Nature, in the broadest sense, is the natural, physical, or material world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena.
The word nature is derived from the Latin word natura, or "essential qualities, innate disposition", and in ancient times, literally meant "birth". Natura is a Latin translation of the Greek word physis (φύσις), which originally related to the intrinsic characteristics that plants, animals, and other features of the world develop of their own accord. The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-Socratic philosophers, and has steadily gained currency ever since. This usage continued during the advent of modern scientific method in the last several centuries.
Within the various uses of the word today, "nature" often refers to geology and wildlife. Nature can refer to the general realm of living plants and animals, and in some cases to the processes associated with inanimate objects—the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth. It is often taken to mean the "natural environment" or wilderness—wild animals, rocks, forest, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention. For example, manufactured objects and human interaction generally are not considered part of nature, unless qualified as, for example, "human nature" or "the whole of nature". This more traditional concept of natural things which can still be found today implies a distinction between the natural and the artificial, with the artificial being understood as that which has been brought into being by a human consciousness or a human mind. Depending on the particular context, the term "natural" might also be distinguished from the unnatural or the supernatural.
Earth is the only planet known to support life, and its natural features are the subject of many fields of scientific research. Within the solar system, it is third closest to the sun; it is the largest terrestrial planet and the fifth largest overall. Its most prominent climatic features are its two large polar regions, two relatively narrow temperate zones, and a wide equatorial tropical to subtropical region. Precipitation varies widely with location, from several metres of water per year to less than a millimetre. 71 percent of the Earth's surface is covered by salt-water oceans. The remainder consists of continents and islands, with most of the inhabited land in the Northern Hemisphere.
Earth has evolved through geological and biological processes that have left traces of the original conditions. The outer surface is divided into several gradually migrating tectonic plates. The interior remains active, with a thick layer of plastic mantle and an iron-filled core that generates a magnetic field. This iron core is composed of a solid inner phase, and a fluid outer phase. Convective motion in the core generates electric currents through dynamo action, and these, in turn, generate the geomagnetic field.
The atmospheric conditions have been significantly altered from the original conditions by the presence of life-forms, which create an ecological balance that stabilizes the surface conditions. Despite the wide regional variations in climate by latitude and other geographic factors, the long-term average global climate is quite stable during interglacial periods, and variations of a degree or two of average global temperature have historically had major effects on the ecological balance, and on the actual geography of the Earth.
Geology is the science and study of the solid and liquid matter that constitutes the Earth. The field of geology encompasses the study of the composition, structure, physical properties, dynamics, and history of Earth materials, and the processes by which they are formed, moved, and changed. The field is a major academic discipline, and is also important for mineral and hydrocarbon extraction, knowledge about and mitigation of natural hazards, some Geotechnical engineering fields, and understanding past climates and environments.
The geology of an area evolves through time as rock units are deposited and inserted and deformational processes change their shapes and locations.
Rock units are first emplaced either by deposition onto the surface or intrude into the overlying rock. Deposition can occur when sediments settle onto the surface of the Earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows, blanket the surface. Igneous intrusions such as batholiths, laccoliths, dikes, and sills, push upwards into the overlying rock, and crystallize as they intrude.
After the initial sequence of rocks has been deposited, the rock units can be deformed and/or metamorphosed. Deformation typically occurs as a result of horizontal shortening, horizontal extension, or side-to-side (strike-slip) motion. These structural regimes broadly relate to convergent boundaries, divergent boundaries, and transform boundaries, respectively, between tectonic plates.
Earth is estimated to have formed 4.54 billion years ago from the solar nebula, along with the Sun and other planets. The moon formed roughly 20 million years later. Initially molten, the outer layer of the Earth cooled, resulting in the solid crust. Outgassing and volcanic activity produced the primordial atmosphere. Condensing water vapor, most or all of which came from ice delivered by comets, produced the oceans and other water sources. The highly energetic chemistry is believed to have produced a self-replicating molecule around 4 billion years ago.
Continents formed, then broke up and reformed as the surface of Earth reshaped over hundreds of millions of years, occasionally combining to make a supercontinent. Roughly 750 million years ago, the earliest known supercontinent Rodinia, began to break apart. The continents later recombined to form Pannotia which broke apart about 540 million years ago, then finally Pangaea, which broke apart about 180 million years ago.
During the Neoproterozoic era, freezing temperatures covered much of the Earth in glaciers and ice sheets. This hypothesis has been termed the "Snowball Earth", and it is of particular interest as it precedes the Cambrian explosion in which multicellular life forms began to proliferate about 530–540 million years ago.
Since the Cambrian explosion there have been five distinctly identifiable mass extinctions. The last mass extinction occurred some 66 million years ago, when a meteorite collision probably triggered the extinction of the non-avian dinosaurs and other large reptiles, but spared small animals such as mammals. Over the past 66 million years, mammalian life diversified.
Several million years ago, a species of small African ape gained the ability to stand upright. The subsequent advent of human life, and the development of agriculture and further civilization allowed humans to affect the Earth more rapidly than any previous life form, affecting both the nature and quantity of other organisms as well as global climate. By comparison, the Great Oxygenation Event, produced by the proliferation of algae during the Siderian period, required about 300 million years to culminate.
The present era is classified as part of a mass extinction event, the Holocene extinction event, the fastest ever to have occurred. Some, such as E. O. Wilson of Harvard University, predict that human destruction of the biosphere could cause the extinction of one-half of all species in the next 100 years. The extent of the current extinction event is still being researched, debated and calculated by biologists.
The Earth's atmosphere is a key factor in sustaining the ecosystem. The thin layer of gases that envelops the Earth is held in place by gravity. Air is mostly nitrogen, oxygen, water vapor, with much smaller amounts of carbon dioxide, argon, etc. The atmospheric pressure declines steadily with altitude. The ozone layer plays an important role in depleting the amount of ultraviolet (UV) radiation that reaches the surface. As DNA is readily damaged by UV light, this serves to protect life at the surface. The atmosphere also retains heat during the night, thereby reducing the daily temperature extremes.
