Climate Change (IPCC) is the international body for assessing the science related to climate change. It is administered by the United Nations with participation and decision making from 195 member states. The assessments that it produces provide the basis for government at all levels to create climate related policies.

The island biodiversity theory is a theory developed by North American conservation biologists in the 1960s that states that the richness of species on a given island is predicted by two factors: a) the size of the island and b) its distance from the mainland. The smaller and further from the mainland an island is, the less biodiverse it will be.

Iso-calorific is a term that means to hold the amount of calories in a diet constant, while changing other variables. It is used in research as a way to make meals with different compositions in terms of foods and nutrients, equivalent and comparable in terms of the energy that they provide.

Isotopic signature refers to the ratio of different isotopes. Isotopes are atoms that have a different number of protons and neutrons. For example, most carbon (C) has 6 protons and 6 neutrons, giving it an atomic weight of 12. This form of carbon is known as carbon-12 (or ¹²C). Another stable form of carbon exists with 6 protons and 7 neutrons, giving it a molecular weight of 13, hence it is known as carbon-13 (or ¹³C). Different sources of methane emissions can be composed of different proportions of ¹²C and ¹³C, with fossil fuel sources often containing relatively more ¹³C than biological sources.

Jevon’s paradox occurs when increased resource use efficiency (for example due to technological innovation) causes a rebound in consumption. That is, greater efficiency in the way a specific resource is used causes its cost to fall which then increases demand; subsequently the amount of that resource being used goes up.

A keystone species is a species that has a disproportionate influence on the functioning of an ecosystem relative to its numerical abundance and in comparison with other species such that its loss or (re)introduction in an ecosystem can affect the ecosystem’s overall functioning. Species such as the wolf, elephant or beaver are often considered to be keystone species but keystone species are not necessarily mammals. For example, woodpeckers or particular starfish species are sometimes included in this category.

Kwashiorkor is the name given to a syndrome often found in communities with poor access to food. It is particularly associated with children shortly after weaning. It is characterised by oedema (swelling), especially of the extremities, a distended abdomen, an enlarged, fatty liver, and changes to skin and hair colouration.

Although this cluster of symptoms had often been observed in young children and in food insecure communities throughout the historical record, it was only identified as a syndrome and named in the 1930s in two papers by Cicely Williams, a doctor working in the Colonial Medical Service on the Gold Coast (modern day Ghana). Williams later became the first head of the Maternal and Child Health division of the WHO, and was among many to support further investigation into kwashiorkor. By the 1950s it was widely believed both that kwashiorkor was caused by diets with sufficient calories but deficient in protein, and that it was the leading cause of child mortality in the world.

Later work has complicated both the epidemiology and medicine of kwashiorkor. By the early 1970s it was clear that in many communities, diseases of food insecurity in young children were more likely to present as marasmus (see Protein malnutrition and PEM) than as kwashiorkor—sometimes different presentations could be found in children eating the same diet. The idea that kwashiorkor was the leading cause of child mortality around the world was not supported by the evidence, although the claim is still sometimes made in the literature even now. It was also no longer clear that kwashiorkor was caused by specific protein deficiency, since it is rarely found without undernutrition (insufficient calories).

Even though the best treatment regimens involve gradually introducing more protein into the diet, there is still not complete agreement on the cause(s) of kwashiorkor. Poor diet, particularly a diet deficient in protein, is central, but many other factors have been argued to play a role, including recurrent gastroenteritis, fungal infections  and parasites. Nevertheless, the term is still often used in typologies of protein- energy malnutrition to refer to specific protein malnutrition (see Protein malnutrition and PEM).

La Via Campesina (LVC) is a transnational social movement, made up of 200 million people across 81 nations. It was formed in 1993 by peasants and smallholder farmers from around the world in response to the negative impacts of trade liberalisation and diminishing state support for small-scale agriculture. It has since grown to include landless people, rural women and youth, indigenous people, migrants and agricultural workers. LVC has played a key role in the food sovereignty movement, leading protests against global free trade agreements and promoting agroecology and smallholder farming. LVC has a decentralised structure, made up of multiple autonomous organisations, and prioritises inclusivity and democratic decision making.

Land sharing is the principle of integrating nature conservation approaches into agricultural production across a region. Its characteristics are that of low-yielding farmland with higher biodiversity, but with less land available for the sole purpose of nature conservation. Land sharing sits at one end of the two extremes of the land sparing-sharing continuum. It has in particular been criticised for leading to lower levels of biodiversity on a regional scale and for a tendency for generalist species to thrive at the expense of specialist or endemic species.

Land sparing is the principle of segregating land for nature conservation from land for food (or agricultural) production within a region. It consists of high-yielding farmland with relatively lower biodiversity, with the remaining land being spared for nature conservation. Land sparing sits at one end of the two extremes of the land sparing-sharing continuum. It has in particular been criticised for its (supposed) connection to environmentally unsustainable intensive agriculture and for undermining the food security of smallholder farmers and rural economies.

Land use is the purpose for which an area of land is used by humans: e.g. cropland, urban settlements, managed forests. Wild land, by contrast, is that not used by humans.

Any plant belonging to the family Fabaceae (commonly known as the pea or bean family), or the fruit or seed of such a plant. Many edible crops are legumes including peas, beans, soybeans, chickpeas, peanuts, and lentils. Edible legumes harvested for their dried seeds are also known as pulses. Some forage crops like clovers and alfalfa are also legumes.

Legumes are of further agricultural importance as the majority form root nodules containing symbiotic (mutualistic) nitrogen-fixing bacteria. Thus, they naturally add nitrogen to the soil and so play a key role in crop rotation and are often used as green manure (particularly clover). Other plants do form such mutualistic relationships with nitrogen-fixing bacteria, but on far smaller scale. Thus, in agricultural contexts, including legumes in rotations often replaces the role of mineral nitrogen fertiliser.

