"Natural force" redirects here. For the music album, seeNatural Force.
Land management has preserved the natural characteristics ofHopetoun Falls,Australia while allowing ample access for visitors.An image of theSahara Desert from satellite. It is the world's largest hot desert and third-largest desert after thepolar deserts.
Thenatural environment ornatural world encompasses allbiotic andabiotic things occurringnaturally, meaning in this case notartificial. The term is most often applied toEarth or some parts of Earth. This environment encompasses the interaction of all livingspecies,climate, weather and natural resources that affect human survival and economic activity.[1]The concept of thenatural environment can be distinguished as components:
Completeecological units that function as natural systems without massive civilized human intervention, including all vegetation,microorganisms,soil,rocks, plateaus, mountains, theatmosphere andnatural phenomena that occur within their boundaries and their nature.
In contrast to the natural environment is thebuilt environment. Built environments are where humans have fundamentally transformed landscapes such as urban settings and agriculturalland conversion, the natural environment is greatly changed into a simplified human environment. Even acts which seem less extreme, such as building a mudhut or aphotovoltaic system in thedesert, the modified environment becomes an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hencebeaver dams and the works ofmound-building termites are thought of as natural.
There are noabsolutely natural environments on Earth. Naturalness usually varies in a continuum, from 100% natural in one extreme to 0% natural in the other. The massive environmental changes of humanity in theAnthropocene have fundamentally affected all natural environments including:climate change,biodiversity loss andpollution from plastic andother chemicals in theair andwater. More precisely, we can consider the different aspects or components of an environment, and see that their degree of naturalness is not uniform.[2] If, for instance, we take an agricultural field, and consider themineralogic composition and thestructure of its soil, we will find that whereas the first is quite similar to that of an undisturbed forest soil, the structure is quite different.
Earth science generally recognizes four spheres, thelithosphere, thehydrosphere, theatmosphere and thebiosphere[3] as correspondent torocks,water,air andlife respectively. Some scientists include as part of the spheres of the Earth, thecryosphere (corresponding toice) as a distinct portion of the hydrosphere, as well as thepedosphere (tosoil) as an active and intermixed sphere. Earth science (also known as geoscience, the geographical sciences or the Earth Sciences), is an all-embracing term for thesciences related to the planetEarth.[4] There are four majordisciplines in earth sciences, namelygeography,geology,geophysics andgeodesy. These major disciplines usephysics,chemistry,biology,chronology andmathematics to build a qualitative and quantitative understanding of the principal areas orspheres of Earth.
TheEarth's crust orlithosphere, is the outermost solid surface of the planet and is chemically, physically and mechanically different from underlyingmantle. It has been generated greatly byigneous processes in whichmagma cools and solidifies to form solid rock. Beneath the lithosphere lies the mantle which is heated by thedecay ofradioactive elements. The mantle though solid is in a state ofrheicconvection. This convection process causes the lithospheric plates to move, albeit slowly. The resulting process is known asplate tectonics.Volcanoes result primarily from the melting ofsubducted crust material or of rising mantle atmid-ocean ridges andmantle plumes.
An ocean is a major body ofsaline water and a component of the hydrosphere. Approximately 71% of thesurface of the Earth (an area of some 362 million square kilometers) is covered by ocean, acontinuous body of water that is customarily divided into several principal oceans and smallerseas. More than half of this area is over 3,000 meters (9,800 ft) deep. Average oceanicsalinity is around 35parts 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 theWorld Ocean or global ocean.[5][6] The deepseabeds are more than half the Earth's surface, and are among the least-modified natural environments. The major oceanic divisions are defined in part by thecontinents, variousarchipelagos and other criteria, these divisions are, in descending order of size, thePacific Ocean, theAtlantic Ocean, theIndian Ocean, theSouthern Ocean and theArctic Ocean.
A river is a naturalwatercourse,[7] usuallyfreshwater, flowing toward anocean, alake, asea or another river. A few rivers simply flow into the ground and dry up completely without reaching another body of water.