Terrestrial weather occurs almost exclusively in the lower part of the atmosphere, and serves as a convective system for redistributing heat. Ocean currents are another important factor in determining climate, particularly the major underwater thermohaline circulation which distributes heat energy from the equatorial oceans to the polar regions. These currents help to moderate the differences in temperature between winter and summer in the temperate zones. Also, without the redistributions of heat energy by the ocean currents and atmosphere, the tropics would be much hotter, and the polar regions much colder.
Weather can have both beneficial and harmful effects. Extremes in weather, such as tornadoes or hurricanes and cyclones, can expend large amounts of energy along their paths, and produce devastation. Surface vegetation has evolved a dependence on the seasonal variation of the weather, and sudden changes lasting only a few years can have a dramatic effect, both on the vegetation and on the animals which depend on its growth for their food.
Climate is a measure of the long-term trends in the weather. Various factors are known to influence the climate, including ocean currents, surface albedo, greenhouse gases, variations in the solar luminosity, and changes to the Earth's orbit. Based on historical records, the Earth is known to have undergone drastic climate changes in the past, including ice ages.
The climate of a region depends on a number of factors, especially latitude. A latitudinal band of the surface with similar climatic attributes forms a climate region. There are a number of such regions, ranging from the tropical climate at the equator to the polar climate in the northern and southern extremes. Weather is also influenced by the seasons, which result from the Earth's axis being tilted relative to its orbital plane. Thus, at any given time during the summer or winter, one part of the Earth is more directly exposed to the rays of the sun. This exposure alternates as the Earth revolves in its orbit. At any given time, regardless of season, the northern and southern hemispheres experience opposite seasons.
Weather is a chaotic system that is readily modified by small changes to the environment, so accurate weather forecasting is limited to only a few days. Overall, two things are happening worldwide: (1) temperature is increasing on the average; and (2) regional climates have been undergoing noticeable changes.
Water is a chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor, or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large bodies of water, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds, and precipitation. Oceans hold 97% of surface water, glaciers, and polar ice caps 2.4%, and other land surface water such as rivers, lakes, and ponds 0.6%. Additionally, a minute amount of the Earth's water is contained within biological bodies and manufactured products.
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface (an area of some 361 million square kilometers) is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas. More than half of this area is over 3,000 meters (9,800 feet) deep. Average oceanic salinity is around 35 parts per thousand (ppt) (3.5%), and nearly all seawater has a salinity in the range of 30 to 38 ppt. Though generally recognized as several 'separate' oceans, these waters comprise one global, interconnected body of salt water often referred to as the World Ocean or global ocean. This concept of a global ocean as a continuous body of water with relatively free interchange among its parts is of fundamental importance to oceanography.
The major oceanic divisions are defined in part by the continents, various archipelagos, and other criteria: these divisions are (in descending order of size) the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean. Smaller regions of the oceans are called seas, gulfs, bays and other names. There are also salt lakes, which are smaller bodies of landlocked saltwater that are not interconnected with the World Ocean. Two notable examples of salt lakes are the Aral Sea and the Great Salt Lake.
A lake (from Latin lacus) is a terrain feature (or physical feature), a body of liquid on the surface of a world that is localized to the bottom of basin (another type of landform or terrain feature; that is, it is not global) and moves slowly if it moves at all. On Earth, a body of water is considered a lake when it is inland, not part of the ocean, is larger and deeper than a pond, and is fed by a river. The only world other than Earth known to harbor lakes is Titan, Saturn's largest moon, which has lakes of ethane, most likely mixed with methane. It is not known if Titan's lakes are fed by rivers, though Titan's surface is carved by numerous river beds. Natural lakes on Earth are generally found in mountainous areas, rift zones, and areas with ongoing or recent glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world, there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens designed for aesthetic ornamentation, fish ponds designed for commercial fish breeding, and solar ponds designed to store thermal energy. Ponds and lakes are distinguished from streams via current speed. While currents in streams are easily observed, ponds and lakes possess thermally driven micro-currents and moderate wind driven currents. These features distinguish a pond from many other aquatic terrain features, such as stream pools and tide pools.
A river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including stream, creek, brook, rivulet, and rill; there is no general rule that defines what can be called a river. Many names for small rivers are specific to geographic location; one example is Burn in Scotland and North-east England. Sometimes a river is said to be larger than a creek, but this is not always the case, due to vagueness in the language. A river is part of the hydrological cycle. Water within a river is generally collected from precipitation through surface runoff, groundwater recharge, springs, and the release of stored water in natural ice and snowpacks (i.e., from glaciers).
A stream is a flowing body of water with a current, confined within a bed and stream banks. In the United States, a stream is classified as a watercourse less than 60 feet (18 metres) wide. Streams are important as conduits in the water cycle, instruments in groundwater recharge, and they serve as corridors for fish and wildlife migration. The biological habitat in the immediate vicinity of a stream is called a riparian zone. Given the status of the ongoing Holocene extinction, streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity. The study of streams and waterways in general involves many branches of inter-disciplinary natural science and engineering, including hydrology, fluvial geomorphology, aquatic ecology, fish biology, riparian ecology, and others.
Ecosystems are composed of a variety of abiotic and biotic components that function in an interrelated way. The structure and composition is determined by various environmental factors that are interrelated. Variations of these factors will initiate dynamic modifications to the ecosystem. Some of the more important components are: soil, atmosphere, radiation from the sun, water, and living organisms.
