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81-425: Dot Earth is a media piece environmental blog , by science writer Andrew Revkin , which ran from 2007 to 2016 for The New York Times . The blog's aim is to examine efforts to balance human affairs with the planet's limits. Featuring videos, interviews and other types of information like environmental and climate change issues, including energy policy, conservation, biodiversity , and sustainability, Dot Earth

162-556: A blog , vlog , or other Internet publication is a stub . You can help Misplaced Pages by expanding it . This article about climate change is a stub . You can help Misplaced Pages by expanding it . See guidelines for writing about climate change . Further suggestions might be found on the article's talk page . Environment (biophysical) In contrast to the natural environment is the built environment . Built environments are where humans have fundamentally transformed landscapes such as urban settings and agricultural land conversion ,

243-441: A capacity to grow , respond to stimuli , reproduce and, through natural selection , adapt to their environment in successive generations. More complex living organisms can communicate through various means. An ecosystem (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

324-425: A chemistry that reflects the type of reactions that take place in the soil. The primary conditions for soil development are controlled by the chemical composition of the rock on which the soil will be. Rock types that form the base of the soil profile are often either sedimentary (carbonate or siliceous), igneous or metaigneous ( metamorphosed igneous rocks) or volcanic and metavolcanic rocks. The rock type and

405-502: A continuum, from 100% natural in one extreme to 0% natural in the other. The massive environmental changes of humanity in the Anthropocene have fundamentally effected all natural environments including: climate change , biodiversity loss and pollution from plastic and other chemicals in the air and water . More precisely, we can consider the different aspects or components of an environment, and see that their degree of naturalness

486-637: A decreased food supply for the wildlife in an area. The atmosphere of the Earth serves as a key factor in sustaining the planetary ecosystem. The thin layer of gases that envelops the Earth is held in place by the planet's gravity. Dry air consists of 78% nitrogen , 21% oxygen , 1% argon , inert gases and carbon dioxide . The remaining gases are often referred to as trace gases. The atmosphere includes greenhouse gases such as carbon dioxide, methane, nitrous oxide and ozone. Filtered air includes trace amounts of many other chemical compounds . Air also contains

567-442: A freelancer, with the move being done to make clear the line between the two categories. After 9 years and 2,810 posts, Revkin ended the blog on 5 December 2016, just before he began work as a senior reporter for ProPublica . According to a Pace University press release, an institution in which the blogger is associated, the blog is "read by millions of people in over 200 countries, from Brazil to China". This article about

648-402: A layer known as caliche . Deserts behave similarly to grasslands but operate in constant drought as precipitation is less than evapotranspiration. Chemical weathering proceeds more slowly than in grasslands and beneath the caliche layer may be a layer of gypsum and halite . To study soils in deserts, pedologists have used the concept of chronosequences to relate the timing and development of

729-454: A pond from many other aquatic terrain features, such as stream pools and tide pools . Humans impact the water in different ways such as modifying rivers (through dams and stream channelization ), urbanization and deforestation . These impact lake levels, groundwater conditions, water pollution, thermal pollution, and marine pollution . Humans modify rivers by using direct channel manipulation. We build dams and reservoirs and manipulate

810-400: A qualitative and quantitative understanding of the principal areas or spheres of Earth. The Earth's crust or lithosphere , is the outermost solid surface of the planet and is chemically, physically and mechanically different from underlying mantle . It has been generated greatly by igneous processes in which magma cools and solidifies to form solid rock. Beneath the lithosphere lies

891-430: A river is usually in a channel , made up of a stream bed between banks . In larger rivers there is often also a wider floodplain 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 the hydrological cycle . Water within a river is generally collected from precipitation through surface runoff , groundwater recharge , springs and

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972-588: A study was done on Permian through Triassic rocks (300–200 million years old) in Japan and British Columbia. The geologists found hematite throughout the early and middle Permian but began to find the reduced form of iron in pyrite within the ancient soils near the end of the Permian and into the Triassic. These results suggest that conditions became less oxygen rich, even anoxic, during the late Permian, which eventually led to

