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.