Central to the ecosystem concept is the idea that living organisms interact with every other element in their local environment. Eugene Odum, a founder of ecology, stated: "Any unit that includes all of the organisms (ie: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (i.e.: exchange of materials between living and nonliving parts) within the system is an ecosystem." Within the ecosystem, species are connected and dependent upon one another in the food chain, and exchange energy and matter between themselves as well as with their environment. The human ecosystem concept is based on the human/nature dichotomy and the idea that all species are ecologically dependent on each other, as well as with the abiotic constituents of their biotope.
Wilderness is generally defined as areas that have not been significantly modified by human activity. Wilderness areas can be found in preserves, estates, farms, conservation preserves, ranches, national forests, national parks, and even in urban areas along rivers, gulches, or otherwise undeveloped areas. Wilderness areas and protected parks are considered important for the survival of certain species, ecological studies, conservation, and solitude. Some nature writers believe wilderness areas are vital for the human spirit and creativity, and some ecologists consider wilderness areas to be an integral part of the Earth's self-sustaining natural ecosystem (the biosphere). They may also preserve historic genetic traits and that they provide habitat for wild flora and fauna that may be difficult or impossible to recreate in zoos, arboretums, or laboratories.
Although there is no universal agreement on the definition of life, scientists generally accept that the biological manifestation of life is characterized by organization, metabolism, growth, adaptation, response to stimuli, and reproduction. Life may also be said to be simply the characteristic state of organisms.
Properties common to terrestrial organisms (plants, animals, fungi, protists, archaea, and bacteria) are that they are cellular, carbon-and-water-based with complex organization, having a metabolism, a capacity to grow, respond to stimuli, and reproduce. An entity with these properties is generally considered life. However, not every definition of life considers all of these properties to be essential. Human-made analogs of life may also be considered to be life.
The biosphere is the part of Earth's outer shell—including land, surface rocks, water, air and the atmosphere—within which life occurs, and which biotic processes in turn alter or transform. From the broadest geophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere (rocks), hydrosphere (water), and atmosphere (air). The entire Earth contains over 75 billion tons (150 trillion pounds or about 6.8×1013 kilograms) of biomass (life), which lives within various environments within the biosphere.
Over nine-tenths of the total biomass on Earth is plant life, on which animal life depends very heavily for its existence. More than 2 million species of plant and animal life have been identified to date, and estimates of the actual number of existing species range from several million to well over 50 million. The number of individual species of life is constantly in some degree of flux, with new species appearing and others ceasing to exist on a continual basis. The total number of species is in rapid decline.
The origin of life on Earth is not well understood, but it is known to have occurred at least 3.5 billion years ago, during the hadean or archean eons on a primordial Earth that had a substantially different environment than is found at present. These life forms possessed the basic traits of self-replication and inheritable traits. Once life had appeared, the process of evolution by natural selection resulted in the development of ever-more diverse life forms.
Species that were unable to adapt to the changing environment and competition from other life forms became extinct. However, the fossil record retains evidence of many of these older species. Current fossil and DNA evidence shows that all existing species can trace a continual ancestry back to the first primitive life forms.
When basic forms of plant life developed the process of photosynthesis the sun's energy could be harvested to create conditions which allowed for more complex life forms. The resultant oxygen accumulated in the atmosphere and gave rise to the ozone layer. The incorporation of smaller cells within larger ones resulted in the development of yet more complex cells called eukaryotes. Cells within colonies became increasingly specialized, resulting in true multicellular organisms. With the ozone layer absorbing harmful ultraviolet radiation, life colonized the surface of Earth.
The first form of life to develop on the Earth were microbes, and they remained the only form of life until about a billion years ago when multi-cellular organisms began to appear. Microorganisms are single-celled organisms that are generally microscopic, and smaller than the human eye can see. They include Bacteria, Fungi, Archaea, and Protista.
These life forms are found in almost every location on the Earth where there is liquid water, including in the Earth's interior. Their reproduction is both rapid and profuse. The combination of a high mutation rate and a horizontal gene transfer ability makes them highly adaptable, and able to survive in new environments, including outer space. They form an essential part of the planetary ecosystem. However, some microorganisms are pathogenic and can post health risk to other organisms.
Originally Aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. In Linnaeus' system, these became the kingdoms Vegetabilia (later Plantae) and Animalia. Since then, it has become clear that the Plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. However, these are still often considered plants in many contexts. Bacterial life is sometimes included in flora, and some classifications use the term bacterial flora separately from plant flora.
Among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants
of plant life from a previous era. People in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain.
Regional floras commonly are divided into categories such as native flora and agricultural and garden flora, the lastly mentioned of which are intentionally grown and cultivated. Some types of "native flora" actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. This is an example of how human interaction with nature can blur the boundary of what is considered nature.
Another category of plant has historically been carved out for weeds. Though the term has fallen into disfavor among botanists as a formal way to categorize "useless" plants, the informal use of the word "weeds" to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. Similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life.
Animals as a category have several characteristics that generally set them apart from other living things. Animals are eukaryotic and usually multicellular (although see Myxozoa), which separates them from bacteria, archaea, and most protists. They are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae. They are also distinguished from plants, algae, and fungi by lacking cell walls.
With a few exceptions—most notably the two phyla consisting of sponges and placozoans—animals have bodies that are differentiated into tissues. These include muscles, which are able to contract and control locomotion, and a nervous system, which sends and processes signals. There is also typically an internal digestive chamber. The eukaryotic cells possessed by all animals are surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. This may be calcified to form structures like shells, bones, and spicules, a framework upon which cells can move about and be reorganized during development and maturation, and which supports the complex anatomy required for mobility.
Although humans comprise only a minuscule proportion of the total living biomass on Earth, the human effect on nature is disproportionately large. Because of the extent of human influence, the boundaries between what humans regard as nature and "made environments" is not clear cut except at the extremes. Even at the extremes, the amount of natural environment that is free of discernible human influence is diminishing at an increasingly rapid pace.