1053-507: A variable amount of water vapor and suspensions of water droplets and ice crystals seen as clouds . Many natural substances may be present in tiny amounts in an unfiltered air sample, including dust , pollen and spores , sea spray , volcanic ash and meteoroids . Various industrial pollutants also may be present, such as chlorine (elementary or in compounds), fluorine compounds, elemental mercury , and sulphur compounds such as sulphur dioxide (SO 2 ). The ozone layer of

1134-542: A wide variety of aerosol particles, biological particles like pollen, and dust particles. Nitrogen is the most abundant constituent in rain (after water), as water vapor utilizes aerosol particles to nucleate rain droplets. Soil is well developed in the forest as suggested by the thick humus layers, rich diversity of large trees and animals that live there. Forest soils can form a thick soil carbon sponge. In forests, precipitation exceeds evapotranspiration which results in an excess of water that percolates downward through

1215-436: Is a terrain feature , a body of water that is localized to the bottom of basin . A body of water is considered a lake when it is inland, is not part of an ocean and is larger and deeper than a pond . 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

1296-516: 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. The deep seabeds 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

1377-635: Is carried on by the pioneer lichens and their successors, the mosses, in which the hair-like rhizoids assume the role of roots in breaking down the surface into fine dust. However, lichens are not necessarily the only pioneering organisms nor the earliest form of soil formation as it has been documented that seed-bearing plants may occupy an area and colonize quicker than lichen. Also, eolian sedimentation (wind generated) can produce high rates of sediment accumulation. Nonetheless, lichen can certainly withstand harsher conditions than most vascular plants, and although they have slower colonization rates, they do form

1458-406: Is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere , atmosphere , hydrosphere and biosphere . The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere (air in and above the soil), biosphere (living organisms), lithosphere (unconsolidated regolith and consolidated bedrock ) and

1539-544: Is extremely productive leading to the production of as much as 800 grams of carbon per square meter per year (8 tons of C/hectare/year). Higher temperatures and larger amounts of water contribute to higher rates of chemical weathering. Increased rates of decomposition cause smaller amounts of fulvic acid to percolate and leach metals from the zone of active weathering. Thus, in stark contrast to soil in temperate forests, tropical forests have little to no podzolization and therefore do not have marked visual and chemical contrasts with

1620-455: Is found in various kinds of natural body of water . An ocean is a major body of saline water and a component of the hydrosphere. Approximately 71% of the surface of the Earth (an area of some 362 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 ft) deep. Average oceanic salinity

1701-785: Is from the Old English wildeornes , which in turn derives from wildeor meaning wild beast (wild + deor = beast, deer). 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

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1782-440: Is in the system. The oxidizing environment accepts electrons because of the presence of O 2 , which acts as an electron acceptor: This equation will tend to move to the right in acidic conditions. Higher redox potentials are found at lower pH levels. Bacteria, heterotrophic organisms, consume oxygen while decomposing organic material. This depletes the soils of oxygen, thus decreasing the redox potential. At high redox potential,

1863-440: Is increasingly rare, wild nature (e.g., unmanaged forests , uncultivated grasslands , wildlife , wildflowers ) can be found in many locations previously inhabited by humans. Goals for the benefit of people and natural systems, commonly expressed by environmental scientists and environmentalists include: In some cultures the term environment is meaningless because there is no separation between people and what they view as

1944-443: Is not uniform. If, for instance, in an agricultural field, the mineralogic composition and the structure of its soil are similar to those of an undisturbed forest soil, but the structure is quite different. Earth science generally recognizes four spheres, the lithosphere , the hydrosphere , the atmosphere and the biosphere as correspondent to rocks , water , air and life respectively. Some scientists include as part of

2025-404: Is reduced. In a system, it will likely donate electrons to a part that has a low concentration of electrons, or an oxidized environment, to equilibrate to the chemical gradient. An oxidized environment has high redox potential, whereas a reduced environment has a low redox potential. The redox potential is controlled by the oxidation state of the chemical species, pH and the amount of O 2 there

2106-671: 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 a chaotic system , and small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts to control the weather have occurred throughout human history, and there is evidence that civilized human activity such as agriculture and industry has inadvertently modified weather patterns. Evidence suggests that life on Earth has existed for about 3.7 billion years. All known life forms share fundamental molecular mechanisms, and based on these observations, theories on