Life cycle, in the context of life-cycle assessment and carbon footprint analysis, refers to the entirety of phases a product or system passes through from its development, through to its use and, eventually, how it is managed as waste. A life cycle is generally understood to start at the growing and harvesting or mining of raw materials and to end when a product is disposed of as waste. While waste management is thought to be a part of a product’s life cycle, potential recycling is generally considered to be part of the life cycles of other, new products. For example, the life cycle of a loaf of bread may be thought to consist of the following phases: the growing and harvesting of corn and other ingredients (including pre-production of inputs such as fertilisers), their transport to a bakery, bread production, transport and retail, consumption and waste.

A livelihood is a person’s, household’s, or group of people’s means of making a living. It encompasses people’s capabilities, assets, income, and activities that are required for securing the necessities of life, such as food, water, medicine, shelter and clothing.

Livestock on leftovers is the term given to a theoretical model of a food system with a specific, limited role for livestock agriculture inspired by traditional uses of livestock as recyclers of food waste. Using this system, livestock animals would eat only human-inedible feedstuffs such as grass, food waste, waste biomass from biofuel production and other industrial by-products – thus recycling otherwise inedible biomass streams into the food system. This concept has been proposed as a way of minimising feed-food competition without eliminating animal agriculture altogether.

Macronutrients are fats, proteins, and carbohydrates (starch, fibre, sugar) that are needed for a wide range of bodily functions and processes.

Malnutrition refers to deficiencies, excesses, or imbalances in the energy, macronutrients, or micronutrients that a person obtains. This is either because their diet is lacking or because their body is not able to fully absorb the nutrients from the foods eaten, e.g. due to illness. Malnutrition is an umbrella term that includes overnutrition (an excess of food energy), undernutrition (a lack of food energy and macronutrients such as protein), and micronutrient deficiencies (insufficient micronutrients such as iron, vitamin A or iodine).

A mangrove is a salt tolerant tree or shrub that grows in tidal and coastal wetlands and swamps, typically in tropical and sub-tropical regions. They typically form mangrove forests and are globally important for biodiversity and carbon storage, and also for their role in coastal protection.

Marginal land is often defined as land that has little value for agricultural production because the difference between the costs of agricultural inputs (e.g. labour, machinery, agrochemicals) and the revenue that can be achieved from yields is small compared to  what can be achieved on other land. Marginal land is sometimes defined in contrast with arable land, where marginal land is understood to be land that is unsuitable for crop production but still could be used for grazing by livestock. While the agricultural value of marginal land can be low, both its existing and potential value for biodiversity conservation can be high.

Market liberalisation means that there is a lessening of government restrictions and regulations to the market, such that the market is primarily controlled through supply and demand.

A Mediterranean diet is an idealised dietary pattern that has commonalities with the diets traditional to many Mediterranean countries. It is a diet that is primarily based on vegetables, fruits, pulses, nuts, cereals, olive oil, and fish, with moderate consumption of dairy and low to moderate amounts of meat. Mediterranean type diets are considered to have health conferring benefits.

Microalgae are microscopic algae typically found in freshwater and marine ecosystems

Micronutrient deficiencies result from a diet lacking the essential vitamins and minerals that humans require in small amounts for proper growth, development, and bodily functioning. These include iodine, calcium, iron, zinc, and vitamins A, B, and C, among others. Micronutrient deficiencies are the cause of a range of diseases affecting physical and mental development, and can increase susceptibility to infectious diseases.

A micronutrient deficiency refers to not getting enough of one or more micronutrients, which can occur even if a person is receiving sufficient energy from their diet.

Micronutrients are minerals (e.g. iron) and organic compounds (e.g. vitamin A) found in food, which the body requires in very small amounts to produce substances such as enzymes and hormones. They are essential for proper growth, development and bodily functioning. Essential micronutrients are those that cannot be synthesised by the body and so must be obtained through diet.

See Zero-tillage farming.

Minimally processed food is a category of foods in the NOVA classification that have not been processed (e.g. fresh fruits and vegetables) or that have been modified only minimally by processes such as drying, roasting, boiling, freezing, and the removal of inedible parts. Advocates of NOVA understand minimally processed foods to be processed to extend their lifetime, enable their storage, make them easier to prepare, or to increase the number of ways they can be consumed. Examples include fresh meat and vegetables, whole wheat grains, wholemeal flour, ground coffee and pasteurised milk.

Mob grazing is a specific form of rotational grazing in which stocking density is particularly high but recovery time is particularly long. This is argued to have benefits for soil health and carbon sequestration, and as such forms part of regenerative grazing for some practitioners.

Monoculture agriculture consists of cultivating only a single type of crop on a specific field/piece of land. Often the preferred method of cultivation in intensive agriculture. Contrast with polyculture which involves cultivating two or more crops on the same piece of land.

A monogastric is an animal with a single-compartmented stomach. Examples of monogastrics include humans, poultry, pigs, horses, rabbits, dogs and cats. Most monogastrics are generally unable to digest much cellulose food materials such as grasses. Herbivores with a monogastric digestion system (e.g. horses and rabbits) are able to digest cellulose in their diets through microbes in their gut, but they extract less energy from these foods than do ruminants. A major proportion of the feed given to monogastrics reared in intensive systems comprises human edible grains and soybeans.

The multiple burdens of malnutrition refers to the simultaneous presence of more than one form of malnutrition (e.g. undernutrition and obesity) in an individual, household, or population.

Mycelium (often used as a mass noun, but also with plural mycelia) is the root-like part of a fungus, forming complex branching structures that spread through the growing medium, often soil. Mycelium networks describe these branching structures, often those of multiple individual fungi; they are able to carry electrical signals, transport water and nutrients, and absorb from and secrete nutrients into the growing medium. Mycelium networks perform various essential functions in ecosystems such as contributing to soil organic carbon, providing a food source for invertebrates, facilitating nutrient absorption by plant roots and facilitating decomposition.

A symbiotic relationship between a fungus and a plant’s root system (its rhizosphere). The plant supplies the fungus with sugars produced during photosynthesis. In exchange, the fungus provides the plant with water and mineral nutrients (such as phosphorous), with the fungus essentially acting to increase the root system’s absorptive area.

