The Holocene extinction, or Anthropocene extinction, is the ongoing extinction event caused by humans during the Holocene epoch. These extinctions span numerous families of plants and animals, including mammals, birds, reptiles, amphibians, fish, and 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. The current rate of extinction of species is estimated at 100 to 1,000 times higher than natural background extinction rates and is increasing. During the past 100–200 years, biodiversity loss and species extinction have accelerated, to the point that most conservation biologists now believe that human activity has either produced a period of mass extinction, or is on the cusp of doing so. As such, after the "Big Five" mass extinctions, the Holocene extinction event has also been referred to as the sixth mass extinction or sixth extinction; given the recent recognition of the Capitanian mass extinction, the term seventh mass extinction has also been proposed for the Holocene extinction event.
Biodiversity is the variability of life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and phylogenetic diversity. Diversity is not distributed evenly on Earth. It is 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 one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are latitudinal gradients in species diversity for both marine and terrestrial taxa.
Protected areas or conservation areas are locations which receive protection because of their recognized natural or cultural values. Protected areas are those areas in which human presence or the exploitation of natural resources is limited.
Conservation in Australia is an issue of state and federal policy. Australia is one of the most biologically diverse countries in the world, with a large portion of species endemic to Australia. Preserving this wealth of biodiversity is important for future generations. 25% of Australia is managed for conservation.
Wildlife refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted for sport. Wildlife can be found in all ecosystems. Deserts, plains, grasslands, woodlands, forests, and other areas including the most developed urban areas, all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that much wildlife is affected by human activities. Some wildlife threaten human safety, health, property and quality of life. However, many wild animals, even the dangerous ones, have value to human beings. This value might be economic, educational, or emotional in nature.
Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.
The ecological footprint measures human demand on natural capital, i.e. the quantity of nature it takes to support people and their economies. It tracks human demand on nature through an ecological accounting system. The accounts contrast the biologically productive area people use to satisfy their consumption to the biologically productive area available within a region, nation, or the world (biocapacity). Biocapacity is the productive area that can regenerate what people demand from nature. Therefore, the metric is a measure of human impact on the environment. As Ecological Footprint accounts measure to what extent human activities operate within the means of our planet, they are a central metric for sustainability.
Environmental 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. The environmental degradation process amplifies the impact of environmental issues which leave lasting impacts on the environment.
Human impact on the environment 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 is causing severe effects including global warming, environmental degradation, mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage to the environment on a global scale include population growth, neoliberal economic policies and rapid economic growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species.
Wildlife conservation refers to the practice of protecting wild species and their habitats in order to maintain healthy wildlife species or populations and to restore, protect or enhance natural ecosystems. Major threats to wildlife include habitat destruction, degradation, fragmentation, overexploitation, poaching, pollution, climate change, and the illegal wildlife trade. The IUCN estimates that 42,100 species of the ones assessed are at risk for extinction. Expanding to all existing species, a 2019 UN report on biodiversity put this estimate even higher at a million species. It is also being acknowledged that an increasing number of ecosystems on Earth containing endangered species are disappearing. To address these issues, there have been both national and international governmental efforts to preserve Earth's wildlife. Prominent conservation agreements include the 1973 Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the 1992 Convention on Biological Diversity (CBD). There are also numerous nongovernmental organizations (NGO's) dedicated to conservation such as the Nature Conservancy, World Wildlife Fund, and Conservation International.
Environmental vegetarianism is the practice of vegetarianism that is motivated by the desire to create a sustainable diet, which avoids the negative environmental impact of meat production. Livestock as a whole is estimated to be responsible for around 15% of global greenhouse gas emissions. As a result, significant reduction in meat consumption has been advocated by, among others, the Intergovernmental Panel on Climate Change in their 2019 special report and as part of the 2017 World Scientists' Warning to Humanity.
Human overpopulation is the idea 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.
Wildlife trade refers to the products that are derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, tissues such as skins, bones or meat, or other products. Legal wildlife trade is regulated by the United Nations' Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which currently has 184 member countries called Parties. Illegal wildlife trade is widespread and constitutes one of the major illegal economic activities, comparable to the traffic of drugs and weapons.
The Living Planet Index (LPI) is an indicator of the state of global biological diversity, based on trends in vertebrate populations of species from around the world. The Zoological Society of London (ZSL) manages the index in cooperation with the World Wide Fund for Nature (WWF).
Defaunation is the global, local, or functional extinction of animal populations or species from ecological communities. The growth of the human population, combined with advances in harvesting technologies, has led to more intense and efficient exploitation of the environment. This has resulted in the depletion of large vertebrates from ecological communities, creating what has been termed "empty forest". Defaunation differs from extinction; it includes both the disappearance of species and declines in abundance. Defaunation effects were first implied at the Symposium of Plant-Animal Interactions at the University of Campinas, Brazil in 1988 in the context of Neotropical forests. Since then, the term has gained broader usage in conservation biology as a global phenomenon.
The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. WWF is the world's largest conservation organization, with over five million supporters worldwide, working in more than 100 countries and supporting around 3,000 conservation and environmental projects. They have invested over $1 billion in more than 12,000 conservation initiatives since 1995. WWF is a foundation with 65% of funding from individuals and bequests, 17% from government sources and 8% from corporations in 2020.
Biodiversity loss happens when plant or animal species disappear completely from Earth (extinction) or when there is a decrease or disappearance of species in a specific area. Biodiversity loss means that there is a reduction in biological diversity in a given area. The decrease can be temporary or permanent. It is temporary if the damage that led to the loss is reversible in time, for example through ecological restoration. If this is not possible, then the decrease is permanent. The cause of most of the biodiversity loss is, generally speaking, human activities that push the planetary boundaries too far. These activities include habitat destruction and land use intensification. Further problem areas are air and water pollution, over-exploitation, invasive species and climate change.
The Global Assessment Report on Biodiversity and Ecosystem Services is a report by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, on the global state of biodiversity. A summary for policymakers was released on 6 May 2019. The report states that, due to human impact on the environment in the past half-century, the Earth's biodiversity has suffered a catastrophic decline unprecedented in human history, as an estimated 82 percent of wild mammal biomass has been lost. The report estimates that there are 8 million animal and plant species on Earth, with the majority represented by insects. Out of those 8 million species, 1 million are threatened with extinction, including 40 percent of amphibians, almost a third of reef-building corals, more than a third of marine mammals, and 10 percent of all insects.
Maria Dornelas FRSE is a researcher in biodiversity and professor of biology based at St. Andrew's University. She was made a Fellow of the Royal Society of Edinburgh in 2021. Her research into biodiversity change has challenged previous views, on the growth and decline of coral reefs to understanding global biodiversity with data analysis on how species or ecosystems are changing in the Anthropocene.
The decline of wild mammal populations globally has been an occurrence spanning over the past 50,000 years, at the same time as the populations of humans and livestock have increased. Nowadays, the total biomass of wild mammals on land is believed to be seven times lower than its prehistoric values, while the biomass of marine mammals had declined fivefold. At the same time, the biomass of humans is "an order of magnitude higher than that of all wild mammals", and the biomass of livestock mammals like pigs and cattle is even larger than that. Even as wild mammals had declined, the growth in the numbers of humans and livestock had increased total mammal biomass fourfold. Only 4% of that increased number are wild mammals, while livestock and humans amount to 60% and 36%. Alongside the simultaneous halving of plant biomass, these striking declines are considered part of the prehistoric phase of the Holocene extinction.
