A report on Carbon cycle

Fast carbon cycle showing the movement of carbon between land, atmosphere, and oceans in billions of tons (gigatons) per year. Yellow numbers are natural fluxes, red are human contributions, white are stored carbon. The effects of the slow carbon cycle, such as volcanic and tectonic activity are not included.
Detail of anthropogenic carbon flows, showing cumulative mass in gigatons during years 1850-2018 (left) and the annual mass average during 2009-2018 (right).
CO2 concentrations over the last 800,000 years as measured from ice cores (blue/green) and directly (black)
Amount of carbon stored in Earth's various terrestrial ecosystems, in gigatonnes.
A portable soil respiration system measuring soil CO2 flux.
Diagram showing relative sizes (in gigatonnes) of the main storage pools of carbon on Earth. Cumulative changes (thru year 2014) from land use and emissions of fossil carbon are included for comparison.
Carbon is tetrahedrally bonded to oxygen
Knowledge about carbon in the core can be gained by analysing shear wave velocities
Schematic representation of the overall perturbation of the global carbon cycle caused by anthropogenic activities, averaged from 2010 to 2019.
The pathway by which plastics enter the world's oceans.
Carbon stored on land in vegetation and soils is aggregated into a single stock ct. Ocean mixed layer carbon, cm, is the only explicitly modelled ocean stock of carbon; though to estimate carbon cycle feedbacks the total ocean carbon is also calculated.
Epiphytes on electric wires. This kind of plant takes both CO{{sub|2}} and water from the atmosphere for living and growing.
CO{{sub|2}} in Earth's atmosphere if half of global-warming emissions are not absorbed.<ref name="NASA-20151112-ab" /><ref name="NASA-20151112b" /><ref name="NYT-20151110" /><ref name="AP-20151109" /> (NASA computer simulation).

Biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.

- Carbon cycle
Fast carbon cycle showing the movement of carbon between land, atmosphere, and oceans in billions of tons (gigatons) per year. Yellow numbers are natural fluxes, red are human contributions, white are stored carbon. The effects of the slow carbon cycle, such as volcanic and tectonic activity are not included.

30 related topics with Alpha

Overall

Estimated change in seawater pH caused by human-created carbon dioxide between the 1700s and the 1990s, from the Global Ocean Data Analysis Project (GLODAP) and the World Ocean Atlas

Ocean acidification

7 links

Ongoing decrease in the pH value of the Earth's oceans, caused by the uptake of carbon dioxide from the atmosphere.

Ongoing decrease in the pH value of the Earth's oceans, caused by the uptake of carbon dioxide from the atmosphere.

Estimated change in seawater pH caused by human-created carbon dioxide between the 1700s and the 1990s, from the Global Ocean Data Analysis Project (GLODAP) and the World Ocean Atlas
Here is a detailed image of the full carbon cycle
NOAA provides evidence for the upwelling of "acidified" water onto the Continental Shelf. In the figure above, note the vertical sections of (A) temperature, (B) aragonite saturation, (C) pH, (D) DIC, and (E) p on transect line 5 off Pt. St. George, California. The potential density surfaces are superimposed on the temperature section. The 26.2 potential density surface delineates the location of the first instance in which the undersaturated water is upwelled from depths of 150 to 200 m onto the shelf and outcropping at the surface near the coast. The red dots represent sample locations.
Ocean Acidification Infographic
The cycle between the atmosphere and the ocean
Distribution of (A) aragonite and (B) calcite saturation depth in the global oceans
This map shows changes in the aragonite saturation level of ocean surface waters between the 1880s and the most recent decade (2006–2015). Aragonite is a form of calcium carbonate that many marine animals use to build their skeletons and shells. The lower the saturation level, the more difficult it is for organisms to build and maintain their skeletons and shells. A negative change represents a decrease in saturation.
Here is detailed diagram of the carbon cycle within the ocean
Bjerrum plot: Change in carbonate system of seawater from ocean acidification.
Shells of pteropods dissolve in increasingly acidic conditions caused by increased amounts of atmospheric
A normally-protective shell made thin, fragile and transparent by acidification
Drivers of hypoxia and ocean acidification intensification in upwelling shelf systems. Equatorward winds drive the upwelling of low dissolved oxygen (DO), high nutrient, and high dissolved inorganic carbon (DIC) water from above the oxygen minimum zone. Cross-shelf gradients in productivity and bottom water residence times drive the strength of DO (DIC) decrease (increase) as water transits across a productive continental shelf.
Demonstrator calling for action against ocean acidification at the People's Climate March (2017).
Ocean acidification: mean seawater pH. Mean seawater pH is shown based on in-situ measurements of pH from the Aloha station.
"Present day" (1990s) sea surface pH
Present day alkalinity
"Present day" (1990s) sea surface anthropogenic {{chem|CO|2}}
Vertical inventory of "present day" (1990s) anthropogenic {{chem|CO|2}}
Change in surface {{chem|CO|3|2-}} ion from the 1700s to the 1990s
Present day DIC
Pre-Industrial DIC
A NOAA (AOML) in situ {{chem|CO|2}} concentration sensor (SAMI-CO2), attached to a Coral Reef Early Warning System station, utilized in conducting ocean acidification studies near coral reef areas
A NOAA (PMEL) moored autonomous {{chem|CO|2}} buoy used for measuring {{chem|CO|2}} concentration and ocean acidification studies