A native species is a species that is considered indigenous to a given ecosystem or region. A species is typically perceived to be a native species when it has been present in the ecosystem or region for a long time. This can be anything from a few centuries up to several millennia. Which species are seen as native or non-native depends on the historical baseline one adopts and is to some extent open for interpretation and debate.

Natural capital, also known as environmental assets, refers to stocks of natural features that provide flows of benefits through ecosystem services to humans. It has been suggested that natural capital accounts can be used to assess the state and economic value of nature (ecosystem services) in a manner comparable to assessing economic growth using GDP.

Nature markets involve converting ecosystem services into tradable commodities which are bought by others mainly to offset the damage to ecosystems they are causing elsewhere, either on a voluntary or regulated basis. For example, companies or individuals may buy biodiversity credits that indicate a defined improvement in biodiversity to offset or neutralise an equal reduction in biodiversity they have caused elsewhere.

Nature- based solutions are actions to address societal challenges through the protection, sustainable management and restoration of ecosystems, benefiting both biodiversity and human well-being.

Neo-classical economics, also known as mainstream economics, emerged at the end of the 19^th century and dominates economic research and teaching around the world. Its focus is on the mathematical modelling of markets on the basis that they tend towards an equilibrium that maximises human welfare. It forms the basis of environmental economics and may be used by proponents of ecomodernism.

Neoliberalism is an ideology and a political and economic policy model that emphasises the importance of freedom from state intervention, the privatisation of public goods, and the primacy of economic growth and free market competition. Neoliberal policies were championed in the 1980s by US President Ronald Reagan and UK Prime Minister Margaret Thatcher – these policies included cuts to state spending and efforts to promote economic growth by privatising public services and deregulating the corporate sector. Neoliberal thinking has since gained traction amongst many national and global policy makers, and in the 1980s and 1990s led by the World Bank and International Monetary Fund to promote economic restructuring in countries around the world. More recently however, neoliberalism has received various levels of criticism. The 2008 financial crisis for example has prompted many economists and policymakers to call for greater government regulation of the financial and banking sectors. Although neoliberalism is recognised for increasing the wealth of certain portions of the world’s population, it has also been responsible for widening socio-economic inequalities and worsening climate and environmental crises. Debates about the value of economic growth and the ability of markets to efficiently and fairly allocate resources are therefore ongoing.

NGO (non-governmental organisation) is a loose term prototypically describing non-profit organisations that seek to influence public policy or discourse but are not part of a government. NGO is also sometimes used to include industry trade organisations and other private sector lobbying groups.

Nitrogen fixation is the process through which atmospheric nitrogen (N₂) is converted into ammonia (NH₃) or related nitrogenous compounds that, when present in the soil, can be utilised by plants. Plants are unable to utilise atmospheric nitrogen (N­₂) for plant growth because it is a relatively unreactive gas. There are two main processes through which nitrogen fixation occurs in the food system: artificial nitrogen fixation through the Haber-Bosch process – the process underlying the production of synthetic fertiliser – and biological nitrogen fixation (BNF) through bacteria in the soil and roots of particular plant and tree species such as legumes.

Non-communicable diseases are diseases which are not passed from person to person. They are often long lasting and generally progress slowly. Examples include cardiovascular diseases, cancer, chronic respiratory diseases and diabetes. Unhealthy diets are one of the major risk factors for non-communicable diseases.

The NOVA classification is a system of food classification created by a team of nutrition and health researchers at the University of São Paulo led by Carlos Monteiro. NOVA categorises food products by the ‘extent’ and ‘purpose’ of food processing on the grounds that today this is the main determinant of a food’s nutritional and environmental characteristics. NOVA has four categories: minimally processed food; processed culinary ingredients; processed foods; and ultra-processed foods. Introduced as a framework to measure the impacts of processed foods on human health, NOVA has also been promoted as an alternative to traditional government-approved dietary guidance such as the US MyPlate, the UK Eatwell plate or the Chinese Food Pagoda. While criticised, NOVA is increasingly used as a framework in nutrition science, especially in nutritional epidemiology. The dietary guidelines of Brazil (2014), Uruguay (2016), Ecuador (2018) and Peru (2019) and some reports from the PAHO-WHO have drawn upon the NOVA classification while the French (2019) dietary recommendations advise to reduce the consumption of ‘ultra-transformed’ foods.

Novel ecosystems are ecosystems that as a result of human influences have changed to the extent that the biotic elements (living things such as animals, plants or bacteria) and abiotic elements (non-living things such as water, rocks and air) are almost entirely different from what they have been in a historical state of the ecosystem. Novel ecosystems are defined relative to a past state of the ecosystem and the role humans have had in changing it. While this means that what does and does not count as a novel ecosystem is context dependent and subject to interpretation, the concept is generally used to refer to ecosystems that have experienced substantial human-induced changes in recent history (say the past two centuries). Examples of ecosystems that are often considered as ‘novel’ are deforested primary forests and areas that have a very different species composition due to the introduction and spread of non-native species resulting from human activity such as intercontinental trade.

Nudge approaches are the specific application of nudge theory, whereby the physical or informational environment in which decision making takes place is purposefully changed in order to affect behaviour. One example is using smaller plates to subtly limit overall food consumption in canteens.

Nudge theory is a concept in behavioural science, economics, and political science which tries to achieve non-forced compliance with desired behaviours (e.g. policies). It does this through the adjustment of messaging and the context in which decisions are made, in ways that have been found to predictably affect the motives, incentives, and decision making of individuals and groups of people.

Nutrient profiling is the classifying or ranking of foods according to their nutritional composition for reasons related to preventing disease and promoting health. Algorithms for this process are known as nutrient profile models or nutrient density indices. These vary in detail, most consider each item of food in isolation, but some account for the dietary context within which a food is eaten and other measures such as the carbon footprint.

Nutritional epidemiology is a sub-branch of epidemiology. This field of study focuses on the distribution and determinants of diseases and other medical conditions in a population. Nutritional epidemiology studies the relationships between dietary patterns, nutrient intake and their impacts upon public health. Common methods in nutritional epidemiology include dietary surveys and cohort studies, by which statistical associations between (say) food consumption and medical conditions such as cancer or obesity are studied.

