FACTOID # 12: It's not the government they hate: Washington DC has the highest number of hate crimes per capita in the US.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Carbon cycle
Diagram of the carbon cycle. The black numbers indicate how much carbon is stored in various reservoirs, in billions of tons ("GtC" stands for GigaTons of Carbon and figures are circa 2004). The purple numbers indicate how much carbon moves between reservoirs each year. The sediments, as defined in this diagram, do not include the ~70 million GtC of carbonate rock and kerogen
Diagram of the carbon cycle. The black numbers indicate how much carbon is stored in various reservoirs, in billions of tons ("GtC" stands for GigaTons of Carbon and figures are circa 2004). The purple numbers indicate how much carbon moves between reservoirs each year. The sediments, as defined in this diagram, do not include the ~70 million GtC of carbonate rock and kerogen

The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere, and atmosphere of the Earth. This article does not cite its references or sources. ... Image File history File links Carbon_cycle-cute_diagram. ... Image File history File links Carbon_cycle-cute_diagram. ... In ecology, a biogeochemical cycle is a circuit where a nutrient moves back and forth between both biotic and abiotic components of ecosystems. ... For other uses, see Carbon (disambiguation). ... A false-color composite of global oceanic and terrestrial photoautotroph abundance, from September 1997 to August 2000. ... In the most general sense, the geosphere is the region of space that is dominated by geogenic matter (originating from and bound to the Earth). ... The movement of water around, over, and through the Earth is called the water cycle, a key process of the hydrosphere. ... “Air” redirects here. ... This article is about Earth as a planet. ...


The cycle is usually thought of as four major reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, the terrestrial biosphere (which usually includes freshwater systems and non-living organic material, such as soil carbon), the oceans (which includes dissolved inorganic carbon and living and non-living marine biota), and the sediments (which includes fossil fuels). The annual movements of carbon, the carbon exchanges between reservoirs, occur because of various chemical, physical, geological, and biological processes. The ocean contains the largest active pool of carbon near the surface of the Earth, but the deep ocean part of this pool does not rapidly exchange with the atmosphere. Animated map exhibiting the worlds oceanic waters. ... The total inorganic carbon (CT, or TIC)is the sum of inorganic carbon species in a solution. ... This article or section cites very few or no references or sources. ... Fossil fuels are hydrocarbons, primarily coal and petroleum (fuel oil or natural gas), formed from the fossilized remains of dead plants and animals[1] by exposure to heat and pressure in the Earths crust over hundreds of millions of years[2]. The theory that hydrocarbons were formed from these... The deep ocean is the lowest layer in an ocean, existing below the thermocline. ...


The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere - biosphere) of the carbon cycle. An examination of the carbon budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide to happen.

Contents

In the atmosphere

Carbon exists in the Earth's atmosphere primarily as the gas carbon dioxide (CO2). Although it is a very small part of the atmosphere overall (approximately 0.04% on a molar basis, though rising), it plays an important role in supporting life. Other gases containing carbon in the atmosphere are methane and chlorofluorocarbons (the latter is entirely anthropogenic). The overall atmospheric concentration of these greenhouse gases has been increasing in recent decades, contributing to global warming.[1] “Air” redirects here. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... The mole (symbol: mol) is the SI base unit that measures an amount of substance. ... Methane is a chemical compound with the molecular formula CH4. ... For other uses, see CFC (disambiguation). ... Look up anthropogenic in Wiktionary, the free dictionary. ... Top: Increasing atmospheric CO2 levels as measured in the atmosphere and ice cores. ... Global mean surface temperatures 1850 to 2006 Mean surface temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980 Global warming is the observed increase in the average temperature of the Earths atmosphere and oceans in recent decades and the projected...


Carbon is taken from the atmosphere in several ways:

  • When the sun is shining, plants perform photosynthesis to convert carbon dioxide into carbohydrates, releasing oxygen in the process. This process is most prolific in relatively new forests where tree growth is still rapid.
  • At the surface of the oceans towards the poles, seawater becomes cooler and more carbonic acid is formed as CO2 becomes more soluble. This is coupled to the ocean's thermohaline circulation which transports dense surface water into the ocean's interior (see the entry on the solubility pump).
  • In upper ocean areas of high biological productivity, organisms convert reduced carbon to tissues, or carbonates to hard body parts such as shells and tests. These are, respectively, oxidized (soft-tissue pump) and redissolved (carbonate pump) at lower average levels of the ocean than those at which they formed, resulting in a downward flow of carbon (see entry on the biological pump).
  • The weathering of silicate rock. Carbonic acid reacts with weathered rock to produce bicarbonate ions. The bicarbonate ions produced are carried to the ocean, where they are used to make marine carbonates. Unlike dissolved CO2 in equilibrium or tissues which decay, weathering does not move the carbon into a reservoir from which it can readily return to the atmosphere.

