Carbon dioxide in Earth's atmosphere

carbon dioxide emissionsatmospheric carbon dioxideCO2 emissions
The increased radiative forcing due to increased CO 2 in the Earth's atmosphere is based on the physical properties of CO 2 and the non-saturated absorption windows where CO 2 absorbs outgoing long-wave energy. Atmospheric carbon dioxide plays an integral role in the Earth's carbon cycle whereby carbon dioxide is removed from the atmosphere by some natural processes such as photosynthesis and deposition of carbonates, to form limestones for example, and added back to the atmosphere by other natural processes such as respiration and the acid dissolution of carbonate deposits. There are two broad carbon cycles on Earth: the fast carbon cycle and the slow carbon cycle.

Dry ice

dry-icecarbon dioxide icecarbon dioxide
Dry ice is the solid form of carbon dioxide (CO 2 ), a molecule consisting of a single carbon atom bonded to two oxygen atoms. Dry ice is colorless, non-flammable, with a sour zesty odor, and can lower the pH of a solution when dissolved in water, forming carbonic acid (H 2 CO 3 ). At pressures below 5.13 atm and temperatures below -56.4 C (the triple point), CO 2 changes from a solid to a gas with no intervening liquid form, through a process called sublimation. The opposite process is called deposition, where CO 2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at -78.5 C or 194.65 K.


turfpeat cuttingpeat extraction
This leads to lower levels of CO 2 storage than the original peat bog. At 106 g CO 2 /MJ, the carbon dioxide emissions of peat are higher than those of coal (at 94.6 g CO 2 /MJ) and natural gas (at 56.1). According to one study, increasing the average amount of wood in the fuel mixture from the current 2.6% to 12.5% would take the emissions down to 93 g CO 2 /MJ. That said, little effort is being made to achieve this. The International Mire Conservation Group (IMCG) in 2006 urged the local and national governments of Finland to protect and conserve the remaining pristine peatland ecosystems.


Cellular respiration, for instance, is the oxidation of glucose (C 6 H 12 O 6 ) to CO 2 and the reduction of oxygen to water. The summary equation for cell respiration is: : C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O The process of cell respiration also depends heavily on the reduction of NAD + to NADH and the reverse reaction (the oxidation of NADH to NAD + ). Photosynthesis and cellular respiration are complementary, but photosynthesis is not the reverse of the redox reaction in cell respiration: Biological energy is frequently stored and released by means of redox reactions. Photosynthesis involves the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen.


coal seamcoal industrycoal-fired
The largest and most long term effect of coal use is the release of carbon dioxide, a greenhouse gas that causes climate change and global warming. Coal-fired power plants were the single largest contributor to the growth in global CO 2 emissions in 2018, 40% of the total fossil fuel emissions. Coal mining can emit methane, another greenhouse gas. In 2016 world gross carbon dioxide emissions from coal usage were 14.5 giga tonnes. For every megawatt-hour generated, coal-fired electric power generation emits around a tonne of carbon dioxide, which is double the approximately 500 kg of carbon dioxide released by a natural gas-fired electric plant.

Greenhouse gas

greenhouse gasescarbon emissionsgreenhouse gas emissions
The primary greenhouse gases in Earth's atmosphere are water vapor (H 2 O), carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), and ozone (O 3 ). Without greenhouse gases, the average temperature of Earth's surface would be about -18 °C, rather than the present average of 15 °C. The atmospheres of Venus, Mars and Titan also contain greenhouse gases. Human activities since the beginning of the Industrial Revolution (around 1750) have produced a 45% increase in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 415 ppm in 2019.

Ocean acidification

acidificationacidified the oceansacidification of the oceans
Also, elevated CO 2 in marine environments can lead to neurotransmitter interference in both predator and prey fish which increases their mortality rate. It has also been shown that when fish spend considerable time in high concentrations of dissolved CO 2 up to 50,000 micro-atmospheres (μatm) of CO 2 in marine environments, cardiac failure leading to death is much more common than in normal CO 2 environments. In addition, fish that live in high CO 2 environments are required to spend more of their energy to keep their acid/base regulation in check.

Dry-ice blasting

dry ice blastingblast cleaningCO 2 dry ice process
*Carbon dioxide cleaning Blasting with Solid CO 2 Flyer, from the Fraunhofer Institute. Messer Group 2007 article on Dry Ice Blasting (pdf, pp 8–12).


deforestedland clearingforest clearing
According to the Intergovernmental Panel on Climate Change deforestation, mainly in tropical areas, could account for up to one-third of total anthropogenic carbon dioxide emissions. But recent calculations suggest that carbon dioxide emissions from deforestation and forest degradation (excluding peatland emissions) contribute about 12% of total anthropogenic carbon dioxide emissions with a range from 6% to 17%. Deforestation causes carbon dioxide to linger in the atmosphere. As carbon dioxide accrues, it produces a layer in the atmosphere that traps radiation from the sun. The radiation converts to heat which causes global warming, which is better known as the greenhouse effect.