Nutritionism, coined by the Australian academic Gyorgy Scrinis and popularised by the US journalist and food writer Michael Pollan, is a term used to describe and critique the dominant assumption of much nutrition science research – and often of mainstream dietary recommendations – that it is possible to understand the health implications of individual food products as well as dietary patterns in terms of their micro and macronutrient profiles. From this nutritionist perspective, foods are primarily viewed as interchangeable vehicles for the delivery of specific and isolated nutrients. Criticising ‘Big Food’ and the food products it provides, users of the concept tend to highlight the role of food in social and cultural life and argue that healthy dietary patterns mostly consist of home-made meals and dishes that are largely based on unprocessed food ingredients. Gyorgy Scrinis also argues that nutritionism has contributed to the food industry’s use of reformulation and nutrient fortification, which are aimed at improving a food’s nutrient profile.

Organic farming is an approach to farming in which synthetic chemical insecticides and herbicides and inorganic fertilisers are excluded. Underpinning organic farming is the idea that farming should rely on ecological processes, biodiversity, and cycles adapted to local conditions, rather than the use of inputs with adverse effects (e.g. agrochemicals such as pesticides and synthetic fertilisers).

Organic certification is protected by law, and certification bodies (e.g. the Soil Association in the United Kingdom) specify the practices, methods of pest control, soil amendments, and so forth that are permissible if products are to achieve organic certification. In the UK, for example, food can only be labelled as 'organic' if production rules are met; at least 95% of the agricultural ingredients are organic; and the product, its labels and suppliers are certified by a Defra-approved organic control body.

Overnutrition generally refers to excessive intake of energy and sometimes to the excessive intake of a particular macronutrient or micronutrient. Overnutrition in terms of energy often results in being overweight or obese.

Ozone is a molecule consisting of three oxygen atoms (chemical formula O₃; ‘trioxygen’). In the upper atmosphere (‘stratosphere’) ozone plays an important role in absorbing ultraviolet radiation from the sun, but is also a greenhouse gas, and at the surface has negative impacts on human health and plant growth. Ozone is also one of the by-products from atmospheric methane oxidation.

Ozone layer depletion is a decline in the level of ozone gas (O₃) present in the earth's stratosphere, owing to its breakdown into oxygen (O₂). This breakdown can be affected by natural processes, but is known to have been accelerated by the release of man-made chemicals, such as refrigerant gases. The ozone layer acts to reduce the amount of light at ultra-violet wavelengths reaching the earth's surface; wavelengths that can have harmful impacts on humans, including skin cancer.

PAHO-WHO is the abbreviation for the Pan American Health Organisation of the World Health Organisation.

A pandemic is the widespread occurrence (i.e. global or at multiple continents) of a disease during a particular period. Historically, many pandemics have involved infectious diseases that have been spread by viruses such as cholera and flu. Pandemics, however, can both be caused by communicable and non-communicable diseases.

Passive rewilding refers to the spontaneous rewilding of ecosystems when land is left to its own devices. It can be applied intentionally, but the concept also includes cases when (agricultural) land is abandoned. Arguably, as a result of farmland abandonment in Eastern Europe and some other world regions, unintentional passive rewilding currently covers far more land than do other forms of rewilding. Passive rewilding involves no or very little human intervention and does not specify an explicitly desired historical baseline scenario to which the landscape should revert, or include deliberate reintroductions of keystone species.

Pastoralism describes a form of animal husbandry and subsistence that involves raising livestock (e.g., cattle, goats, sheep, reindeer) in large, open, grassland environments (pastures). It is historically associated with a nomadic lifestyle in which people move with their herds as the seasons change.

Land covered with grass and other low plants suitable for grazing animals, especially cattle or sheep.

Permaculture is a landscape and settlement design movement that focuses on learning from observation of nature and ecosystems, systems thinking, and taking a long-term perspective. In the context of agriculture and horticulture, permaculture promotes the creation of food-producing ecosystems that require minimal ongoing human intervention. This often entails the use of perennials instead of annuals, minimising chemical inputs, the use of polycultures over monocultures, minimising soil disturbance, incorporating livestock and crops into the same system, agroforestry systems, and compost production. Permaculture shares some principles with and is related to various other 'natural' farming movements including agroecology, organic farming and regenerative farming.

Photochemical smog is observed as a haze in the atmosphere, typically near to cities. It is created through the action of sunlight on pollutants (nitrogen oxides and volatile organic compounds) emitted by automobiles and other industrial sources, which creates other pollutants harmful to health, such as ozone.

The planetary boundaries concept refers to the idea that humans are substantially altering natural systems, and that beyond a certain level of change this may become irreversible and self sustaining. The potential result is a planet with environmental conditions that differ substantially from those in which human civilisation developed and to which many species and ecosystems are adapted. Planetary boundaries have so far been proposed for climate change, biodiversity loss, biogeochemical cycles, ocean acidification, land use, freshwater, and ozone depletion.

The geological period that lasted from roughly 2.5 million years ago until about 11,700 years ago. The Pleistocene ended with a mass extinction of large megafauna such as the mammoth and the woolly rhinoceros. Note that the exact role of humans in megafaunal extinction remains contentious.

Pleistocene rewilding is a rewilding strategy that takes the Pleistocene (the period from roughly 2.5 million years ago until about 11,700 years ago) as its historical baseline for ecosystems. While Pleistocene rewilders draw inspiration from the species and functional complexity of ecosystems during the Pleistocene, they do not necessarily aim to recreate the exact same ecosystems as existed during this period. Pleistocene rewilding is associated with the reintroduction of large carnivores such as the wolf. It has mainly been promoted in North America and has its origins in the 3C-approach: an approach to rewilding that calls for the establishment of large cores (nature conservation areas where human interference is minimised), corridors that allow wildlife to travel between core areas, and the reintroduction of large carnivores. Pleistocene rewilding is contested as – depending on the context – it could give rise to human-wildlife conflicts and has been criticised for being based on views and principles that could lead to the marginalisation and displacement of rural and indigenous communities.