2187-430: Is the one originally developed by Wladimir Köppen . The Thornthwaite system , in use since 1948, uses evapotranspiration as well as temperature and precipitation information to study animal species diversity and the potential impacts of climate changes . Weather is a set of all the phenomena occurring in a given atmospheric area at a given time . Most weather phenomena occur in the troposphere , just below

2268-742: 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 . A river is a natural watercourse , usually freshwater , flowing toward an ocean , a lake , a sea or another river. A few rivers simply flow into the ground and dry up completely without reaching another body of water. The water in

2349-408: The mitigation of greenhouse gases that are causing climatic changes, on developing adaptative strategies to global warming, to assist humans, other animal, and plant species, ecosystems, regions and nations in adjusting to the effects of global warming . Some examples of recent collaboration to address climate change and global warming include: A significantly profound challenge is to identify

2430-486: The redox conditions of the environment. Inputs from the biosphere may begin with lichen and other microorganisms that secrete oxalic acid . These microorganisms, associated with the lichen community or independently inhabiting rocks, include blue-green algae , green algae , various fungi , and numerous bacteria. Lichen has long been viewed as the pioneers of soil development as the following 1997 Isozaki statement suggests: The initial conversion of rock into soil

2511-421: The stratosphere . Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate is the term for the average atmospheric conditions over longer periods of time. 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

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2592-518: The Earth's atmosphere plays an important role in reducing 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. 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: Within

2673-415: The abiotic constituents of their biotope . A more significant number or variety of species or biological 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

2754-482: The atmosphere. Carbonic acid is produced in the atmosphere and soil layers through the carbonation reaction. This is the dominant form of chemical weathering and aides in the breakdown of carbonate minerals (such as calcite and dolomite ) and silicate minerals (such as feldspar ). The breakdown of the Na-feldspar, albite , by carbonic acid to form kaolinite clay is as follows: Evidence of this reaction in

2835-421: The atmosphere. Methane is also released during the reduction of CO 2 by the same bacteria. In the pedosphere it is safe to assume that gases are in equilibrium with the atmosphere. Because plant roots and soil microbes release CO 2 to the soil, the concentration of bicarbonate ( HCO 3 ) in soil waters is much greater than that in equilibrium with the atmosphere, the high concentration of CO 2 and

2916-411: The bedrock where the biosphere and hydrosphere cease to make significant changes to the chemistry at depth. As part of the larger global system, any particular environment in which soil forms is influenced solely by its geographic position on the globe as climatic, geologic, biologic and anthropogenic changes occur with changes in longitude and latitude. The pedosphere lies below the vegetative cover of

2997-425: 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 . In biology , the science of living organisms, "life" is the condition which distinguishes active organisms from inorganic matter , including the capacity for growth, functional activity and

3078-605: The biosphere and above the hydrosphere and lithosphere. The soil forming process (pedogenesis) can begin without the aid of biology but is significantly quickened in the presence of biologic reactions, where it forms a soil carbon sponge . Soil formation begins with the chemical and/or physical breakdown of minerals to form the initial material that overlies the bedrock substrate. Biology quickens this by secreting acidic compounds that help break rock apart. Particular biologic pioneers are lichen , mosses and seed bearing plants, but many other inorganic reactions take place that diversify

3159-407: 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 term ecosystem can also pertain to human-made environments, such as human ecosystems and human-influenced ecosystems. It can describe any situation where there is relationship between living organisms and their environment. Fewer areas on

3240-420: The chemical makeup of the early soil layer. Once weathering and decomposition products accumulate, a coherent soil body allows the migration of fluids both vertically and laterally through the soil profile , causing ion exchange between solid, fluid and gaseous phases. As time progresses, the bulk geochemistry of the soil layer will deviate away from the initial composition of the bedrock and will evolve to

3321-425: The continual change preceding death. A diverse variety of living organisms (life forms) can be found in the biosphere on Earth, and properties common to these organisms—plants, animals , fungi , protists , archaea , and bacteria —are a carbon - and water-based cellular form with complex organization and heritable genetic information. Living organisms undergo metabolism , maintain homeostasis , possess

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3402-624: 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