Carbon can be released back into the atmosphere in many different ways, For other uses, see Plant (disambiguation). ... The leaf is the primary site of photosynthesis in plants. ... Carbohydrates (literally hydrates of carbon) are chemical compounds that act as the primary biological means of storing or consuming energy, other forms being fat and protein. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... Annual mean sea surface salinity for the World Ocean. ... Carbonic acid (ancient name acid of air or aerial acid) has the formula H2CO3. ... A simplified summary of the path of the Thermohaline Circulation. ... In oceanic biogeochemistry, the solubility pump is a physico-chemical process that transports carbon (as dissolved inorganic carbon) from the oceans surface to its interior. ... In oceanic biogeochemistry, the biological pump is the sum of a suite of biologically-mediated processes that transport carbon from the surface euphotic zone to the oceans interior. ... For baking soda, see Sodium bicarbonate In inorganic chemistry, a bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. ...

  • Through the respiration performed by plants and animals. This is an exothermic reaction and it involves the breaking down of glucose (or other organic molecules) into carbon dioxide and water.
  • Through the decay of animal and plant matter. Fungi and bacteria break down the carbon compounds in dead animals and plants and convert the carbon to carbon dioxide if oxygen is present, or methane if not.
  • Through combustion of organic material which oxidizes the carbon it contains, producing carbon dioxide (and other things, like water vapor). Burning fossil fuels such as coal, petroleum products, and natural gas releases carbon that has been stored in the geosphere for millions of years.
  • Production of cement. Carbon dioxide is released when limestone (calcium carbonate) is heated to produce lime (calcium oxide), a component of cement.
  • At the surface of the oceans where the water becomes warmer, dissolved carbon dioxide is released back into the atmosphere
  • Volcanic eruptions and metamorphism release gases into the atmosphere. These gases include water vapor, carbon dioxide and sulfur dioxide. The carbon dioxide released is roughly equal to the amount removed by silicate weathering; so the two processes, which are the chemical reverse of each other, sum to roughly zero, and do not affect the level of atmospheric carbon dioxide on time scales of less than about 100,000 yr.

In chemistry, an exothermic reaction is one that releases heat . ... Divisions Chytridiomycota Zygomycota Ascomycota Basidiomycota The Fungi (singular: fungus) are a large group of organisms ranked as a kingdom within the Domain Eukaryota. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Methane is a chemical compound with the molecular formula CH4. ... A combustion reaction taking place in a igniting match Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames. ... The most fundamental reactions in chemistry are the redox processes. ... Fossil fuels are hydrocarbons, primarily coal and petroleum (fuel oil or natural gas), formed from the fossilized remains of dead plants and animals[1] by exposure to heat and pressure in the Earths crust over hundreds of millions of years[2]. The theory that hydrocarbons were formed from these... Coal Coal (IPA: ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... Pumpjack pumping an oil well near Lubbock, Texas Ignacy Łukasiewicz - inventor of the refining of kerosene from crude oil. ... For other uses, see Natural gas (disambiguation). ... In the most general sense of the word, cement is a binder, a substance which sets and hardens independently, and can bind other materials together. ... For other uses, see Limestone (disambiguation). ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... It has been suggested that multiple sections of steam be merged into this article or section. ... Sulfur dioxide (or Sulphur dioxide) has the chemical formula SO2. ...

In the biosphere

Around 1,900 gigatons of carbon are present in the biosphere. Carbon is an essential part of life on Earth. It plays an important role in the structure, biochemistry, and nutrition of all living cells. A gigaton (or gigatonne) is a Metric Unit of mass, equal to 1,000,000,000 (1 billion) Metric tons, 1,000,000,000,000 (1 trillion) kilograms, or 1 quadrillion grams. ... The eukaryotic cytoskeleton. ... Biochemistry is the study of the chemical processes in living organisms. ... The updated USDA food pyramid, published in 2005, is a general nutrition guide for recommended food consumption for humans. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the...