Ocean acidification has occurred previously in Earth's history, and the resulting ecological collapse in the oceans had long-lasting effects on global carbon cycling and climate.

Crystal structure of dry ice

Carbon dioxide

8 links

Chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms.

Chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms.

Crystal structure of dry ice
Stretching and bending oscillations of the CO2 carbon dioxide molecule. Upper left: symmetric stretching. Upper right: antisymmetric stretching. Lower line: degenerate pair of bending modes.
Pellets of "dry ice", a common form of solid carbon dioxide
Pressure–temperature phase diagram of carbon dioxide. Note that it is a log-lin chart.
Carbon dioxide bubbles in a soft drink
Dry ice used to preserve grapes after harvest
Use of a CO2 fire extinguisher
Comparison of the pressure–temperature phase diagrams of carbon dioxide (red) and water (blue) as a log-lin chart with phase transitions points at 1 atmosphere
A carbon-dioxide laser
Keeling curve of the atmospheric CO2 concentration
Atmospheric CO2 annual growth rose 300% since the 1960s.
Annual flows from anthropogenic sources (left) into Earth's atmosphere, land, and ocean sinks (right) since the 1960s. Units in equivalent gigatonnes carbon per year.
Pterapod shell dissolved in seawater adjusted to an ocean chemistry projected for the year 2100.
Overview of the Calvin cycle and carbon fixation
Overview of photosynthesis and respiration. Carbon dioxide (at right), together with water, form oxygen and organic compounds (at left) by photosynthesis, which can be respired  to water and (CO2).
Symptoms of carbon dioxide toxicity, by increasing volume percent in air.
Rising levels of CO2 threatened the Apollo 13 astronauts who had to adapt cartridges from the command module to supply the carbon dioxide scrubber in the Lunar Module, which they used as a lifeboat.
CO2 concentration meter using a nondispersive infrared sensor

As the source of available carbon in the carbon cycle, atmospheric carbon dioxide is the primary carbon source for life on Earth.

Schematic showing both terrestrial and geological sequestration of carbon dioxide emissions from heavy industry, such as a chemical plant.

Carbon sequestration

3 links

Schematic showing both terrestrial and geological sequestration of carbon dioxide emissions from heavy industry, such as a chemical plant.
Global proposed vs. implemented annual CO2 sequestration. More than 75% of proposed gas processing projects have been implemented, with corresponding figures for other industrial projects and power plant projects being about 60% and 10%, respectively.
An oceanic phytoplankton bloom in the South Atlantic Ocean, off the coast of Argentina. Encouraging such blooms with iron fertilization could lock up carbon on the seabed.
Biochar can be landfilled, used as a soil improver or burned using carbon capture and storage

Carbon sequestration is the process of storing carbon in a carbon pool.

A, B, and C represent the soil profile, a notation firstly coined by Vasily Dokuchaev (1846–1903), the father of pedology. Here, A is the topsoil; B is a regolith; C is a saprolite (a less-weathered regolith); the bottom-most layer represents the bedrock.

Soil

4 links

Mixture of organic matter, minerals, gases, liquids, and organisms that together support life.

Mixture of organic matter, minerals, gases, liquids, and organisms that together support life.

A, B, and C represent the soil profile, a notation firstly coined by Vasily Dokuchaev (1846–1903), the father of pedology. Here, A is the topsoil; B is a regolith; C is a saprolite (a less-weathered regolith); the bottom-most layer represents the bedrock.
Surface-water-gley developed in glacial till in Northern Ireland
Soil profile: Darkened topsoil and reddish subsoil layers are typical of humid subtropical climate regions.
Desertification
Erosion control

With respect to Earth's carbon cycle, soil acts as an important carbon reservoir, and it is potentially one of the most reactive to human disturbance and climate change.