The development of technology by the human race has allowed the greater exploitation of natural resources and has helped to alleviate some of the risk from natural hazards. In spite of this progress, however, the fate of human civilization remains closely linked to changes in the environment. There exists a highly complex feedback loop between the use of advanced technology and changes to the environment that are only slowly becoming understood. Man-made threats to the Earth's natural environment include pollution, deforestation, and disasters such as oil spills. Humans have contributed to the extinction of many plants and animals.
Humans employ nature for both leisure and economic activities. The acquisition of natural resources for industrial use remains a sizable component of the world's economic system. Some activities, such as hunting and fishing, are used for both sustenance and leisure, often by different people. Agriculture was first adopted around the 9th millennium BCE. Ranging from food production to energy, nature influences economic wealth.
Although early humans gathered uncultivated plant materials for food and employed the medicinal properties of vegetation for healing, most modern human use of plants is through agriculture. The clearance of large tracts of land for crop growth has led to a significant reduction in the amount available of forestation and wetlands, resulting in the loss of habitat for many plant and animal species as well as increased erosion.
Beauty in nature has historically been a prevalent theme in art and books, filling large sections of libraries and bookstores. That nature has been depicted and celebrated by so much art, photography, poetry, and other literature shows the strength with which many people associate nature and beauty. Reasons why this association exists, and what the association consists of, are studied by the branch of philosophy called aesthetics. Beyond certain basic characteristics that many philosophers agree about to explain what is seen as beautiful, the opinions are virtually endless. Nature and wildness have been important subjects in various eras of world history. An early tradition of landscape art began in China during the Tang Dynasty (618–907). The tradition of representing nature as it is became one of the aims of Chinese painting and was a significant influence in Asian art.
Although natural wonders are celebrated in the Psalms and the Book of Job, wilderness portrayals in art became more prevalent in the 1800s, especially in the works of the Romantic movement. British artists John Constable and J. M. W. Turner turned their attention to capturing the beauty of the natural world in their paintings. Before that, paintings had been primarily of religious scenes or of human beings. William Wordsworth's poetry described the wonder of the natural world, which had formerly been viewed as a threatening place. Increasingly the valuing of nature became an aspect of Western culture. This artistic movement also coincided with the Transcendentalist movement in the Western world. A common classical idea of beautiful art involves the word mimesis, the imitation of nature. Also in the realm of ideas about beauty in nature is that the perfect is implied through perfect mathematical forms and more generally by patterns in nature. As David Rothenburg writes, "The beautiful is the root of science and the goal of art, the highest possibility that humanity can ever hope to see".:281
Some fields of science see nature as matter in motion, obeying certain laws of nature which science seeks to understand. For this reason the most fundamental science is generally understood to be "physics"—the name for which is still recognizable as meaning that it is the study of nature.
Matter is commonly defined as the substance of which physical objects are composed. It constitutes the observable universe. The visible components of the universe are now believed to compose only 4.9 percent of the total mass. The remainder is believed to consist of 26.8 percent cold dark matter and 68.3 percent dark energy. The exact arrangement of these components is still unknown and is under intensive investigation by physicists.
The behavior of matter and energy throughout the observable universe appears to follow well-defined physical laws. These laws have been employed to produce cosmological models that successfully explain the structure and the evolution of the universe we can observe. The mathematical expressions of the laws of physics employ a set of twenty physical constants that appear to be static across the observable universe. The values of these constants have been carefully measured, but the reason for their specific values remains a mystery.
Outer space, also simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. Outer space is used to distinguish it from airspace (and terrestrial locations). There is no discrete boundary between the Earth's atmosphere and space, as the atmosphere gradually attenuates with increasing altitude. Outer space within the Solar System is called interplanetary space, which passes over into interstellar space at what is known as the heliopause.
Outer space is sparsely filled with several dozen types of organic molecules discovered to date by microwave spectroscopy, blackbody radiation left over from the big bang and the origin of the universe, and cosmic rays, which include ionized atomic nuclei and various subatomic particles. There is also some gas, plasma and dust, and small meteors. Additionally, there are signs of human life in outer space today, such as material left over from previous manned and unmanned launches which are a potential hazard to spacecraft. Some of this debris re-enters the atmosphere periodically.
Although the Earth is the only body within the solar system known to support life, evidence suggests that in the distant past the planet Mars possessed bodies of liquid water on the surface. For a brief period in Mars' history, it may have also been capable of forming life. At present though, most of the water remaining on Mars is frozen. If life exists at all on Mars, it is most likely to be located underground where liquid water can still exist.
Conditions on the other terrestrial planets, Mercury and Venus, appear to be too harsh to support life as we know it. But it has been conjectured that Europa, the fourth-largest moon of Jupiter, may possess a sub-surface ocean of liquid water and could potentially host life.
[a Lake is] any relatively large body of slowly moving or standing water that occupies an inland basin of appreciable size. Definitions that precisely distinguish lakes, ponds, swamps, and even rivers and other bodies of nonoceanic water are not well established. It may be said, however, that rivers and streams are relatively fast moving; marshes and swamps contain relatively large quantities of grasses, trees, or shrubs; and ponds are relatively small in comparison to lakes. Geologically defined, lakes are temporary bodies of water.
|archive-date=(help)., which takes global average weight as 60 kg.), the total human biomass is the average weight multiplied by the current human population of approximately 6.5 billion (see, e.g., "World Population Information". U.S. Census Bureau. Retrieved September 28, 2006.): Assuming 60–70 kg to be the average human mass (approximately 130–150 lb on the average), an approximation of total global human mass of between 390 billion (390×109) and 455 billion kg (between 845 billion and 975 billion lb, or about 423 million–488 million short tons). The total biomass of all kinds on earth is estimated to be in excess of 6.8 x 1013 kg (75 billion short tons). By these calculations, the portion of total biomass accounted for by humans would be very roughly 0.6%.