3483-408: The dominant group in alpine regions . Organic acids released from plant roots include acetic acid and citric acid . During the decay of organic matter phenolic acids are released from plant matter and humic acid and fulvic acid are released by soil microbes. These organic acids speed up chemical weathering by combining with some of the weathering products in a process known as chelation . In

3564-572: The early soil profile. Oxidation of olivine (FeMgSiO 4 ) releases Fe, Mg and Si ions. The Mg is soluble in water and is carried in the runoff , but the Fe often reacts with oxygen to precipitate Fe 2 O 3 ( hematite ), the oxidized state of iron oxide. Sulfur , a byproduct of decaying organic material, will also react with iron to form pyrite (FeS 2 ) in reducing environments. Pyrite dissolution leads to low pH levels due to elevated H ions and further precipitation of Fe 2 O 3 ultimately changing

3645-409: The environment. Central to the ecosystem concept is the idea that living organisms are continually engaged in a highly interrelated set of relationships with every other element constituting the environment in which they exist. Eugene Odum , one of the founders of the science of ecology , stated: "Any unit that includes all of the organisms (i.e.: the "community") in a given area interacting with

3726-472: The extinction of natural habitats, which in turn leads to a reduction in wildlife population. The most recent report from the Intergovernmental 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. Efforts have been increasingly focused on

3807-408: The field would be elevated levels of bicarbonate ( HCO 3 ), sodium and silica ions in the water runoff. The breakdown of carbonate minerals: The further dissolution of carbonic acid (H 2 CO 3 ) and bicarbonate ( HCO 3 ) produces CO 2 gas. Oxidization is also a major contributor to the breakdown of many silicate minerals and formation of secondary minerals ( diagenesis ) in

3888-586: The five principal layers determined by temperature there are several layers determined by other properties. The dangers of global warming are being increasingly studied by a wide global consortium of scientists. These scientists are increasingly concerned about the potential long-term effects of global warming on our natural environment and on the planet. Of particular concern is how climate change and global warming caused by anthropogenic , or human-made releases of greenhouse gases , most notably carbon dioxide , can act interactively and have adverse effects upon

3969-497: The greatest extinction in Earth’s history, the P-T extinction . Decomposition in anoxic or reduced soils is also carried out by sulfur-reducing bacteria which, instead of O 2 use SO 4 as an electron acceptor and produce hydrogen sulfide (H 2 S) and carbon dioxide in the process: The H 2 S gas percolates upwards and reacts with Fe and precipitates pyrite, acting as a trap for

4050-521: The hydrosphere (water in, on and below the soil). The pedosphere is the foundation of terrestrial life on Earth. The pedosphere acts as the mediator of chemical and biogeochemical flux into and out of these respective systems and is made up of gaseous, mineralic, fluid and biologic components. The pedosphere lies within the Critical Zone, a broader interface that includes vegetation, pedosphere, aquifer systems, regolith and finally ends at some depth in

4131-415: The mantle which is heated by the decay of radioactive elements . The mantle though solid is in a state of rheic convection . This convection process causes the lithospheric plates to move, albeit slowly. The resulting process is known as plate tectonics . Volcanoes result primarily from the melting of subducted crust material or of rising mantle at mid-ocean ridges and mantle plumes . Most water

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4212-499: The mobilization of ions is more widespread. Rocks high in silica produce silicic acid as a weathering product. There are few rock types that lead to localized enrichment of some of the biologically limiting elements like phosphorus (P) and nitrogen (N). Phosphatic shale (< 15% P 2 O 5 ) and phosphorite (> 15% P 2 O 5 ) form in anoxic deep water basins that preserve organic material. Greenstone (metabasalt), phyllite , and schist release up to 30–50% of

4293-524: The natural environment is greatly changed into a simplified human environment. Even acts which seem less extreme, such as building a mud hut or a photovoltaic system in the desert , the modified environment becomes an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams and the works of mound-building termites are thought of as natural. People cannot find absolutely natural environments on Earth,naturalness usually varies in

4374-410: 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. Climate looks at

4455-469: The natural world, or their surroundings. Specifically in the United States and Arabian countries many native cultures do not recognize the "environment", or see themselves as environmentalists. Pedosphere The pedosphere (from Ancient Greek πέδον ( pédon )  'ground, earth' and σφαῖρα ( sphaîra )  'sphere') is the outermost layer of the Earth that