Average surface air temperatures from 2011 to 2021 compared to the 1956–1976 average

Climate change

4 links

Contemporary climate change includes both global warming and its impacts on Earth's weather patterns.

Contemporary climate change includes both global warming and its impacts on Earth's weather patterns.

Average surface air temperatures from 2011 to 2021 compared to the 1956–1976 average
Change in average surface air temperature since the industrial revolution, plus drivers for that change. Human activity has caused increased temperatures, with natural forces adding some variability.
Global surface temperature reconstruction over the last 2000 years using proxy data from tree rings, corals, and ice cores in blue. Directly observed data is in red.
Drivers of climate change from 1850–1900 to 2010–2019. There was no significant contribution from internal variability or solar and volcanic drivers.
concentrations over the last 800,000 years as measured from ice cores (blue/green) and directly (black)
The Global Carbon Project shows how additions to since 1880 have been caused by different sources ramping up one after another.
The rate of global tree cover loss has approximately doubled since 2001, to an annual loss approaching an area the size of Italy.
Sea ice reflects 50% to 70% of incoming solar radiation while the dark ocean surface only reflects 6%, so melting sea ice is a self-reinforcing feedback.
Projected global surface temperature changes relative to 1850–1900, based on CMIP6 multi-model mean changes.
The sixth IPCC Assessment Report projects changes in average soil moisture that can disrupt agriculture and ecosystems. A reduction in soil moisture by one standard deviation means that average soil moisture will approximately match the ninth driest year between 1850 and 1900 at that location.
Historical sea level reconstruction and projections up to 2100 published in 2017 by the U.S. Global Change Research Program
The IPCC Sixth Assessment Report (2021) projects that extreme weather will be progressively more common as the Earth warms.
Scenarios of global greenhouse gas emissions. If all countries achieve their current Paris Agreement pledges, average warming by 2100 would still significantly exceed the maximum 2 °C target set by the Agreement.
Coal, oil, and natural gas remain the primary global energy sources even as renewables have begun rapidly increasing.
Economic sectors with more greenhouse gas contributions have a greater stake in climate change policies.
Most emissions have been absorbed by carbon sinks, including plant growth, soil uptake, and ocean uptake (2020 Global Carbon Budget).
Since 2000, rising emissions in China and the rest of world have surpassed the output of the United States and Europe.
Per person, the United States generates at a far faster rate than other primary regions.
Academic studies of scientific consensus reflect that the level of consensus correlates with expertise in climate science.
Data has been cherry picked from short periods to falsely assert that global temperatures are not rising. Blue trendlines show short periods that mask longer-term warming trends (red trendlines). Blue dots show the so-called global warming hiatus.
The 2017 People's Climate March took place in hundreds of locations. Shown: the Washington, D.C. march, protesting policies of then-U.S. President Trump.
Tyndall's ratio spectrophotometer (drawing from 1861) measured how much infrared radiation was absorbed and emitted by various gases filling its central tube.
alt=Underwater photograph of branching coral that is bleached white|Ecological collapse. Bleaching has damaged the Great Barrier Reef and threatens reefs worldwide.<ref>{{Cite web|url=https://sos.noaa.gov/datasets/coral-reef-risk-outlook/|title=Coral Reef Risk Outlook|access-date=4 April 2020|publisher=National Oceanic and Atmospheric Administration|quote=At present, local human activities, coupled with past thermal stress, threaten an estimated 75 percent of the world's reefs. By 2030, estimates predict more than 90% of the world's reefs will be threatened by local human activities, warming, and acidification, with nearly 60% facing high, very high, or critical threat levels.}}</ref>
alt=Photograph of evening in a valley settlement. The skyline in the hills beyond is lit up red from the fires.|Extreme weather. Drought and high temperatures worsened the 2020 bushfires in Australia.<ref>{{harvnb|Carbon Brief, 7 January|2020}}.</ref>
alt=The green landscape is interrupted by a huge muddy scar where the ground has subsided.|Arctic warming. Permafrost thaws undermine infrastructure and release methane, a greenhouse gas.
alt=An emaciated polar bear stands atop the remains of a melting ice floe.|Habitat destruction. Many arctic animals rely on sea ice, which has been disappearing in a warming Arctic.<ref>{{harvnb|IPCC AR5 WG2 Ch28|2014|p=1596|ps=: "Within 50 to 70 years, loss of hunting habitats may lead to elimination of polar bears from seasonally ice-covered areas, where two-thirds of their world population currently live."}}</ref>
alt=Photograph of a large area of forest. The green trees are interspersed with large patches of damaged or dead trees turning purple-brown and light red.|Pest propagation. Mild winters allow more pine beetles to survive to kill large swaths of forest.<ref>{{Cite web|url=https://www.nps.gov/romo/learn/nature/climatechange.htm|title=What a changing climate means for Rocky Mountain National Park|publisher=National Park Service|access-date=9 April 2020}}</ref>
Environmental migration. Sparser rainfall leads to desertification that harms agriculture and can displace populations. Shown: Telly, Mali (2008).<ref>{{harvnb|Serdeczny|Adams|Baarsch|Coumou|2016}}.</ref>
Agricultural changes. Droughts, rising temperatures, and extreme weather negatively impact agriculture. Shown: Texas, US (2013).<ref>{{harvnb|IPCC SRCCL Ch5|2019|pp=439, 464}}.</ref>
Tidal flooding. Sea-level rise increases flooding in low-lying coastal regions. Shown: Venice, Italy (2004).<ref name="NOAAnuisance">{{cite web|url=http://oceanservice.noaa.gov/facts/nuisance-flooding.html |title=What is nuisance flooding? |author=National Oceanic and Atmospheric Administration |access-date=April 8, 2020}}</ref>
Storm intensification. Bangladesh after Cyclone Sidr (2007) is an example of catastrophic flooding from increased rainfall.<ref>{{harvnb|Kabir|Khan|Ball|Caldwell|2016}}.</ref>
Heat wave intensification. Events like the June 2019 European heat wave are becoming more common.<ref>{{harvnb|Van Oldenborgh|Philip|Kew|Vautard|2019}}.</ref>