Polycultures consist of cultivating two or more crops (or animal species) on the same piece of land. Polycultures are often grown in groupings that either complement their nutritional needs or growing habit. Though polycultures have long been practiced in traditional farming systems around the world, the development of farm machinery, synthetic fertilisers and pesticides and a preference for simpler, more intensive systems that lend themselves well to economies of scale led to the displacement of polycultures in many contexts. Polycultures are associated with agroecology, regenerative agriculture and organic farming and are favoured for their role in enhancing biodiversity, improving soil health and reducing the need for chemical inputs.

Precision farming is an agricultural management practice that aims to supply plants or animals with precisely the amounts of agricultural inputs (e.g. water, pesticides, and fertilisers) they need at a specific location and moment in time, thereby increasing efficiency by reducing the total inputs needed for agricultural production, and reducing environmental impacts. Precision farming uses different types of technologies to measure, observe, and act upon factors that are relevant to the growth of crops and livestock. These can range from big data, GPS, robotics, sensors, and drones, to low-tech measures such as using bottle caps for applying the right amounts of fertilisers to individual plants. Aiming to optimize crop or livestock production, precision techniques include measuring, modelling, and responding to (site-specific) data, including weather forecasts, soil properties, soil water content, pests, and weeds.

Precision fermentation involves the production of certain molecules using genetically modified microbes, such as yeast, grown in bioreactors. It is used both in the medical field (such as to make insulin) and for food production (such as to make rennet and more recently dairy proteins and egg whites). In food production it contrasts with cellular agriculture in that it is the molecules produced by the cells, and not the cells themselves, which are used for human consumption.

Price elasticity refers to how much the demand for a good is affected by a change in its price. A good is said to be price inelastic if a change in price means that there is little change in demand. An example might be medication or addictive substances, like tobacco. A good is said to be price elastic if a change in price greatly changes the demand for the good.

Processed culinary ingredients is a category of food ingredients in the NOVA classification that result from the further treatment of unprocessed and minimally processed foods by processes such as pressing, refining, grinding, milling, and spray drying. Examples include salt, spices, cane sugar, flour, honey and olive oil. Processed culinary ingredients are added to other foods in the preparation of dishes. Advocates of NOVA understand their purpose to be enabling the preparation of more varied dishes from minimally processed foods and improving the taste and appearance of such dishes. Processed culinary ingredients are usually not consumed on their own.

The concept of processed food, in the public understanding, is often used loosely to refer to mass-produced ready-to-eat foods such as instant flavoured noodles and soda drinks. The concept, however, also refers to one of the four categories of the NOVA classification, which classifies many of these foods as ultra-processed foods. Within NOVA’s processed food category are minimally processed foods to which one or more processed culinary ingredient has been added, and which have been further modified by processes such as smoking, salting, and canning. Advocates of NOVA understand processed foods to be produced primarily to increase the durability of minimally processed foods and to enhance the taste and appearance of such foods. Examples of processed foods include freshly made breads, pickled vegetables, salted nuts, smoked meats, and canned fish.

Protein is one of the three macronutrients, the main components of food from which we get energy (the other two are fat and carbohydrate). In chemical terms, ‘proteins’ are a class of millions of different molecules which make up much of the physical structure of animal bodies and perform most complex biological tasks. However, from the point of view of nutrition, these are almost all broken down by the digestive system and can be constructed as needed from the resulting components. These components are the amino acids.

Protein-energy malnutrition refers to a spectrum of presentations of poor nutrition caused by insufficient intake of protein and/or calories. Specific protein malnutrition with sufficient energy intake (sometimes referred to as kwashiorkor, although this term has a complex history: see definition) characteristically presents with oedema (swelling). Undernourishment but with sufficient protein intake presents with loss of muscle mass and subcutaneous fat (referred to as marasmus). The combination of these, marasmic kwashiorkor or simply severe PEM, shows both sets of symptoms. In practice, it is often impossible to make such neat distinctions. The fact that forms of PEM are typically accompanied by comorbidities complicates the picture further.

Public procurement refers to the acquisition of goods, services or work by public bodies such as government agencies, hospitals, and schools, or by state owned enterprises such as railways or energy providers. Such spending can represent a substantial amount of taxpayers' money and of gross domestic product in many countries, and so how it is spent is a matter of public interest. Beause of this, changing public procurement is often seen as a way in which to influence business practices.

Radiative efficiency is a measure of ‘greenhouse strength’ for different greenhouse gases, defined as the change in radiative forcing per change in atmospheric concentration of a gas (in Watts per metre square per part per billion; W m^-2 ppb^-1).

Radiative forcing is the measure of how different factors (including greenhouse gases) change the balance between incoming and outgoing energy in the atmosphere. Expressed as the change in energy balance per unit area (in Watts per metre square; W m^-2) over a given timeframe – typically contemporary compared to preindustrial conditions.

Reconstituted meat is a paste- or liquid-like meat product that is produced from ground meat. Fat and excess water are separated from the meat using a centrifuge or an emulsifier (a machine used to produce the meat into a fine and homogeneous paste or liquid of a desired thickness). Reconstituted meat is mostly used as a basis for pet food and as a supplement in some meat products for human consumption (e.g. chicken nuggets and some sausages).

A reduction fishery catches wild fish to be converted into fishmeal and fish oil (often to supply the aquaculture sector), rather than catching fish for direct human consumption.

Reforestation refers to the spontaneous or intentional return of trees in an area that has lost its forest cover either as a result of deforestation by humans or in other ways such as wildfire or drought.

Reformulation refers to changes food manufacturers make to the production recipes of processed and ultra-processed food products to improve their nutritional profile. Examples of reformulation include replacing sugar with artificial sweeteners (e.g. aspartame or sucralose) to reduce the food’s energy content or reducing the amount of salt or saturated fat in a food product.