  • Autotrophs are organisms that produce their own organic compounds using carbon dioxide from the air or water in which they live. To do this they require an external source of energy. Almost all autotrophs use solar radiation to provide this, and their production process is called photosynthesis. A small number of autotrophs exploit chemical energy sources in a process called chemosynthesis. The most important autotrophs for the carbon cycle are trees in forests on land and phytoplankton in the Earth's oceans. Photosynthesis follows the reaction 6CO2 + 6H2O → C6H12O6 + 6O2
  • Carbon is transferred within the biosphere as heterotrophs feed on other organisms or their parts (e.g., fruits). This includes the uptake of dead organic material (detritus) by fungi and bacteria for fermentation or decay.
  • Most carbon leaves the biosphere through respiration. When oxygen is present, aerobic respiration occurs, which releases carbon dioxide into the surrounding air or water, following the reaction C6H12O6 + 6O2 → 6CO2 + 6H2O. Otherwise, anaerobic respiration occurs and releases methane into the surrounding environment, which eventually makes its way into the atmosphere or hydrosphere (e.g., as marsh gas or flatulence).
  • Burning of biomass (e.g. forest fires, wood used for heating, anything else organic) can also transfer substantial amounts of carbon to the atmosphere
  • Carbon may also be circulated within the biosphere when dead organic matter (such as peat) becomes incorporated in the geosphere. Animal shells of calcium carbonate, in particular, may eventually become limestone through the process of sedimentation.
  • Much remains to be learned about the cycling of carbon in the deep ocean. For example, a recent discovery is that larvacean mucus houses (commonly known as "sinkers") are created in such large numbers that they can deliver as much carbon to the deep ocean as has been previously detected by sediment traps [1]. Because of their size and composition, these houses are rarely collected in such traps, so most biogeochemical analyses have erroneously ignored them.

Carbon storage in the biosphere is influenced by a number of processes on different time-scales: while net primary productivity follows a diurnal and seasonal cycle, carbon can be stored up to several hundreds of years in trees and up to thousands of years in soils. Changes in those long term carbon pools (e.g. through de- or afforestation or through temperature-related changes in soil respiration) will thus directly affect global warming. Green (from chlorophyll) fronds of a maidenhair fern: a photoautotroph Flowchart to determine if a species is autotroph, heterotroph, or a subtype An autotroph (from the Greek autos = self and trophe = nutrition) is an organism that produces complex organic compounds from simple inorganic molecules and an external source of energy... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... The leaf is the primary site of photosynthesis in plants. ... Chemosynthesis is the biological conversion of 1-carbon molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic molecules (e. ... The coniferous Coast Redwood, the tallest tree species on earth. ... Diagrams of some typical phytoplankton Phytoplankton are the autotrophic component of plankton. ... Flowchart to determine if a species is autotroph, heterotroph, or a subtype A heterotroph (Greek heterone = (an)other and trophe = nutrition) is an organism that requires organic substrates to get its carbon for growth and development. ... Detritus may refer to: In geology, detritus is the name for loose fragments of rock that have been worn away by erosion. ... It has been suggested that this article or section be merged with Fermentation (food). ... This page may meet Wikipedias criteria for speedy deletion. ... Cellular respiration describes the metabolism reactions and processes that take place in a cell to obtain biochemical energy from fuel molecules. ... This article or section should be merged with aerobic metabolism. ... Anaerobic respiration refers to the oxidation of molecules in the absence of oxygen to produce energy, in opposition to Aerobic respiration which does use oxygen. ... Flatulence (expelled through the anus in a process commonly known as farting or emitting gas) is the presence of a mixture of gases known as flatus in the digestive tract of mammals. ... Peat in Lewis, Scotland Peat is an accumulation of partially decayed vegetation matter. ... Various seashells Danielle A shell is the hard, rigid outer covering, or integument, allanimals. ... Calcium carbonate is a chemical compound, with the chemical formula CaCO3. ... For other uses, see Limestone (disambiguation). ... This article or section cites very few or no references or sources. ... Families Fritillariidae Kowalevskiidae Oikopleuridae The Appendicularia or Larvacea are a group of free-swimming pelagic urochordates found throughout the worlds oceans. ... Mucus is a slippery secretion of the lining of various membranes in the body. ... Sediment traps are instruments used in oceanography to measure the quantity of sinking particulate organic (and inorganic) material in aquatic systems, usually oceans. ... Global oceanic and terrestrial photoautotroph abundance, from September 1997 to August 2000. ...


In the oceans

"Present day" (1990s) sea surface dissolved inorganic carbon concentration (from the GLODAP climatology)