Afterwards, the ocean's overturning circulation distributes it deep into the ocean's interior, where it accumulates over time as part of the carbon cycle.

Biogeochemical cycle

3 links

Pathway by which a chemical substance cycles ( is turned over or moves through) the biotic and the abiotic compartments of Earth.

Pathway by which a chemical substance cycles ( is turned over or moves through) the biotic and the abiotic compartments of Earth.

The fast cycle operates through the biosphere, including exchanges between land, atmosphere, and oceans. The yellow numbers are natural fluxes of carbon in billions of tons (gigatons) per year. Red are human contributions and white are stored carbon.
{{center|Examples of major biogeochemical processes}}
alt=Diagram of the nutrient cycle|Nutrient cycle
The implications of shifts in the global carbon cycle due to human activity are concerning scientists.<ref>Avelar, S., van der Voort, T.S. and Eglinton, T.I. (2017) "Relevance of carbon stocks of marine sediments for national greenhouse gas inventories of maritime nations". Carbon balance and management, 12(1): 10.{{doi|10.1186/s13021-017-0077-x}}. CC-BY icon.svg Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License {{Webarchive|url=https://web.archive.org/web/20171016050101/https://creativecommons.org/licenses/by/4.0/ |date=2017-10-16 }}.</ref>
alt=Diagram of the carbon cycle|Carbon cycle
alt=Diagram of the nitrogen cycle|Nitrogen cycle
alt=Diagram of the phosphorus cycle|Phosphorus cycle
alt=Diagram of the sulfur cycle|Sulfur cycle
alt=Diagram of the rock cycle|Rock cycle
alt=Diagram of the water cycle|Water cycle
Chloroplasts conduct photosynthesis in plant cells and other eukaryotic organisms.
Kerogen cycle{{hsp}}<ref>{{cite journal |doi = 10.1038/nature14400|title = Global carbon export from the terrestrial biosphere controlled by erosion|year = 2015|last1 = Galy|first1 = Valier|last2 = Peucker-Ehrenbrink|first2 = Bernhard|last3 = Eglinton|first3 = Timothy|journal = Nature|volume = 521|issue = 7551|pages = 204–207|pmid = 25971513|bibcode = 2015Natur.521..204G|s2cid = 205243485}}</ref><ref>{{cite journal |doi = 10.1016/S0146-6380(97)00056-9|title = Comparative organic geochemistries of soils and marine sediments|year = 1997|last1 = Hedges|first1 = J.I|last2 = Oades|first2 = J.M|journal = Organic Geochemistry|volume = 27|issue = 7–8|pages = 319–361}}</ref>
Coal is a reservoir of carbon

There are biogeochemical cycles for chemical elements, such as for calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, iron and sulfur, as well as molecular cycles, such as for water and silica.