Regenerative agriculture aims to generate farming systems that improve soil health, increase biodiversity and sequester carbon through the use of practices such as cover crops, crop rotations, minimal tillage, organic compost, agroforestry and crop-livestock integration. Many of these practices are also associated with organic farming and agroecology. Various certification schemes are being developed which will specify the processes and outcomes required for products to be classified as ‘regenerative’

See regenerative agriculture, conservation grazing, rotational grazing, mob grazing and crop-livestock integration.

Reintroduced species are species that are introduced by humans into an ecosystem to replace a species of the same type that has gone (locally) extinct. A reintroduced species can either be of the same species type as the species that was lost or a related species with similar appearance and/or behaviour.

The concept of resilience, in the context of food system sustainability, refers to the ability of the food system to cope with and recover from socio-economic or environmental shocks and pressures. A resilient system has a certain degree of toughness and is able to bounce back against or adapt to disturbances. A resilient food system, for example, is able to keep providing food or other outputs such as livelihoods for farmers, drinking water, and biodiversity conservation under conditions of drought, a drop in food prices, war, climate change, the spread of virus in plants or animals, and so on. Resilience can be thought of at different scale levels. For example, what may be considered as resilient on a national level may not be understood to be resilient at a farm level. While some see resilience as synchronous with sustainability, others point out that a resilient system may also be one that resists needed transformation; an unsustainable status quo may in fact be resilient to change.

Rewilding is a broad concept that emerged in the 1990s in the field of conservation biology and which has evolved in recent years to encompass a range of visions on nature and the management of ecosystems. Rewilding revolves around the understanding that ‘nature’ has become marginalised throughout human history. The ambition of rewilding is to turn the tide: it aims to give land back to nature and change the management of ecosystems for them to become more resilient and autonomous. In doing so, rewilding aims to kickstart the restoration of global biodiversity and strengthen ecosystem functions such as flood protection and carbon sequestration. An important underlying objective for many rewilders is to create a ‘wilder’ Earth where humans will be able to experience nature more frequently and in new, more diverse ways. Common rewilding strategies include trophic rewilding (the restoration of complex trophic interactions between species kickstarted by the reintroduction of keystone species such as large carnivores or large herbivores) and passive rewilding (the spontaneous rewilding of ecosystems when land is left to its own devices). Rewilding is a contested term. Debate centers on the implications of rewilding for food production and for rural and indigenous communities. An important topic of discussion concerns the extent to which rewilding is compatible with farming and whether its large-scale adoption would require a substantial downscaling of agricultural land use. Further topics of debate include the goal of some rewilders to restore landscapes to a pre-human baseline (see Pleistocene and Holocene rewilding) and various proposals to reintroduce large carnivores (e.g. wolves and tigers) in places where these went extinct. While rewilders today do not always see their own approaches reflected in these discussions, critics of rewilding are in favour of alternative visions that seek to restore nature and biodiversity through approaches that they see to be more clearly based on the principle of social justice.

The right to food was initially recognised in the 1948 Universal Declaration of Human Rights. It has since been developed by the Food and Agriculture Organisation of the United Nations, who now recognise the importance of the right to adequate food, defining this as ‘regular, permanent and unrestricted access, either directly or by means of financial purchases, to quantitatively and qualitatively adequate and sufficient food corresponding to the cultural traditions of the people to which the consumer belongs, and which ensure a physical and mental, individual and collective, fulfilling and dignified life free of fear’.

Rotational grazing is a system in which pasture is split up into paddocks and grazing animals moved from paddock to paddock over time. The result of this is that any individual part of the pasture is not being grazed for a significant portion of the year, allowing it time to recover. See conservation grazing, regenerative grazing, and mob grazing.

A ruminant is a mammal with a four-compartmented stomach which enables it to acquire nutrients from plant-based food such as grasses, husks, and stalks. Examples of ruminants include cattle, sheep, goats, deer, giraffes, and camels. After swallowing, microbes in the ruminant’s rumen (its first stomach compartment) begin fermenting the food. This process generates fatty acids (nutrients which the ruminant absorbs through its rumen walls) and methane, which the ruminant eructs or burps. Through this process, ruminants are able to digest coarse cellulosic material which monogastrics and people cannot. Methane emissions from ruminants are a significant source of greenhouse gasses from ruminant-based livestock systems.

Selective breeding refers to the deliberate human practice of choosing which plants or animals to breed together, based on specific characteristics, in order to selectively enhance these characteristics (and their genetic basis) in their offspring.

Sensitivity and uncertainty analysis are an integral part of any modelling process. Sensitivity analysis varies the possible values of input variables to a model in order to understand the difference that these assumptions make to results and conclusions that can be drawn. Uncertainty analysis investigates the potential effects of lack of knowledge or potential errors in the model design.

Sentience is the ability to experience sensations and feelings (particularly positive and negative feelings like pain and pleasure). It is often seen as a prerequisite for moral consideration in debates on animal welfare and ethics.

Silting refers to the transport and deposition of sediment on the riverbed, which changes the dynamics of the water flow and can affect aquatic ecosystems.

See soil health.

Soil health refers to the state of the soil with regards to its capacity to support plant growth; in this sense, it is a synonym for the narrower term soil fertility. However it is also used to refer to the soil's capacity to provide other ecosystem services, such as contributing to carbon sequestration or flood management, and the role soil plays in a wider set of relationships in an ecosystem. In practice, soil health in agronomy is mostly a function of its contents of plant macronutrients (particularly nitrogen, phosphorus and potassium, NPK) and micronutrients, its proportion of organic carbon, and the microbial communities living within it. Soil in poor health might be soil lacking in some key nutrients, with a very low content of organic carbon, or with a limited or unbalanced microbial ecosystem.