Aliaune Damala Badara Akon Thiam (; born April 16, 1973) is an American singer, songwriter, record producer, entrepreneur, philanthropist and actor. He rose to prominence in 2004 following the release of "Locked Up", the first single from his debut album, Trouble.
He has since founded two successful record labels, Konvict Muzik and KonLive Distribution. The labels served as a stepping stone for many soon-to-be successful acts, most notably Lady Gaga, T-Pain, R. City, Kardinall Offishall and Red Café, among others. His second album, Konvicted received three nominations for the Grammy Awards in two categories, Best Contemporary R&B Album for Konvicted album and Best Rap/Sung Collaboration for "Smack That" and "I Wanna Love You".
He is the first solo artist to hold both the number one and two spots simultaneously on the Billboard Hot 100 charts twice. Akon has had four songs certified as 3× platinum, three songs certified as 2× platinum, more than ten songs certified as 1× platinum and more than ten songs certified as gold in digital sales. Akon has sung songs in other languages including Tamil, Hindi, and Spanish. He was listed by the Guinness Book of World Records as the #1 selling artist for master ringtones in the world.
Akon often provides vocals as a featured artist and is currently credited with over 300 guest appearances and more than 35 Billboard Hot 100 songs, resulting to five Grammy Awards nominations. He has released 6 solo albums, and has handled the majority of production on his solo work and guest features. Alongside this, he also produced records mainly for artists on his respective labels, as well as for other artists such as Michael Jackson, Snoop Dogg, Lionel Richie, Leona Lewis, Sean Paul and Whitney Houston.
Forbes ranked Akon 80th (Power Rank) in Forbes Celebrity 100 in 2010 and 5th in 40 Most Powerful Celebrities in Africa list, in 2011. Billboard ranked Akon No. 6 on the list of Top Digital Songs Artists of the decade.Critically endangered
A critically endangered (CR) species is one that has been categorized by the International Union for Conservation of Nature (IUCN) as facing an extremely high risk of extinction in the wild.As of 2014, there are 2,464 animal and 2,104 plant species with this assessment.As the IUCN Red List does not consider a species extinct until extensive, targeted surveys have been conducted, species that are possibly extinct are still listed as critically endangered. IUCN maintains a list of "possibly extinct" CR(PE) and "possibly extinct in the wild" CR(PEW) species, modelled on categories used by BirdLife International to categorize these taxa.God
In monotheistic thought, God is conceived of as the supreme being, creator deity, and principal object of faith. The conceptions of God, as described by theologians, commonly include the attributes of omniscience (all-knowing), omnipotence (all-powerful), omnipresence (all-present), and as having an eternal and necessary existence. Depending on one's kind of theism, these attributes are used either in way of analogy, or in a literal sense as distinct properties. God is most often held to be incorporeal (immaterial). Incorporeality and corporeality of God are related to conceptions of transcendence (being outside nature) and immanence (being in nature) of God, with positions of synthesis such as the "immanent transcendence". Psychoanalyst Carl Jung equated religious ideas of God with transcendental aspects of consciousness in his interpretation.Some religions describe God without reference to gender, while others or their translations use sex-specific terminology. Judaism attributes only a grammatical gender to God, using terms such as "Him" or "Father" for convenience.God has been conceived as either personal or impersonal. In theism, God is the creator and sustainer of the universe, while in deism, God is the creator, but not the sustainer, of the universe. In pantheism, God is the universe itself. In atheism, there is an absence of belief in God. In agnosticism, the existence of God is deemed unknown or unknowable. God has also been conceived as the source of all moral obligation, and the "greatest conceivable existent". Many notable philosophers have developed arguments for and against the existence of God.Monotheists refer to their gods using names prescribed by their respective religions, with some of these names referring to certain cultural ideas about their god's identity and attributes. In the ancient Egyptian era of Atenism, possibly the earliest recorded monotheistic religion, this deity was called Aten, premised on being the one "true" Supreme Being and creator of the universe. In the Hebrew Bible and Judaism, Elohim, Adonai, YHWH (Hebrew: יהוה) and other names are used as the names of God. Yahweh and Jehovah, possible vocalizations of YHWH, are used in Christianity. In the Christian doctrine of the Trinity, God, coexisting in three "persons", is called the Father, the Son, and the Holy Spirit. In Islam, the name Allah is used, while Muslims also have a multitude of titular names for God. In Hinduism, Brahman is often considered a monistic concept of God. In Chinese religion, Shangdi is conceived as the progenitor (first ancestor) of the universe, intrinsic to it and constantly bringing order to it. Other religions have names for the concept, for instance, Baha in the Bahá'í Faith, Waheguru in Sikhism, Sang Hyang Widhi Wasa in Balinese Hinduism, and Ahura Mazda in Zoroastrianism.The many different conceptions of God, and competing claims as to God's characteristics, aims, and actions, have led to the development of ideas of omnitheism, pandeism, or a perennial philosophy, which postulates that there is one underlying theological truth, of which all religions express a partial understanding, and as to which "the devout in the various great world religions are in fact worshipping that one God, but through different, overlapping concepts".IUCN Red List
The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1965, has evolved to become the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red List are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
The IUCN Red List is set upon precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. The aim is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to try to reduce species extinction. According to the International Union for Conservation of Nature (IUCN) (1996), the formally stated goals of the Red List are (1) to provide scientifically based information on the status of species and subspecies at a global level, (2) to draw attention to the magnitude and importance of threatened biodiversity, (3) to influence national and international policy and decision-making, and (4) to provide information to guide actions to conserve biological diversity.Major species assessors include BirdLife International, the Institute of Zoology (the research division of the Zoological Society of London), the World Conservation Monitoring Centre, and many Specialist Groups within the IUCN Species Survival Commission (SSC). Collectively, assessments by these organizations and groups account for nearly half the species on the Red List.