The water in a river is usually in achannel, made up of astream bed betweenbanks. In larger rivers there is often also a widerfloodplain shaped by waters over-topping the channel. Flood plains may be very wide in relation to the size of the river channel. Rivers are a part of thehydrological cycle. Water within a river is generally collected fromprecipitation throughsurface runoff,groundwater recharge,springs and the release of water stored inglaciers and snowpacks.
Small rivers may also be called by several other names, includingstream, creek and brook. Theircurrent is confined within abed andstream banks. Streams play an importantcorridor role in connectingfragmented habitats and thus in conservingbiodiversity. The study of streams and waterways in general is known assurfacehydrology.[8]
A lake (from Latinlacus) is aterrain feature, a body of water that is localized to the bottom ofbasin. A body of water is considered a lake when it is inland, is not part of anocean and is larger and deeper than apond.[9][10]
Natural lakes on Earth are generally found inmountainous areas,rift zones and areas with ongoing or recentglaciation. Other lakes are found inendorheic 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 thelast 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 abody ofstanding water, either natural or human-made, that is usually smaller than alake. A wide variety of human-made bodies of water are classified as ponds, includingwater gardens designed for aesthetic ornamentation,fish ponds designed for commercial fish breeding andsolar ponds designed to store thermal energy. Ponds and lakes are distinguished from streams by theircurrent 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 asstream pools andtide pools.
Humans impact the water in different ways such as modifying rivers (throughdams andstream channelization),urbanization anddeforestation. These impact lake levels, groundwater conditions,water pollution,thermal pollution, andmarine pollution. Humans modify rivers by using direct channel manipulation.[11] We build dams and reservoirs and manipulate the direction of the rivers and water path. Dams can usefully create reservoirs and hydroelectric power. However, reservoirs and dams may negatively impact the environment and wildlife. Dams stop fish migration and the movement of organisms downstream. Urbanization affects the environment because of deforestation and changing lake levels, groundwater conditions, etc. Deforestation and urbanization go hand in hand. Deforestation may cause flooding, declining stream flow and changes in riverside vegetation. The changing vegetation occurs because when trees cannot get adequate water they start to deteriorate, leading to a decreased food supply for the wildlife in an area.[11]
Theozone layer of the Earth's atmosphere plays an important role in reducing the amount ofultraviolet (UV) radiation that reaches the surface. AsDNA 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.
Earth's atmosphere can be divided into five main layers. These layers are mainly determined by whether temperature increases or decreases with altitude. From highest to lowest, these layers are:
Exosphere: The outermost layer of Earth's atmosphere extends from the exobase upward, mainly composed ofhydrogen andhelium.
Thermosphere: The top of the thermosphere is the bottom of the exosphere, called theexobase. Its height varies with solar activity and ranges from about 350–800 km (220–500 mi; 1,150,000–2,620,000 ft). TheInternational Space Station orbits in this layer, between 320 and 380 km (200 and 240 mi). In another way, the thermosphere is Earth's second highest atmospheric layer, extending from approximately 260,000 feet at the mesopause to the thermopause at altitudes ranging from 1,600,000 to 3,300,000 feet.[14]
Mesosphere: The mesosphere extends from the stratopause to 80–85 km (50–53 mi; 262,000–279,000 ft). It is the layer where mostmeteors burn up upon entering the atmosphere.[15][16]
Stratosphere: The stratosphere extends from the tropopause to about 51 km (32 mi; 167,000 ft). Thestratopause, which is the boundary between the stratosphere and mesosphere, typically is at 50 to 55 km (31 to 34 mi; 164,000 to 180,000 ft).
Troposphere: The troposphere begins at the surface and extends to between 7 km (23,000 ft) at the poles and 17 km (56,000 ft) at the equator, with some variation due to weather. The troposphere is mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest and temperature decreases with altitude. Thetropopause is the boundary between the troposphere and stratosphere.
Other layers
Within the five principal layers determined by temperature there are several layers determined by other properties.
Theozone layer is contained within the stratosphere. It is mainly located in the lower portion of the stratosphere from about 15–35 km (9.3–21.7 mi; 49,000–115,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in our atmosphere is contained in the stratosphere.