4536-475: The nitrogen pool. Thick successions of carbonate rocks are often deposited on craton margins during sea level rise. The widespread dissolution of carbonate and evaporites leads to elevated levels of Mg , HCO 3 , Sr , Na , Cl and SO 4 ions in aqueous solution. The process of soil formation is dominated by chemical weathering of silicate minerals, aided by acidic products of pioneering plants and organisms as well as carbonic acid inputs from

4617-462: The occurrence of metals in soil solutions results in lower pH levels in the soil. Gases that escape from the pedosphere to the atmosphere include the gaseous byproducts of carbonate dissolution, decomposition, redox reactions and microbial photosynthesis . The main inputs from the atmosphere are aeolian sedimentation, rainfall and gas diffusion. Eolian sedimentation includes anything that can be entrained by wind or that stays suspended in air and includes

4698-409: The origin 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 simple organic molecules via pre-cellular life to protocells and metabolism. Although there is no universal agreement on the definition of life, scientists generally accept that

4779-441: The oxidized form of iron, ferric iron (Fe ), will be deposited commonly as hematite . In low redox conditions, decomposition rates decrease and the deposition of ferrous iron (Fe ) increase. By using analytical geochemical tools such as X-ray fluorescence or inductively coupled mass spectrometry the two forms of Fe (Fe and Fe ) can be measured in ancient rocks therefore determining the redox potential for ancient soils. Such

4860-497: The pedosphere altering the course of soil evolution. Large mammalian herbivores above ground transport nutrients in form of nitrogen-rich waste and phosphorus-rich antlers, while predators leave phosphorus-rich piles of bones on the soil surface, leading to localized enrichment of the soil. Nutrient cycling in lakes and freshwater wetlands depends heavily on redox conditions. Under a few millimeters of water, heterotrophic bacteria metabolize and consume oxygen. They therefore deplete

4941-438: 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." The human ecosystem concept is then grounded in the deconstruction of the human/nature dichotomy , and the emergent premise that all species are ecologically integrated with each other, as well as with

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5022-400: 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 developed urban 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

5103-415: The planet, its natural environment and humans' existence. It is clear the planet is warming, and warming rapidly. This is due to the greenhouse 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. This warming is also responsible for

5184-488: The processes that lead to its exposure at the surface are controlled by the regional geologic setting of the specific area under study, which revolve around the underlying theory of plate tectonics , subsequent deformation , uplift , subsidence and deposition . Metaigneous and metavolcanic rocks form the largest component of cratons and are high in silica . Igneous and volcanic rocks are also high in silica, but with non-metamorphosed rock, weathering becomes faster and

5265-443: The release of water stored in glaciers and snowpacks. Small rivers may also be called by several other names, including stream , creek and brook. Their current is confined within a bed and stream banks . Streams play an important corridor role in connecting fragmented habitats and thus in conserving biodiversity . The study of streams and waterways in general is known as surface hydrology . A lake (from Latin lacus )

5346-468: The soil layers. Instead, the mobile metals Mg, Fe and Al are precipitated as oxide minerals giving the soil a rusty red color. Precipitation in grasslands is equal to or less than evapotranspiration and causes soil development to operate in relative drought. Leaching and migration of weathering products is therefore decreased. Large amounts of evaporation cause a buildup of calcium (Ca), and other large cations flocculate clay minerals and fulvic acids in

5427-593: The soil layers. Slow rates of decomposition leads to large amounts of fulvic acid , greatly enhancing chemical weathering. The downward percolation , in conjunction with chemical weathering leaches Mg, Fe, and aluminium (Al) from the soil and transports them downward, a process known as podzolization . This process leads to marked contrasts in the appearance and chemistry of the soil layers. Tropical forests receive more insolation and rainfall over longer growing seasons than any other environment on earth. With these elevated temperatures, insolation and rainfall, biomass