Elizabeth Haldane

Elizabeth Sanderson HaldaneE. S. HaldaneE.S. Haldane
Elizabeth Sanderson Haldane (27 May 1862 – 24 December 1937) was an author, biographer, philosopher, suffragist, nursing administrator, and social welfare worker. She was the sister of Richard Burdon Haldane, 1st Viscount Haldane and John Scott Haldane, and became the first female Justice of the Peace in Scotland in 1920. She was made a Companion of Honour in 1918. Elizabeth Haldane was born on 27 May 1862 at 17 Charlotte Square, Edinburgh. Her father was Robert Haldane of Cloan House near Auchterarder, Perthshire and her mother was Mary Elizabeth Sanderson. She was educated by a succession of tutors and visiting schoolmasters.

Carbonic acid

carbonicvolatile acidBicarbonate
When carbon dioxide dissolves in water, it exists in chemical equilibrium with carbonic acid: : The hydration equilibrium constant at 25 °C is called K h, which in the case of carbonic acid is [H 2 CO 3 ]/[CO 2 ] ≈ 1.7×10 −3 in pure water and ≈ 1.2×10 −3 in seawater. Hence, the majority of the carbon dioxide is not converted into carbonic acid, remaining as CO 2 molecules. In the absence of a catalyst, the equilibrium is reached quite slowly. The rate constants are 0.039 s −1 for the forward reaction (CO 2 + H 2 O → H 2 CO 3 ) and 23 s −1 for the reverse reaction (H 2 CO 3 → CO 2 + H 2 O).

Joseph Black

BlackBlack, JosephDr Black’s
Joseph Black (16 April 1728 – 6 December 1799) was a Scottish physicist and chemist, known for his discoveries of magnesium, latent heat, specific heat, and carbon dioxide. He was Professor of Anatomy and Chemistry at the University of Glasgow for 10 years from 1756, and then Professor of Medicine and Chemistry at the University of Edinburgh from 1766, teaching and lecturing there for more than 30 years. The chemistry buildings at both the University of Edinburgh and the University of Glasgow are named after Black. Black was born in Bordeaux, France, the sixth of the 12 children of Margaret Gordon (d. 1747) and John Black.

Carbon cycle

carboncarbon cyclingglobal carbon cycle
Carbon in the Earth's atmosphere exists in two main forms: carbon dioxide and methane. Both of these gases absorb and retain heat in the atmosphere and are partially responsible for the greenhouse effect. Methane produces a larger greenhouse effect per volume as compared to carbon dioxide, but it exists in much lower concentrations and is more short-lived than carbon dioxide, making carbon dioxide the more important greenhouse gas of the two. Carbon dioxide is removed from the atmosphere primarily through photosynthesis and enters the terrestrial and oceanic biospheres.

Richard Haldane, 1st Viscount Haldane

Richard HaldaneLord HaldaneViscount Haldane
Apart from his legal and political careers, Haldane was also an influential writer on philosophy, in recognition of which he was elected a Fellow of the British Academy in 1914. Haldane was born at 17 Charlotte Square, Edinburgh, the son of Robert Haldane and his wife Mary Elizabeth, daughter of Richard Burdon-Sanderson. He was the grandson of the Scottish evangelist James Alexander Haldane, the brother of respiratory physiologist John Scott Haldane, Sir William Haldane and author Elizabeth Haldane, and the uncle of J. B. S. Haldane and Naomi Mitchison. He received his first education at the Edinburgh Academy, and then at the University of Göttingen.


Through the process of photosynthesis, most plants use the energy in sunlight to convert carbon dioxide from the atmosphere, plus water, into simple sugars. These sugars are then used as building blocks and form the main structural component of the plant. Chlorophyll, a green-colored, magnesium-containing pigment is essential to this process; it is generally present in plant leaves, and often in other plant parts as well. Parasitic plants, on the other hand, use the resources of their host to provide the materials needed for metabolism and growth.

Calcium carbonate

CaCO 3 calcareouscalcium
reacts with acids, releasing carbon dioxide (technically speaking, carbonic acid, but that disintegrates quickly to CO 2 and H 2 O):. CaCO 3 (s) + 2 H + (aq) → Ca 2+ (aq) + CO 2 (g) + H 2 O(l). releases carbon dioxide upon heating, called a thermal decomposition reaction, or calcination (to above 840 °C in the case of CaCO 3 ), to form calcium oxide, commonly called quicklime, with reaction enthalpy 178 kJ/mol:. CaCO 3 (s) → CaO(s) + CO 2 (g). CaO + H 2 O → Ca(OH) 2.


brewing industrybrewingbeers
A metal keg is pressurised with carbon dioxide (CO 2 ) gas which drives the beer to the dispensing tap or faucet. Some beers may be served with a nitrogen/carbon dioxide mixture. Nitrogen produces fine bubbles, resulting in a dense head and a creamy mouthfeel. Some types of beer can also be found in smaller, disposable kegs called beer balls. In traditional pubs, the pull levers for major beer brands may include the beer's logo and trademark. In the 1980s, Guinness introduced the beer widget, a nitrogen-pressurised ball inside a can which creates a dense, tight head, similar to beer served from a nitrogen system.