Theionosphere: The part of the atmosphere that is ionized by solar radiation, stretches from 50 to 1,000 km (31 to 621 mi; 160,000 to 3,280,000 ft) and typically overlaps both the exosphere and the thermosphere. It forms the inner edge of the magnetosphere.
Thehomosphere andheterosphere: The homosphere includes the troposphere, stratosphere and mesosphere. The upper part of the heterosphere is composed almost completely of hydrogen, the lightest element.
The dangers ofglobal warming are being increasingly studied by a wide global consortium of scientists.[17] These scientists are increasingly concerned about the potentiallong-term effects of global warming on our natural environment and on the planet. Of particular concern is howclimate change and global warming caused byanthropogenic, or human-made releases ofgreenhouse gases, most notablycarbon dioxide, can act interactively and have adverse effects upon the planet, its natural environment and humans' existence. It is clear the planet is warming, and warming rapidly. This is due to thegreenhouse effect, which is caused by greenhouse gases, which trap heat inside the Earth's atmosphere because of their more complex molecular structure which allows them to vibrate and in turn trap heat and release it back towards the Earth.[18] This warming is also responsible for the extinction of natural habitats, which in turn leads to a reduction in wildlife population. The most recent report from theIntergovernmental Panel on Climate Change (the group of the leading climate scientists in the world) concluded that the earth will warm anywhere from 2.7 to almost 11 degrees Fahrenheit (1.5 to 6 degrees Celsius) between 1990 and 2100.[19]Efforts have been increasingly focused on themitigation of greenhouse gases that are causing climatic changes, ondeveloping adaptative strategies to global warming, to assist humans, other animal, and plant species, ecosystems, regions andnations in adjusting to theeffects of global warming. Some examples of recent collaboration toaddress climate change and global warming include:
TheKyoto Protocol, which is the protocol to the international Framework Convention on Climate Change treaty, again with the objective of reducing greenhouse gases in an effort to prevent anthropogenic climate change.[21]
TheWestern Climate Initiative, to identify, evaluate, and implement collective and cooperative ways to reduce greenhouse gases in the region, focusing on a market-basedcap-and-trade system.[22]
A significantly profound challenge is to identify the natural environmental dynamics in contrast to environmental changes not within natural variances. A common solution is to adapt a static view neglecting natural variances to exist. Methodologically, this view could be defended when looking at processes which change slowly and short time series, while the problem arrives when fast processes turns essential in the object of the study.
Climates can beclassified according to the average and typical ranges of different variables, most commonly temperature and precipitation. The most commonly used classification scheme is the one originally developed byWladimir Köppen. TheThornthwaite system,[24] in use since 1948, usesevapotranspiration as well as temperature and precipitation information to study animal species diversity and the potential impacts ofclimate changes.[25]
Weather is a set of all thephenomena occurring in a givenatmospheric area at a giventime.[26] Most weather phenomena occur in thetroposphere,[27][28] just below thestratosphere.Weather refers, generally, to day-to-day temperature and precipitation activity, whereasclimate is the term for the average atmospheric conditions over longer periods of time.[29] When used without qualification,weather is understood to be the weather of Earth.
Weather occurs due to density (temperature and moisture) differences between one place and another. These differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics. The strong temperature contrast between polar and tropical air gives rise to thejet stream. Weather systems in themid-latitudes, such asextratropical cyclones, are caused by instabilities of the jet stream flow. Because the Earth'saxis is tilted relative to its orbital plane,sunlight is incident at different angles at different times of the year. On the Earth's surface, temperatures usually range ±40 °C (100 °F to −40 °F) annually. Over thousands of years, changes in the Earth's orbit have affected the amount and distribution of solar energy received by the Earth and influenced long-term climate.
Surfacetemperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes due to differences incompressional heating.Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. The atmosphere is achaotic system, and small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts tocontrol the weather have occurred throughout human history, and there is evidence that civilized human activity such asagriculture andindustry has inadvertently modified weather patterns.
Evidence suggests thatlife on Earth has existed for about 3.7billion years.[30] All known life forms share fundamental molecular mechanisms, and based on these observations, theories on theorigin of life attempt to find a mechanism explaining the formation of a primordial single cell organism from which all life originates. There are many different hypotheses regarding the path that might have been taken from simpleorganic molecules via pre-cellular life to protocells and metabolism.