The seas contain around 36,000 gigatonnes of carbon, mostly in the form of bicarbonate ion. Inorganic carbon, that is carbon compounds with no carbon-carbon or carbon-hydrogen bonds, is important in its reactions within water. This carbon exchange becomes important in controlling pH in the ocean and can also vary as a source or sink for carbon. Carbon is readily exchanged between the atmosphere and ocean. In regions of oceanic upwelling, carbon is released to the atmosphere. Conversely, regions of downwelling transfer carbon (CO2) from the atmosphere to the ocean. When CO2 enters the ocean, carbonic acid is formed: Image File history File links Download high-resolution version (1658x1133, 289 KB) Annual mean sea surface dissolved inorganic carbon concentration for the present day (1990s) from the Global Ocean Data Analysis Project climatology. ... Image File history File links Download high-resolution version (1658x1133, 289 KB) Annual mean sea surface dissolved inorganic carbon concentration for the present day (1990s) from the Global Ocean Data Analysis Project climatology. ... For the band, see 1990s (band). ... The total inorganic carbon (CT, or TIC)is the sum of inorganic carbon species in a solution. ... The Global Ocean Data Analysis Project (GLODAP) is a synthesis project bringing together oceanographic data collected during the 1990s by research cruises on the World Ocean Circulation Experiment (WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. ... Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time,[1] and is a branch of the atmospheric sciences. ... A gigaton (or gigatonne) is a metric unit of mass, equal to 1,000,000,000 (1 billion) metric tons, 1,000,000,000,000 (1 trillion) kilograms, or 1 quadrillion grams. ... For other uses, see PH (disambiguation). ...

CO2 + H2O H2CO3

This reaction has a forward and reverse rate, that is it achieves a chemical equilibrium. Another reaction important in controlling oceanic pH levels is the release of hydrogen ions and bicarbonate. This reaction controls large changes in pH: Apparatus for carrying out acid-base titration. ...

H2CO3 H+ + HCO3

Carbon cycle modeling

Models of the carbon cycle can be incorporated into global climate models, so that the interactive response of the oceans and biosphere on future CO2 levels can be modelled. There are considerable uncertainties in this, both in the physical and biogeochemical submodels (especially the latter). Such models typically show that there is a positive feedback between temperature and CO2. For example, Zeng et al. (GRL, 2004 [2]) find that in their model, including a coupled carbon cycle increases atmospheric CO2 by about 90 ppmv at 2100 (over that predicted in models with non-interactive carbon cycles), leading to an extra 0.6°C of warming (which, in turn, may lead to even greater atmospheric CO2). General Circulation Models (GCMs) are a class of computer-driven models for weather forecasting and predicting climate change, where they are commonly called Global Climate Models. ...


See also

C4MIP (more fully, Coupled Carbon Cycle Climate Model Intercomparison Project) is a joint project between IGBP-GAIM and WCRP-WGCM. It is a model intercomparison project along the lines of AMIP, but for carbon cycle models inside global climate models . ... Change in sea surface pH caused by anthropogenic CO2 between the 1700s and the 1990s Ocean acidification is the name given to the ongoing decrease in the pH of the Earths oceans, caused by their uptake of anthropogenic carbon dioxide from the atmosphere. ... Global oceanic and terrestrial photoautotroph abundance, from September 1997 to August 2000. ... Per capita greenhouse gas emissions A carbon footprint is the total amount of CO2 and other greenhouse gases emitted over the full life cycle of a product or service. ...

References

  • SCOPE 13 The Global Carbon Cycle [3]
  • Janzen, H. H. (2004). Carbon cycling in earth systems — a soil science perspective. In Agriculture, ecosystems and environment, 104, 399 – 417.
  • Houghton, R. A. (2005). The contemporary carbon cycle. Pages 473-513 in W. H. Schlesinger, editor. Biogeochemistry. Elsevier Science.
  1. ^ The Intergovernmental Panel on Climate Change (IPCC) which represents a wide consensus of international scientific opinion.

External links

Biogeochemical cycles
Carbon cycle - Hydrogen cycle - Nitrogen cycle
Oxygen cycle - Phosphorus cycle - Sulfur cycle - Water cycle

  Results from FactBites:
 
carbon cycle: Definition and Much More from Answers.com (5360 words)
The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.
Carbon exists in the Earth's atmosphere primarily as the gas carbon dioxide (CO Although it is a very small part of the atmosphere overall (approximately 0.04% on a molar basis, though rising), it plays an important role in supporting life.
Carbon storage in the biosphere is influenced by a number of processes on different time-scales: while Net primary productivity follows a diurnal and seasonal cycle, carbon can be stored up to several hundreds of years in trees and up to thousands of years in soils.
Ch 7. Carbon Cycle (1821 words)
Carbon's electron structure gives it a plus 4 charge, which means that it can readily form bonds with itself, leading to a great diversity in the chemical compounds that can be formed around carbon; hence the diversity and complexity of life.
Carbon occurs in many other forms and places on Earth; it is a major constituent of limestones, occurring as calcium carbonate; it is dissolved in ocean water and fresh water; and it is present in the atmosphere as carbon dioxide, the second most important greenhouse gas.
The global carbon cycle is currently the topic of great interest because of its importance in the global climate system and also because human activities are altering the carbon cycle to a significant degree.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m