The Brazilian Soy Moratorium (SoyM) is a multi-stakeholder initiative set up in 2006 by Greenpeace, the Brazilian Association of Vegetable Oil Industries (ABIOVE), and the National Association of Grain Exporters (ANEC). It was later joined by many other companies, civil society organisations, and the Brazilian government. Signatories to the moratorium take on the voluntary commitment not to buy soybeans grown on land in the Amazon that was deforested after 22 July 2008. The soy moratorium was initially renewed annually but extended in 2019 for an indefinite period. The moratorium has caused deforestation in the Amazon to decline to about one half to one third of the rate before the moratorium. Recent years, however, have seen an increase in deforestation in the Amazon. Deforestation levels were particularly high in the summer of 2019 due to an exceptional increase in forest fires. Only a small amount of the soy exported from the Brazilian Amazon is handled by traders who did not sign the Moratorium.

A specialist species is a plant or animal species that is able to thrive in only a limited variety of environmental conditions, or that has a limited diet. Unlike endemic species, populations of the same specialist species may be present at different geographical locations around the world.

Structural Adjustment Programs (SAPS) were introduced by the International Monetary Fund and World Bank in the 1980s in response to a series of economic crises in the global South. During this era, these institutions made access to loans by poor countries conditional on a set of economic policies that aimed to reduce state spending and open up their economies to international trade. Proponents of SAPs claimed that they would encourage economic growth; however they have been heavily criticised for undermining national sovereignty, deepening social inequality and further marginalising many poorer countries in the global economy.

Stunting is a medical condition where childhood growth and development is impaired as a result of inadequate nutrition, repeated infection, and inadequate psychosocial stimulation. Children are defined as stunted if their height for their age is abnormally low. Its effects can lead to an underdeveloped brain, poor cognition and educational attainment, as well as a higher risk of nutrition-related chronic diseases later in life.

Subsistence farming refers to rearing animals and growing crops only for your own consumption, without having any surplus to take to market as a source of cash income.

The substitution effect in economics refers to the idea that as prices increase or as a product becomes scarce, people will replace such items with substitutes that are cheaper or easier to access. In the context of diets, substitution effects refer to the changes in the environmental footprint of a person's diet, according to the relative impact of foods that are substituted for one another.

Sustainable intensification is a recently developed concept that is understood in different ways by its critics and supporters. A common understanding is that it denotes the principle of increasing or maintaining the productivity of agriculture on existing farmland while at the same time, reducing its environmental impacts. Understood in this way, SI designates a goal for the development of agricultural systems but does not, a priori, favour any particular agronomic route to achieve it. It may involve the intensification of different types of agricultural inputs (e.g. of knowledge, biotechnologies, labour, machinery) and apply these to different forms of agriculture (e.g. livestock or arable; agroecological or conventional). Forms of intensification that can be called sustainable intensification must lower environmental impacts and land use, relative to yields. However, for some, to merit the term ‘sustainable’ social, economic, and ethical criteria must also be considered.

A symbiotic relationship, or symbiosis, is any type of a close and long-term biological interaction between two biological organisms of different species, termed symbionts. There are three main types…

• Parasitism: symbiosis where one species benefits, and the other is harmed. Examples include both internal (e.g., worms) and external (e.g., ticks) parasites found on livestock like cattle, sheep, goats, and pigs. Some of these can be zoonotic (passed on to humans).
• Commensalism: symbiosis where one species benefits, and the other is neither harmed nor helped. An example is birds, such as cattle egrets, perching on or near grazing cattle and eating insects stirred up while they graze.
• Mutualism: symbiosis where both species benefit. Examples include pollination of flowering plants by animals, mycorrhizal interactions between a plant’s roots and fungi, and the relationship between leguminous plants and nitrogen-fixating bacteria.

System boundaries are subjective boundaries that define what is included within the system under analysis (and so counted) and what is external to the system (and so not counted). System boundaries have multiple dimensions, including what stages are focused on (e.g. production, distribution), what inputs and outputs are measured (e.g. land, greenhouse gases), what geographic locations are included, and more.

‘The Great Protein Fiasco’, from the title of a 1974 paper in The Lancet by Donald Mclaren, is the name given to the period in international development policy from the late 1950s until the early 1970s. Throughout this time, UN agencies including the WHO and FAO, national aid programmes and famine relief charities pursued policies which put a particular focus on protein, overseeing the development of novel, high-protein foods, and prioritising access to protein sources in delivering food aid. This policy consensus was motivated by three generally accepted beliefs: that kwashiorkor was the leading cause of child mortality around the world and was caused by specific protein malnutrition (see kwashiorkor); and that the world faced a ‘protein gap’, or was bound to do so as population increased (see the Protein Gap). All three of these assumptions were moderated or completely undermined as better evidence came to light, but even so it took some time for the policy consensus to change. In using the word ‘fiasco’ to describe his era, Mclaren was levelling the charge that a huge amount of time, energy and money had been wasted on narrowly protein-focused, technocratic solutions to world hunger that in the end had made little to no impact. His paper played a significant role in finally changing the focus of international development policy from the mid-1970s onwards.

Discounting refers to the practice of putting a present value on costs and benefits that will occur in the future. Economists generally value costs and benefits that are predicted to occur in the future less than those incurred in the present because it is assumed that economic growth will make people richer, on the whole, in the future than they are today. As such the value of a pound or dollar in the future will be worth relatively less. The lesser value economists assign to a future dollar also stems from the observation that because people are impatient and so they prefer income today over income tomorrow. There is much disagreement about how to set the discount rate and this disagreement has relevance for measures to address, for example, climate change. If the discount rate is set very high (i.e. the cost of a dollar tomorrow is much lower than it is today) then the upfront costs of tackling climate change will be judged to outweigh the future economic benefits of having avoided it. Some argue that discounting undermines the rights of future generations; turning fundamentally ethical issues into technical ones whilst wrongly assuming ecological crises will only marginally affect economic growth.

A tipping point, in ecological or geological terms, is a threshold at which a small “push” (such as additional greenhouse gas emissions) can lead to a runaway feedback loop, resulting in the sudden shift of a local ecosystem or the entire planet to a new state (say, a much hotter climate). These shifts may follow a pattern known as hysteresis, where is it much harder to reverse the shift than it is to cause it. For example, an ice sheet that melts rapidly due to climate change might take a long time to regrow even if climate change were to be reversed. Hence, tipping points could potentially result in environmental changes that are irreversible on human timescales.