Covalent bond

covalentcovalentlycovalently bonded
Such covalent substances are usually gases, for example, HCl, SO 2, CO 2, and CH 4. In molecular structures, there are weak forces of attraction. Such covalent substances are low-boiling-temperature liquids (such as ethanol), and low-melting-temperature solids (such as iodine and solid CO 2 ). Macromolecular structures have large numbers of atoms linked by covalent bonds in chains, including synthetic polymers such as polyethylene and nylon, and biopolymers such as proteins and starch. Network covalent structures (or giant covalent structures) contain large numbers of atoms linked in sheets (such as graphite), or 3-dimensional structures (such as diamond and quartz).

Fossil fuel

fossil fuelsoil and gasOil & Gas
The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes) of carbon dioxide (CO 2 ) per year. It is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year. Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming. A global movement towards the generation of low-carbon renewable energy is underway to help reduce global greenhouse-gas emissions.

Bituminous coal

black coalbituminouscoal
Within the coal mining industry, this type of coal is known for releasing the largest amounts of firedamp, a dangerous mixture of gases that can cause underground explosions. Extraction of bituminous coal demands the highest safety procedures involving attentive gas monitoring, good ventilation and vigilant site management. Bituminous coals are graded according to vitrinite reflectance, moisture content, volatile content, plasticity and ash content. Generally, the highest value bituminous coals have a specific grade of plasticity, volatility and low ash content, especially with low carbonate, phosphorus, and sulfur.


The chemical aspects of plant decomposition always involve the release of carbon dioxide. In fact, decomposition contributes over 90 percent of carbon dioxide released each year. The decomposition of food, either plant or animal, called spoilage in this context, is an important field of study within food science. Food decomposition can be slowed down by conservation. The spoilage of meat occurs, if the meat is untreated, in a matter of hours or days and results in the meat becoming unappetizing, poisonous or infectious.

Carbonic anhydrase

Carbonic anhydrasescarboanydrasecarbonate dehydratase
The tissues are more acidic than the lungs because of the fact that carbon dioxide is produced by respiration and it reacts with water in the tissues to produce the hydrogen protons. Due to the fact that the carbon dioxide concentration is higher, equilibrium shifts to the right, to the bicarbonate side. The opposite is seen in the lungs where carbon dioxide is being released so its concentration is lower so equilibrium shifts to the left towards carbon dioxide to try and raise its concentration. The reaction that shows the catalyzation of carbonic anhydrase in our tissues is: CO 2 + H 2 O H 2 CO 3 H + + HCO 3 -.

Metal carbon dioxide complex

Metal carbon dioxide complexes are coordination complexes that contain carbon dioxide ligands. Aside from the fundamental interest in the coordination chemistry of simple molecules, studies in this field are motivated by the possibility that transition metals might catalyze useful transformations of CO 2. This research is relevant both to organic synthesis and to the production of "solar fuels" that would avoid the use of petroleum-based fuels. Carbon dioxide binds to metals in only a few ways. The bonding mode depends on the electrophilicity and basicity of the metal centre.

Naomi Mitchison

Naomi (née Haldane)Mitchison, N.Naomi Haldane
Naomi Mary Margaret Haldane was born in Edinburgh, the daughter and younger child of the physiologist John Scott Haldane and his wife (Louisa) Kathleen Trotter. Naomi's parents came from different political backgrounds, her father being a Liberal and her mother from a Conservative and pro-imperialist family. However, both families were of landed stock; the Haldane family had been feudal barons of Gleneagles since the 13th century, but were nevertheless known for their achievements in other spheres. Today the best-known member of the family is probably Naomi's elder brother, the biologist J. B. S.


carbonatescarbonaceousCO 3
In aqueous solution, carbonate, bicarbonate, carbon dioxide, and carbonic acid exist together in a dynamic equilibrium. In strongly basic conditions, the carbonate ion predominates, while in weakly basic conditions, the bicarbonate ion is prevalent. In more acid conditions, aqueous carbon dioxide, CO 2 (aq), is the main form, which, with water, H 2 O, is in equilibrium with carbonic acid – the equilibrium lies strongly towards carbon dioxide. Thus sodium carbonate is basic, sodium bicarbonate is weakly basic, while carbon dioxide itself is a weak acid. Carbonated water is formed by dissolving CO 2 in water under pressure.