The IUCN aims to have the category of every species re-evaluated every five years if possible, or at least every ten years. This is done in a peer reviewed manner through IUCN Species Survival Commission (SSC) Specialist Groups, which are Red List Authorities responsible for a species, group of species or specific geographic area, or in the case of BirdLife International, an entire class (Aves).As of 2018, 26,197 species are now classified as vulnerable, critical or endangered.Impact factor
The impact factor (IF) or journal impact factor (JIF) of an academic journal is a measure reflecting the yearly average number of citations to recent articles published in that journal. It is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factors are often deemed to be more important than those with lower ones. The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for journals listed in the Journal Citation Reports.International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable".
Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. Unlike many other international environmental organisations, IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice, and through building partnerships. The organization is best known to the wider public for compiling and publishing the IUCN Red List of Threatened Species, which assesses the conservation status of species worldwide.IUCN has a membership of over 1400 governmental and non-governmental organizations. Some 16,000 scientists and experts participate in the work of IUCN commissions on a voluntary basis. It employs approximately 1000 full-time staff in more than 50 countries. Its headquarters are in Gland, Switzerland.IUCN has observer and consultative status at the United Nations, and plays a role in the implementation of several international conventions on nature conservation and biodiversity. It was involved in establishing the World Wide Fund for Nature and the World Conservation Monitoring Centre. In the past, IUCN has been criticized for placing the interests of nature over those of indigenous peoples. In recent years, its closer relations with the business sector have caused controversy.IUCN was established in 1948. It was previously called the International Union for the Protection of Nature (1948–1956) and the World Conservation Union (1990–2008).Macmillan Publishers
Macmillan Publishers Ltd (occasionally known as the Macmillan Group) is an international publishing company owned by Holtzbrinck Publishing Group. It has offices in 41 countries worldwide and operates in more than thirty others.Natural law
Natural law (Latin: ius naturale, lex naturalis) is a philosophy asserting that certain rights are inherent by virtue of human nature, endowed by nature—traditionally by God or a transcendent source—and that these can be understood universally through human reason. As determined by nature, the law of nature is implied to be objective and universal; it exists independently of human understanding, and of the positive law of a given state, political order, legislature or society at large.
Historically, natural law refers to the use of reason to analyze human nature to deduce binding rules of moral behavior from nature's or God's creation of reality and mankind. The concept of natural law was documented in ancient Greek philosophy, including Aristotle, and was referred to in Roman philosophy by Cicero. References to natural law are also found in the Old and New Testaments of the Bible, later expounded upon in the Middle Ages by Christian philosophers such as Albert the Great and Thomas Aquinas. The School of Salamanca made notable contributions during the Renaissance. Modern natural law theories were greatly developed in the Age of Enlightenment, combining inspiration from Roman law with philosophies like social contract theory. Key proponents were Alberico Gentili, Francisco Suárez, Richard Hooker, Thomas Hobbes, Hugo Grotius, Samuel von Pufendorf, Matthew Hale, John Locke, Francis Hutcheson, Jean Jacques Burlamaqui, Emmerich de Vattel, Cesare Beccaria and Francesco Mario Pagano. It was used to challenge the divine right of kings, and became an alternative justification for the establishment of a social contract, positive law, and government—and thus legal rights—in the form of classical republicanism. Conversely, the concept of natural rights is used by others to challenge the legitimacy of all such establishments.
Contemporarily, the concept of natural law is closely related to the concept of natural rights. Indeed, many philosophers, jurists and scholars use natural law synonymously with natural rights (Latin: ius naturale), or natural justice. while others distinguish between natural law and natural right.Because of the intersection between natural law and natural rights, natural law has been claimed or attributed as a key component in the United States Declaration of Independence (1776), the Declaration of the Rights of Man and of the Citizen (1789) of France, the Universal Declaration of Human Rights (1948) of the United Nations General Assembly, as well as the European Convention on Human Rights (1953) of the European Union.Nature (journal)
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869. It is one of the most recognizable scientific journals in the world, and was ranked the world's most cited scientific journal by the Science Edition of the 2010 Journal Citation Reports and is ascribed an impact factor of 40.137, making it one of the world's top academic journals. It is one of the few remaining academic journals that publishes original research across a wide range of scientific fields.Research scientists are the primary audience for the journal, but summaries and accompanying articles are intended to make many of the most important papers understandable to scientists in other fields and the educated public. Towards the front of each issue are editorials, news and feature articles on issues of general interest to scientists, including current affairs, science funding, business, scientific ethics and research breakthroughs. There are also sections on books, arts, and short science fiction stories. The remainder of the journal consists mostly of research papers (articles or letters), which are often dense and highly technical. Because of strict limits on the length of papers, often the printed text is actually a summary of the work in question with many details relegated to accompanying supplementary material on the journal's website.
There are many fields of research in which important new advances and original research are published as either articles or letters in Nature. The papers that have been published in this journal are internationally acclaimed for maintaining high research standards. Fewer than 8% of submitted papers are accepted for publication.In 2007 Nature (together with Science) received the Prince of Asturias Award for Communications and Humanity.Nature reserve
A nature reserve (also known as natural reserve, bioreserve, natural/nature preserve, or natural/nature conserve) is a protected area of importance for flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research. Nature reserves may be designated by government institutions in some countries, or by private landowners, such as charities and research institutions, regardless of nationality. Nature reserves fall into different IUCN categories depending on the level of protection afforded by local laws. Normally it is more strictly protected than a nature park.Nature versus nurture
The nature versus nurture debate involves whether human behavior is determined by the environment, either prenatal or during a person's life, or by a person's genes. The alliterative expression "nature and nurture" in English has been in use since at least the Elizabethan period and goes back to medieval French.The combination of the two concepts as complementary is ancient (Greek: ἁπό φύσεως καὶ εὐτροφίας). Nature is what we think of as pre-wiring and is influenced by genetic inheritance and other biological factors. Nurture is generally taken as the influence of external factors after conception e.g. the product of exposure, experience and learning on an individual.The phrase in its modern sense was popularized by the English Victorian polymath Francis Galton, the modern founder of eugenics and behavioral genetics, discussing the influence of heredity and environment on social advancement. Galton was influenced by the book On the Origin of Species written by his half-cousin, Charles Darwin.