Trophic interactions refer to the feeding and nutrient exchange relationships between organisms. Examples of trophic interactions include predation, grazing and parasitism.

Trophic rewilding is defined by the principle of restoring trophic interactions. These include predator-prey relationships in the food chain but also other processes such as scavenging or decaying that constitute nutrient flows in the ecosystem. Trophic rewilding aims for the diversification and increasing complexity of the web of such interactions. As such trophic rewilding is a broad concept that encompasses other rewilding strategies such as Pleistocene and Holocene rewilding. However, unlike these more specific strategies trophic rewilding does not seek to restore nature to a particular historical baseline and is silent on questions about scale.

Turbidity refers to the amount of light that can pass through water (i.e. its cloudiness), as a result of particles that are suspended within the fluid. It can vary naturally depending on location, but can have detrimental impacts on ecosystems if caused by human activity. For this reason, it is often used as an indicator of water quality.

Ultra-processed food (UPF) generally refers to one of the four categories of the NOVA food classification (see below) and are used loosely to refer to snacks and fast foods. NOVA describes UPFs as ‘industrial formulations’ of food products, typically mass-produced, that contain few ‘natural’ ingredients. Advocates of NOVA point out that UPFs consist of many additives and food-derived ingredients such as whey, protein isolates, and invert sugar, which are produced and combined through processes that are uncommon in domestic kitchens. They understand these foods to be designed so as to be so appealing that they displace the consumption of healthier, less processed foods, thereby generating high profits for their manufacturers. Foods in the UPF category include biscuits, mass-produced buns and breads, sweetened cereals, margarines and spreads, packaged snacks, ice cream, flavoured yogurts, soft drinks, powdered meals, ready-made meals, and instant sauces and stocks. Proponents of the concept have argued that the consumption of UPF is the primary driver of the global ‘pandemic’ of overweight and obesity while contributing to non-communicable diseases such as metabolic syndrome and certain cancers. It has been argued that the production and consumption of UPFs undermine social and environmental sustainability while perpetuating unequal power dynamics in the food system. Opponents of the concept have contested these claims. They argue that the concept is imprecise and groups together foods with different nutritional characteristics.

Undernutrition refers to deficiencies of a particular component of food, usually due to insufficient intake and/or absorption of that component. This usually refers to energy (often measured in calories) or macronutrients (such as protein, carbohydrates, or fat), but can also refer to micronutrients (vitamins or minerals).

The General Agreement on Tariffs and Trade (GATT) is a legal agreement introduced in 1947 to encourage international trade. Prior to the Uruguay round of negotiations, which took place between 1986 and 1994, agricultural products had been effectively exempt from GATT rules. However, the Uruguay negotiations led to the Agreement on Agriculture, which opened up agricultural markets by reducing tariffs on agricultural goods and limiting government subsidies for agricultural exports and domestic production. This agreement has been widely criticised, particularly by the food sovereignty movement, for having negative impacts on smallholder farmers and poorer countries. Following the Uruguay round of negotiations, GATT was replaced by the World Trade Organisation.

Water footprint is a metric that quantifies the amount of water used to produce each of the goods and services we use. It allows these goods and services to be compared in terms of their water impact, and so to the impact on limited water resources of consumption by individuals, organisations, and even nation states. Water footprints incorporate all the water used – i.e. unable to be used again due to evaporation or removal in products – across the full lifecycle of a produce from production through to consumption, including all inputs to production (e.g. feed crops used in pork production). It has three components: (1) green water - rainwater used in soils; (2) blue water - freshwater sources; (3) grey water - water amount needed to dilute pollution to safe levels.

The World Health Assembly is the forum through which the World Health Organisation is governed.

Wildlife-friendly farming, while a fairly informal term, generally refers to an approach to farming that aims to support both food production and the conservation of biodiversity on farmland. Wildlife-friendly farming is associated with the use of reduced chemical and fertiliser inputs and the preservation of native vegetation (e.g. flowers, trees, and bushes) on or around farmland. Those who use the term tend to equate wildlife-friendly farming with a land sharing approach. Related although not synonymous terms include organic farming and agroecology.

The World Health Organisation (WHO) is a specialised branch of the United Nations. It is dedicated to improving public health worldwide.

An international organisation that regulates and facilitates global trade. Its membership (and the source of its operating budget) includes 164 countries, which comprise the parties in the vast majority of global trading relationships. Its goals are broadly to reduce barriers to trade such as tariffs and to ensure that trade occurs in a transparent, rule-governed system. It is simultaneously seen by some as an important vehicle for decreasing global economic inequality by encouraging free trade, and by others as an important contributor to global economic inequality by facilitating exploitative practices and the continued flow of capital into wealthy countries.

The yield gap is the difference between the actual productivity of a given area of farmland and the maximum productivity that could in principle be achieved using agricultural practices, resources, and technologies that are currently available. The best yields that can be obtained locally depend on the capacity of farmers to access and use, among other things, land, seeds, water, nutrients, pest management, soils, biodiversity, and knowledge. Yield gaps are studied and measured at various scales - from the farm through to the national and global levels.

Minimal-tillage or Zero-tillage farming refers to the farming of crops with little to no soil disturbance through tillage. Tilling methods include such activities as shovelling and ploughing or the use of cultivators to crush clods and smoothen the soil. Zero-tillage farming requires fewer machinery inputs and related energy use, and often less human labour per unit of output. Tillage is used to eliminate weeds, and zero-tillage farming is often associated with higher pesticide and herbicide levels. Zero-tillage farming is particularly associated with the production of genetically modified crops and the use of glyphosate-based broad-spectrum herbicides such as Roundup that kill many different types of weeds. It is also associated with some more 'nature-based' agricultural movements, such as regenerative agriculture and permaculture.

Zoonotic diseases are pathogens (e.g. viruses, bacteria, fungi, parasites) which can – to varying degrees – be transmitted between animals and human. Examples include bird and swine flu, lyme disease, bovine tuberculosis, rabies, and zika.