Biodiversity lossBiodiversity loss includes the worldwide extinction of different species, as well as the local reduction or loss of species in a certain habitat, resulting in a loss of biological diversity. The latter phenomenon can be temporary or permanent, depending on whether the environmental degradation that leads to the loss is reversible through ecological restoration/ecological resilience or effectively permanent (e.g. through land loss).
OverexploitationOverexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity.
Habitat destructionHabitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby reducing biodiversity and species abundance. Habitat destruction is the leading cause of biodiversity loss. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as they are major threats to the survival of endangered species.
Human impact on the environmentHuman impact on the environment (or anthropogenic environmental impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society (as in the built environment) is causing severe effects including global warming, environmental degradation (such as ocean acidification), mass extinction and biodiversity loss, ecological crisis, and ecological collapse.
AfricaAfrica is the world's second-largest and second-most populous continent, after Asia in both aspects. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surface area. With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4.
HumanHumans, or modern humans (Homo sapiens), are the most common and widespread species of primate. A great ape characterized by their hairlessness, bipedalism, and high intelligence, humans have a large brain and resulting cognitive skills that enable them to thrive in varied environments and develop complex societies and civilizations. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states.
Overconsumption (economics)Overconsumption describes a situation where a consumer overuses their available goods and services to where they can't, or don't want to, replenish or reuse them. In microeconomics, this may be described as the point where the marginal cost of a consumer is greater than their marginal utility. The term overconsumption is quite controversial in use and does not necessarily have a single unifying definition. When used to refer to natural resources to the point where the environment is negatively affected, is it synonymous with the term overexploitation.
LivestockLivestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals who are raised for consumption, and sometimes used to refer solely to farmed ruminants, such as cattle, sheep, goats, and pigs. Horses are considered livestock in the United States. The USDA classifies pork, veal, beef, and lamb (mutton) as livestock, and all livestock as red meat.
Habitat fragmentationHabitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species.
Environmental degradationEnvironmental degradation is the deterioration of the environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. Environmental concerns can be defined as the negative effects of any human activity on the environment. The biological as well as the physical features of the environment are included.
Natural environmentThe natural environment or natural world encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity.
PoachingPoaching is the illegal hunting or capturing of wild animals, usually associated with land use rights. Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set against the hunting privileges of nobility and territorial rulers. Since the 1980s, the term "poaching" has also been used to refer to the illegal harvesting of wild plants.
Holocene extinctionThe Holocene extinction, or Anthropocene extinction, is the ongoing extinction event during the Holocene epoch. The extinctions span numerous families of plants and animals, including mammals, birds, reptiles, amphibians, fish, invertebrates, and affecting not just terrestrial species but also large sectors of marine life. With widespread degradation of biodiversity hotspots, such as coral reefs and rainforests, as well as other areas, the vast majority of these extinctions are thought to be undocumented, as the species are undiscovered at the time of their extinction, which goes unrecorded.
Human overpopulationHuman overpopulation (or human population overshoot) describes a concern that human populations may become too large to be sustained by their environment or resources in the long term. The topic is usually discussed in the context of world population, though it may concern individual nations, regions, and cities. Since 1804, the global human population has increased from 1 billion to 8 billion due to medical advancements and improved agricultural productivity. Annual world population growth peaked at 2.
WildernessWilderness or wildlands (usually in the plural) are natural environments on Earth that have not been significantly modified by human activity, or any nonurbanized land not under extensive agricultural cultivation. The term has traditionally referred to terrestrial environments, though growing attention is being placed on marine wilderness. Recent maps of wilderness suggest it covers roughly one-quarter of Earth's terrestrial surface, but is being rapidly degraded by human activity.
Game (hunting)Game or quarry is any wild animal hunted for animal products (primarily meat), for recreation ("sporting"), or for trophies. The species of animals hunted as game varies in different parts of the world and by different local jurisdictions, though most are terrestrial mammals and birds. Fish caught non-commercially (recreational fishing) are also referred to as game fish. The range of animal species hunted by humans varies in different parts of the world.
Natural resourceNatural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. On Earth, it includes sunlight, atmosphere, water, land, all minerals along with all vegetation, and wildlife. Natural resources are part of humanity's natural heritage or protected in nature reserves. Particular areas (such as the rainforest in Fatu-Hiva) often feature biodiversity and geodiversity in their ecosystems.
Endangered speciesAn endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas.
DeforestationDeforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century.
BiodiversityBiodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (genetic variability), species (species diversity), and ecosystem (ecosystem diversity) level. Biodiversity is not distributed evenly on Earth; it is usually greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than 10% of earth's surface and contain about 90% of the world's species.