The view that humans acquire all or almost all their behavioral traits from "nurture" was termed tabula rasa ("blank slate") by John Locke in 1690. A "blank slate view" in human developmental psychology assuming that human behavioral traits develop almost exclusively from environmental influences, was widely held during much of the 20th century (sometimes termed "blank-slatism").
The debate between "blank-slate" denial of the influence of heritability, and the view admitting both environmental and heritable traits, has often been cast in terms of nature versus nurture. These two conflicting approaches to human development were at the core of an ideological dispute over research agendas throughout the second half of the 20th century. As both "nature" and "nurture" factors were found to contribute substantially, often in an inextricable manner, such views were seen as naive or outdated by most scholars of human development by the 2000s.The strong dichotomy of nature versus nurture has thus been claimed to have limited relevance in some fields of research. Close feedback loops have been found in which "nature" and "nurture" influence one another constantly, as seen in self-domestication. In ecology and behavioral genetics, researchers think nurture has an essential influence on nature. Similarly in other fields, the dividing line between an inherited and an acquired trait becomes unclear, as in epigenetics or fetal development.Paganism
Paganism (from classical Latin pāgānus "rural, rustic", later "civilian"), is a term first used in the fourth century by early Christians for people in the Roman Empire who practiced polytheism. This was either because they were increasingly rural and provincial relative to the Christian population, or because they were not milites Christi (soldiers of Christ). Alternate terms in Christian texts for the same group were hellene, gentile, and heathen. Ritual sacrifice was an integral part of ancient Graeco-Roman religion and was regarded as an indication of whether a person was pagan or Christian.Paganism was originally a pejorative and derogatory term for polytheism, implying its inferiority. Paganism has broadly connoted the "religion of the peasantry", During and after the Middle Ages, the term paganism was applied to any non-Abrahamic or unfamiliar religion, and the term presumed a belief in false god(s). Most modern pagan religions existing today - Modern Paganism, or Neopaganism -
express a world view that is pantheistic, polytheistic or animistic; but some are monotheistic.The origin of the application of the term pagan to polytheism is debated. In the 19th century, paganism was adopted as a self-descriptor by members of various artistic groups inspired by the ancient world. In the 20th century, it came to be applied as a self-descriptor by practitioners of Modern Paganism, Neopagan movements and Polytheistic reconstructionists. Modern pagan traditions often incorporate beliefs or practices, such as nature worship, that are different from those in the largest world religions.Contemporary knowledge of old pagan religions comes from several sources, including anthropological field research records, the evidence of archaeological artifacts, and the historical accounts of ancient writers regarding cultures known to Classical antiquity.Philosophy
Philosophy (from Greek φιλοσοφία, philosophia, literally "love of wisdom") is the study of general and fundamental questions about existence, knowledge, values, reason, mind, and language. Such questions are often posed as problems to be studied or resolved. The term was probably coined by Pythagoras (c. 570 – 495 BCE). Philosophical methods include questioning, critical discussion, rational argument, and systematic presentation. Classic philosophical questions include: Is it possible to know anything and to prove it? What is most real? Philosophers also pose more practical and concrete questions such as: Is there a best way to live? Is it better to be just or unjust (if one can get away with it)? Do humans have free will?Historically, "philosophy" encompassed any body of knowledge. From the time of Ancient Greek philosopher Aristotle to the 19th century, "natural philosophy" encompassed astronomy, medicine, and physics. For example, Newton's 1687 Mathematical Principles of Natural Philosophy later became classified as a book of physics. In the 19th century, the growth of modern research universities led academic philosophy and other disciplines to professionalize and specialize. In the modern era, some investigations that were traditionally part of philosophy became separate academic disciplines, including psychology, sociology, linguistics, and economics.
Other investigations closely related to art, science, politics, or other pursuits remained part of philosophy. For example, is beauty objective or subjective? Are there many scientific methods or just one? Is political utopia a hopeful dream or hopeless fantasy? Major sub-fields of academic philosophy include metaphysics ("concerned with the fundamental nature of reality and being"), epistemology (about the "nature and grounds of knowledge [and]...its limits and validity"), ethics, aesthetics, political philosophy, logic and philosophy of science.Ric Flair
Richard Morgan Fliehr (born February 25, 1949), better known as Ric Flair, is an American professional wrestling manager and retired professional wrestler signed to WWE under its Legends program.
Ranked by multiple peers and journalists as the greatest professional wrestler of all time, Flair had a career that spanned 40 years. He is noted for his tenures with Jim Crockett Promotions (JCP), World Championship Wrestling (WCW), the World Wrestling Federation (WWF, later WWE) and Total Nonstop Action Wrestling (TNA). Since the mid-1970s, he has used the moniker "The Nature Boy". A major pay-per-view attraction throughout his career, Flair headlined at the premier annual NWA/WCW event, Starrcade, on ten occasions, while also co-headlining its WWF counterpart, WrestleMania, in 1992, after winning that year's Royal Rumble. PWI awarded him their Wrestler of the Year award a record six times, while Wrestling Observer Newsletter named him the Wrestler of the Year (an award named after him and Lou Thesz) a record eight times. The first two-time WWE Hall of Fame inductee, first inducted with the class of 2008 for his individual career and again with the class of 2012 as a member of The Four Horsemen, he is also a member of the NWA Hall of Fame, Professional Wrestling Hall of Fame, and Wrestling Observer Newsletter Hall of Fame.