Since oil fields are located only at certain places on earth, only some countries are oil-independent; the other countries depend on the oil-production capacities of these countries

Fossil fuel

4 links

Hydrocarbon-containing material formed naturally in the earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel.

Hydrocarbon-containing material formed naturally in the earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel.

Since oil fields are located only at certain places on earth, only some countries are oil-independent; the other countries depend on the oil-production capacities of these countries
A petrochemical refinery in Grangemouth, Scotland, UK
An oil well in the Gulf of Mexico
The Global Carbon Project shows how additions to since 1880 have been caused by different sources ramping up one after another.
Global surface temperature reconstruction over the last 2000 years using proxy data from tree rings, corals, and ice cores in blue. Directly observational data is in red, with all data showing a 5 year moving average.
In 2020, renewables overtook fossil fuels as the European Union's main source of electricity for the first time.

Natural processes on Earth, mostly absorption by the ocean, can only remove a small part of this.

Net DOC production (NDP) in the upper 74 metres (a) and net DOC export (NDX) below 74 metres (b). At steady state, the global summation of NDX is equal to that of NDP, and is 2.31 ± 0.60 PgC yr.

Dissolved organic carbon

3 links

Fraction of organic carbon operationally defined as that which can pass through a filter with a pore size typically between 0.22 and 0.7 micrometers.

Fraction of organic carbon operationally defined as that which can pass through a filter with a pore size typically between 0.22 and 0.7 micrometers.

Net DOC production (NDP) in the upper 74 metres (a) and net DOC export (NDX) below 74 metres (b). At steady state, the global summation of NDX is equal to that of NDP, and is 2.31 ± 0.60 PgC yr.
Filtered (0.2 μm) coastal marine waters collected at various locations around the United Kingdom. The differences in colour is due to the range of soil-derived carbon input to the coastal water, with dark brown (left) indicating a high soil-derived carbon contribution and near-clear water (right) indicating a low soil-derived carbon contribution.
Regions of significant net DOC production (broad arrows) include coastal and equatorial upwelling regions that support much of the global new production. DOC is transported into and around the subtropical gyres with the wind-driven surface circulation. Export takes place if exportable DOC (elevated concentrations indicated by dark blue fields) is present during overturning of the water column. precursor for deep and intermediate water mass formation. DOC is also exported with subduction in the gyres. In regions where DOCenriched subtropical water is prevented by polar frontal systems from serving as a precursor for overturning circulation (such as at the sites of Antarctic Bottom Water formation in the Southern Ocean) DOC export is a weak component of the biological pump. Waters south of the Antarctic Polar Front lack significant exportable DOC (depicted by light blue field) during winter.
Left side: classic description of the carbon flow from photosynthetic algae to grazers and higher trophic levels in the food chain.
Right side: microbial loop, with bacteria using dissolved organic carbon to gain biomass, which then re-enters the classic carbon flow through protists.
In panel (A) oceanic DOC stocks are shown in black circles with red font and units are Pg-C. DOC fluxes are shown in black and white font and units are either Tg-C yr–1 or Pg-C yr–1. Letters in arrows and associated flux values correspond to descriptions displayed in (B), which lists sources and sinks of oceanic DOC.
South-East Asia is home to one of the world's largest stores of tropical peatland and accounts for roughly 10 % of the global land-to-sea dissolved organic carbon (DOC) flux. The rivers carry high coloured dissolved organic matter (CDOM) concentrations, shown here interfacing with ocean shelf water.
upright=2.4|{{center|Removal of refractory DOC in the ocean}} {{align|left|Phytoplankton production and food web dynamics in surface waters release a diverse mixture of dissolved molecules with varying reactivities. Bacteria and archaea utilize labile and semi-labile forms of DOC in surface and mesopelagic waters of the upper ocean, leaving behind a vast reservoir of refractory DOC (RDOC) that persists in the ocean for millennia. The ocean is a patchy environment that harbors a great diversity of microbes and physicochemical processes with the potential to remove refractory DOC when these molecules encounter environmental conditions and microbes that can degrade them. Physical mixing transports refractory DOC throughout the ocean realm and thereby increases the likelihood of its removal. Deep ocean waters can be entrained into hydrothermal circulation and associated DOC can be removed by thermal degradation. Sinking particles from the upper ocean release labile DOC (LDOC) that triggers hot spots of microbial activity and primes the removal of refractory molecules. Mixing of subsurface waters into sunlit waters exposes refractory DOC to warmer temperatures and photochemical processes that can mineralize and transform refractory molecules into simple compounds (e.g., pyruvate, formaldehyde) for rapid microbial utilization. Thus, it appears the lifetime of refractory molecules in the ocean is regulated by the rate of global overturning circulation (GOC). This relationship indicates a slowing of GOC could lead to an increase in the reservoir size of refractory DOC, assuming a constant production rate of refractory DOC (inset panel).<ref name="Shen and Benner 2018">{{cite journal |last1=Shen |first1=Yuan |last2=Benner |first2=Ronald |title=Mixing it up in the ocean carbon cycle and the removal of refractory dissolved organic carbon |journal=Scientific Reports |date=2018 |volume=8 |issue=1 |page=2542 |doi=10.1038/s41598-018-20857-5|pmid=29416076 |pmc=5803198 }} CC-BY icon.svg Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.</ref>}}
{{center|Environmental processes controlling the apparent recalcitrance of oceanic DOC}} The dots represent DOC molecules and arrows represent physicochemical and biological processes that impact DOC concentration and molecular composition. In the surface ocean, DOC derived from primary production is rapidly remineralized or transformed through microbial degradation (black arrow), photochemical degradation (yellow arrow), or particle exchange (green arrow). Labile components are removed down the water column and DOC becomes diluted by processes, such as particle exchange (brown arrow), sediment dissolution (gray arrow), and microbial reworking (white arrow), which continue to alter, add, and/or remove molecules from the bulk DOC pool. Thus, the apparent recalcitrance of DOC in the ocean’s interior is an emergent property that is largely controlled by environmental context.