Although there is no universal agreement on the definition of life, scientists generally accept that the biological manifestation of life is characterized byorganization,metabolism,growth,adaptation, response tostimuli andreproduction.[31] Life may also be said to be simply the characteristic state oforganisms. Inbiology, the science of living organisms, "life" is the condition which distinguishes activeorganisms frominorganic matter, including the capacity for growth,functional activity and the continual change preceding death.[32][33]
A diverse variety of living organisms (life forms) can be found in thebiosphere on Earth, and properties common to these organisms—plants,animals,fungi,protists,archaea, andbacteria—are acarbon- and water-basedcellular form with complexorganization and heritablegenetic information. Living organisms undergometabolism, maintainhomeostasis, possess a capacity togrow, respond tostimuli,reproduce and, throughnatural selection, adapt to their environment in successive generations. More complex living organisms can communicate through various means.
Anecosystem (also called an environment) is a natural unit consisting of all plants, animals, and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical (abiotic) factors of the environment.[34]
Central to the ecosystem concept is the idea thatliving organisms are continually engaged in a highly interrelated set of relationships with every other element constituting theenvironment in which they exist.Eugene Odum, one of the founders of the science ofecology, stated: "Any unit that includes all of the organisms (i.e.: 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."[35]
The human ecosystem concept is then grounded in the deconstruction of the human/naturedichotomy, and the emergent premise that all species are ecologically integrated with each other, as well as with the abiotic constituents of theirbiotope.
A more significant number or variety of species orbiological diversity of an ecosystem may contribute to greater resilience of an ecosystem because there are more species present at a location to respond to change and thus "absorb" or reduce its effects. This reduces the effect before the ecosystem's structure changes to a different state. This is not universally the case and there is no proven relationship between the species diversity of an ecosystem and its ability to provide goods and services on a sustainable level.
The termecosystem can also pertain to human-made environments, such ashuman ecosystems and human-influenced ecosystems. It can describe any situation where there is relationship between living organisms and their environment. Fewer areas on the surface of the earth today exist free from human contact, although some genuinewilderness areas continue to exist without any forms of human intervention.
Thenitrogen cycle is the transformation of nitrogen and nitrogen-containing compounds in nature. It is a cycle which includes gaseous components.
Thewater cycle, is the continuous movement of water on, above, and below the surface of the Earth. Water can change states among liquid, vapour, and ice at various places in the water cycle. Although the balance of water on Earth remains fairly constant over time, individual water molecules can come and go.
Thecarbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
Theoxygen cycle is the movement of oxygen within and between its three main reservoirs: the atmosphere, the biosphere, and thelithosphere. The main driving factor of the oxygen cycle isphotosynthesis, which is responsible for the modern Earth's atmospheric composition and life.
Thephosphorus cycle is the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. The atmosphere does not play a significant role in the movements of phosphorus, because phosphorus and phosphorus compounds are usually solids at the typical ranges of temperature and pressure found on Earth.
Wilderness is generally defined as a natural environment on Earth that has not been significantly modified byhuman activity. TheWILD Foundation goes into more detail, defining wilderness as: "The most intact, undisturbed wild natural areas left on our planet – those last truly wild places that humans do not control and have not developed with roads, pipelines or other industrial infrastructure."[37] Wilderness areas and protectedparks are considered important for the survival of certainspecies, ecological studies,conservation, solitude, andrecreation. Wilderness is deeply valued for cultural, spiritual,moral, andaesthetic reasons. Some nature writers believe wilderness areas are vital for the human spirit and creativity.[38]
The word, "wilderness", derives from the notion ofwildness; in other words that which is not controllable by humans. The wordetymology is from theOld Englishwildeornes, which in turn derives fromwildeor meaningwild beast (wild + deor = beast, deer).[39] From this point of view, it is the wildness of a place that makes it a wilderness. The mere presence or activity of people does not disqualify an area from being "wilderness". Many ecosystems that are, or have been, inhabited or influenced by activities of people may still be considered "wild". This way of looking at wilderness includes areas within which natural processes operate without very noticeable human interference.