Flair is officially recognized by WWE as a 16-time world champion (eight-time NWA World Heavyweight Champion, six-time WCW World Heavyweight Champion, and two-time WWF Champion), although the number of his world championship reigns varies by source, ranging from 16 to 25. He has claimed to be a 21-time champion. He was the first holder of the WCW World Heavyweight Championship and the WCW International World Heavyweight Championship (which he also held last). As the inaugural WCW World Heavyweight Champion, he became the first person to complete WCW's Triple Crown, having already held the United States Heavyweight and World Tag Team Championships. He then completed WWE's version of the Triple Crown when he won the Intercontinental Championship, after already holding the WWF Championship and the World Tag Team Championship.Science
Science (from the Latin word scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3500 to 3000 BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to explain events of the physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages but was preserved in the Muslim world during the Islamic Golden Age. The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived natural philosophy, which was later transformed by the Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions. The scientific method soon played a greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape.Modern science is typically divided into three major branches that consist of the natural sciences (e.g., biology, chemistry, and physics), which study nature in the broadest sense; the social sciences (e.g., economics, psychology, and sociology), which study individuals and societies; and the formal sciences (e.g., logic, mathematics, and theoretical computer science), which study abstract concepts. There is disagreement, however, on whether the formal sciences actually constitute a science as they do not rely on empirical evidence. Disciplines that use existing scientific knowledge for practical purposes, such as engineering and medicine, are described as applied sciences.Science is based on research, which is commonly conducted in academic and research institutions as well as in government agencies and companies. The practical impact of scientific research has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the development of commercial products, armaments, health care, and environmental protection.Stoicism
Stoicism is a school of Hellenistic philosophy founded by Zeno of Citium in Athens in the early 3rd century BC. While Stoic physics are largely drawn from the teachings of the philosopher Heraclitus, they are heavily influenced by certain teachings of Socrates. Stoicism is predominantly a philosophy of personal ethics informed by its system of logic and its views on the natural world. According to its teachings, as social beings, the path to happiness for humans is found in accepting the moment as it presents itself, by not allowing oneself to be controlled by the desire for pleasure or fear of pain, by using one's mind to understand the world and to do one's part in nature's plan, and by working together and treating others fairly and justly.
The Stoics are especially known for teaching that "virtue is the only good" for human beings, and that external things—such as health, wealth, and pleasure—are not good or bad in themselves, but have value as "material for virtue to act upon". Alongside Aristotelian ethics, the Stoic tradition forms one of the major founding approaches to Western virtue ethics. The Stoics also held that certain destructive emotions resulted from errors of judgment, and they believed people should aim to maintain a will (called prohairesis) that is "in accord with nature". Because of this, the Stoics thought the best indication of an individual's philosophy was not what a person said, but how a person behaved. To live a good life, one had to understand the rules of the natural order since they thought everything was rooted in nature.
Many Stoics—such as Seneca and Epictetus—emphasized that because "virtue is sufficient for happiness", a sage would be emotionally resilient to misfortune. This belief is similar to the meaning of the phrase "stoic calm", though the phrase does not include the "radical ethical" Stoic views that only a sage can be considered truly free, and that all moral corruptions are equally vicious.Stoicism flourished throughout the Roman and Greek world until the 3rd century AD, and among its adherents was Emperor Marcus Aurelius. It experienced a decline after Christianity became the state religion in the 4th century AD. Since then it has seen revivals, notably in the Renaissance (Neostoicism) and in the contemporary era (modern Stoicism).Supernatural
The concept of the supernatural encompasses anything that is inexplicable by scientific understanding of the laws of nature but nevertheless argued by believers to exist. Examples include immaterial beings such as angels, gods and spirits, and claimed human abilities like magic, telekinesis and extrasensory perception.
Historically, supernatural entities have been invoked to explain phenomena as diverse as lightning, seasons and the human senses. Naturalists maintain that nothing beyond the physical world exists and hence maintain skeptical attitudes towards supernatural concepts.The supernatural is featured in paranormal, occult and religious contexts, but can also feature as an explanation in more secular contexts.The Wealth of Nations
An Inquiry into the Nature and Causes of the Wealth of Nations, generally referred to by its shortened title The Wealth of Nations, is the magnum opus of the Scottish economist and moral philosopher Adam Smith. First published in 1776, the book offers one of the world's first collected descriptions of what builds nations' wealth, and is today a fundamental work in classical economics. By reflecting upon the economics at the beginning of the Industrial Revolution, the book touches upon such broad topics as the division of labour, productivity, and free markets.World Wide Fund for Nature
The World Wide Fund for Nature (WWF) is an international non-governmental organization founded in 1961, working in the field of the 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, supporting around 1,300 conservation and environmental projects. They have invested over $1 billion in more than 12,000 conservation initiatives since 1995. WWF is a foundation with 55% of funding from individuals and bequests, 19% from government sources (such as the World Bank, DFID, USAID) and 8% from corporations in 2014.WWF aims to "stop the degradation of the planet's natural environment and to build a future in which humans live in harmony with nature." The Living Planet Report is published every two years by WWF since 1998; it is based on a Living Planet Index and ecological footprint calculation. In addition, WWF has launched several notable worldwide campaigns including Earth Hour and Debt-for-Nature Swap, and its current work is organized around these six areas: food, climate, freshwater, wildlife, forests, and oceans.WWF has been accused by BuzzFeed News, Kathmandu Post, the Rainforest Foundation Fund and Survival International of protecting paramilitary forces funded by the organization to fight poaching that have engaged in human rights abuses despite an internal report acknowledging them in 2015. They have attacked African and South Asian villages, torturing, raping, and killing villagers. Investigators also revealed that the WWF actively engaged in cover ups and lobbied to release rangers when they were arrested.