5508-426: The soil of oxygen and create the need for anaerobic respiration . Some anaerobic microbial processes include denitrification , sulfate reduction and methanogenesis and are responsible for the release of N 2 (nitrogen), H 2 S ( hydrogen sulfide ) and CH 4 ( methane ). Other anaerobic microbial processes are linked to changes in the oxidation state of iron and manganese. As a result of anaerobic decomposition,

5589-555: The soil profile, these organic acids are often concentrated at the top of the profile, while carbonic acid plays a larger role towards the bottom of the profile or below in the aquifer. As the soil column develops further into thicker accumulations, larger animals come to inhabit the soil and continue to alter the chemical evolution of their respective niche . Earthworms aerate the soil and convert large amounts of organic matter into rich humus , improving soil fertility . Small burrowing mammals store food, grow young and may hibernate in

5670-470: The soil stores large amounts of organic carbon because the soil carbon sponge stays intact. The reduction potential describes which way chemical reactions will proceed in oxygen deficient soils and controls the nutrient cycling in flooded systems. Reduction potential is used to express the likelihood of an environment to receive electrons and therefore become reduced. For example, if a system already has plenty of electrons (anoxic, organic-rich shale ) it

5751-627: The spheres of the Earth, the cryosphere (corresponding to ice ) as a distinct portion of the hydrosphere, as well as the pedosphere (to soil ) 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 the sciences related to the planet Earth . There are four major disciplines in earth sciences, namely geography , geology , geophysics and geodesy . These major disciplines use physics , chemistry , biology , chronology and mathematics to build

5832-495: The statistics of temperature , humidity , atmospheric pressure , wind , rainfall , atmospheric particle count and other meteorological elements in a given region over long periods of time. Weather , on the other hand, is the present condition of these same elements over periods up to two weeks. Climates can be classified according to the average and typical ranges of different variables, most commonly temperature and precipitation. The most commonly used classification scheme

5913-434: 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 the jet stream . Weather systems in the mid-latitudes , such as extratropical cyclones , are caused by instabilities of the jet stream flow. Because the Earth's axis is tilted relative to its orbital plane, sunlight is incident at different angles at different times of

5994-775: The surface of the earth today exist free from human contact, although some genuine wilderness areas continue to exist without any forms of human intervention. Global biogeochemical cycles are critical to life, most notably those of water , oxygen , carbon , nitrogen and phosphorus . Wilderness is generally defined as a natural environment on Earth that has not been significantly modified by human activity. The WILD 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." Wilderness areas and protected parks are considered important for

6075-420: The survival of certain species , ecological studies, conservation , solitude, and recreation . Wilderness is deeply valued for cultural, spiritual, moral , and aesthetic reasons. Some nature writers believe wilderness areas are vital for the human spirit and creativity. The word, "wilderness", derives from the notion of wildness ; in other words that which is not controllable by humans. The word etymology

6156-471: The toxic H 2 S gas. However, H 2 S is still a large fraction of emissions from wetland soils. In most freshwater wetlands there is little sulfate ( SO 4 ) so methanogenesis becomes the dominant form of decomposition by methanogenic bacteria only when sulfate is depleted. Acetate , a compound that is a byproduct of fermenting cellulose is split by methanogenic bacteria to produce methane (CH 4 ) and carbon dioxide (CO 2 ), which are released to

6237-409: The upper soil profile. Low amounts of precipitation and high levels of evapotranspiration limit the downward percolation of water and organic acids, reducing chemical weathering and soil development. The depth to the maximum concentration of clay increases in areas of increased precipitation and leaching. When leaching is decreased, the calcium precipitates as calcite (CaCO 3 ) in the lower soil levels,

6318-411: The world is (now) impacted by human activities. It is the common understanding of natural environment that underlies environmentalism — a broad political , social and philosophical 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

6399-826: 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 human-made, that is usually smaller than a lake . A wide variety of human-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 by their 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

6480-465: 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. Surface temperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes due to differences in compressional heating. Weather forecasting

6561-422: Was further described as "an interactive exploration of trends and ideas with readers and experts." Posted on October 25, 2007, Revkin's first entry on Dot Earth was on "Cutting Greenhouse Gases for Cash Prizes". In April 2010, "after 940 posts as a news blog", The New York Times moved Dot Earth to the "opinion side" of its online site. This decision accompanied Revkin's move from a fulltime position to that of

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