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative. Wildlife can be found in all ecosystems. Deserts, rain forests, plains, and other areas—including the most developedurban sites—all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by civilized human factors, most scientists agree that wildlife around the world is (now) impacted by human activities.
It is the common understanding ofnatural environment that underliesenvironmentalism—a broadpolitical,social andphilosophical movement that advocates various actions and policies in the interest of protecting what nature remains in the natural environment, or restoring or expanding the role of nature in this environment. While true wilderness is increasingly rare,wild nature (e.g., unmanagedforests, uncultivatedgrasslands,wildlife,wildflowers) can be found in many locations previously inhabited by humans.
Halting human-inducedglobal warming, which represents pollution, a threat to biodiversity, and a threat to human populations.
Shifting fromfossil fuels torenewable energy in electricity, heating and cooling, and transportation, which addresses pollution, global warming, and sustainability. This may includepublic transportation anddistributed generation, which have benefits for traffic congestion and electric reliability.
In some cultures the term environment is meaningless because there is no separation between people and what they view as the natural world, or their surroundings.[48] Specifically in the United States and Arabian countries many native cultures do not recognize the "environment", or see themselves as environmentalists.[49]
^Johnson, D. L.; Ambrose, S. H.; Bassett, T. J.; Bowen, M. L.; Crummey, D. E.; Isaacson, J. S.; Johnson, D. N.; Lamb, P.; Saul, M.; Winter-Nelson, A. E. (1997). "Meanings of Environmental Terms".Journal of Environmental Quality.26 (3):581–589.Bibcode:1997JEnvQ..26..581J.doi:10.2134/jeq1997.00472425002600030002x.
^Britannica Online."Lake (physical feature)".Archived from the original on 11 June 2008. Retrieved25 June 2008.[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 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.
^"Dictionary.com definition".Archived from the original on 17 June 2008. Retrieved25 June 2008.a body of fresh or salt water of considerable size, surrounded by land.
^Joe Buchdahl."Trace Gases".Encyclopedia of the Atmospheric Environment. Atmosphere, Climate & Environment Information Programme. Archived fromthe original on 9 October 2010. Retrieved9 March 2013.
^Speight, James G. (2020). "Water systems".Natural Water Remediation. pp. 1–51.doi:10.1016/B978-0-12-803810-9.00001-2.ISBN978-0-12-803810-9.The thermosphere is the second-highest layer of the atmosphere and extends from the mesopause (which separates it from the mesosphere) at an altitude of approximately 260,000 ft up to the thermopause at an altitude that ranges from 1,600,000 to 3,300,000 ft.
^Speight, James G. (2017). "Chemicals and the Environment".Environmental Organic Chemistry for Engineers. pp. 1–41.doi:10.1016/B978-0-12-804492-6.00001-0.ISBN978-0-12-804492-6.The mesosphere is the third highest layer of atmosphere and occupies the region above the stratosphere and below the thermosphere. This layer extends from the stratopause at an altitude of approximately 160,000 ft to the mesopause at approximately 260,000–80,000 ft above sea level. ...The mesosphere is also the layer where most meteors burn up upon atmospheric entrance.
^Jamieson, Dale. (2007). "The Heart of Environmentalism". In R. Sandler & P. C. Pezzullo.Environmental Justice and Environmentalism. Massachusetts Institute of Technology Press. pp. 85–101.ISBN9780262195522
^Davis, T. (2000).Sustaining the Forest, the People, and the Spirit. State University of New York. pp. 1–24.ISBN9780791444153
Adams, Simon; David Lambert (2006).Earth Science: An illustrated guide to science. New York NY 10001: Chelsea House. p. 20.ISBN0-8160-6164-5.{{cite book}}: CS1 maint: location (link)
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"Earth's Energy Budget". Oklahoma Climatological Survey. 1996–2004. Retrieved17 November 2007.
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Smith, Gary A.; Aurora Pun (2006).How Does the Earth Work? Physical Geologyand the Process of Science. Upper Saddle River, NJ 07458: Pearson Prentice Hall. p. 5.ISBN0-13-034129-0.{{cite book}}: CS1 maint: location (link)
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