DOC fuels marine food webs, and is a major component of the Earth's carbon cycling.

Crystal structure of calcite

Calcium carbonate

3 links

Chemical compound with the formula CaCO3.

Chemical compound with the formula CaCO3.

Crystal structure of calcite
Calcite is the most stable polymorph of calcium carbonate. It is transparent to opaque. A transparent variety called Iceland spar (shown here) was used to create polarized light in the 19th century.
Calcium carbonate chunks from clamshell
Surface precipitation of CaCO3 as tufa in Rubaksa, Ethiopia
Tufa at Huanglong, Sichuan
500-milligram calcium supplements made from calcium carbonate
Travertine calcium carbonate deposits from a hot spring
Electron micrograph of needle-like calcium carbonate crystals formed as limescale in a kettle
Around 2 g of calcium-48 carbonate

Carbonate is found frequently in geologic settings and constitutes an enormous carbon reservoir.

Theoretically predicted phase diagram of carbon, from 1989. Newer work indicates that the melting point of diamond (top-right curve) does not go above about 9000 K.

Carbon

2 links

Chemical element with the symbol C and atomic number 6.

Chemical element with the symbol C and atomic number 6.

Theoretically predicted phase diagram of carbon, from 1989. Newer work indicates that the melting point of diamond (top-right curve) does not go above about 9000 K.
A large sample of glassy carbon
Some allotropes of carbon: a) diamond; b) graphite; c) lonsdaleite; d–f) fullerenes (C60, C540, C70); g) amorphous carbon; h) carbon nanotube
Comet C/2014 Q2 (Lovejoy) surrounded by glowing carbon vapor
Graphite ore, shown with a penny for scale
Raw diamond crystal
"Present day" (1990s) sea surface dissolved inorganic carbon concentration (from the GLODAP climatology)
Diagram of the carbon cycle. The black numbers indicate how much carbon is stored in various reservoirs, in billions tonnes ("GtC" stands for gigatonnes of carbon; 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.
Structural formula of methane, the simplest possible organic compound.
Correlation between the carbon cycle and formation of organic compounds. In plants, carbon dioxide formed by carbon fixation can join with water in photosynthesis ( green ) to form organic compounds, which can be used and further converted by both plants and animals.
This anthracene derivative contains a carbon atom with 5 formal electron pairs around it.
Antoine Lavoisier in his youth
Carl Wilhelm Scheele
Diamond output in 2005
Pencil leads for mechanical pencils are made of graphite (often mixed with a clay or synthetic binder).
Sticks of vine and compressed charcoal
A cloth of woven carbon fibres
Silicon carbide single crystal
The C60 fullerene in crystalline form
Tungsten carbide endmills
Worker at carbon black plant in Sunray, Texas (photo by John Vachon, 1942)

The paths of carbon in the environment form the carbon cycle.