Annual mean sea surface dissolved inorganic carbon (DIC) for the present day (1990s) from the Global Ocean Data Analysis Project climatology. Note the missing data in certain oceanic provinces including the Arctic Ocean, the Caribbean Sea, the Mediterranean Sea and the Malay Archipelago.
The vast majority of carbon on Earth is located underground in inorganic forms such as the carbonates in sedimentary rock, mostly calcite (CaCO3), and in organic forms such as...
Tracking the Global Carbon CycleLast Updated on 2013-07-11 09:56:26
Carbon dioxide (CO2) is the primary anthropogenic (man-made) greenhouse gas in terms of concentration and effect. It is responsible for about one-third of the global warming that derives from human activities.  Concentrations of CO2 in the atmosphere depend on the global carbon cycle that accounts for the fluxes of carbon among various storage pools. The vast majority of carbon on Earth is part of limestone and other sedimentary rocks. The decomposition of rocks, called weathering, as well as the high temperatures used during cement production, release CO2 from limestone and enters the atmosphere or dissolves in bodies of water.
Photosynthetic organisms absorb CO2 from the atmosphere or bodies of water and then use solar radiation to convert this low-energy carbon into the high-energy carbon in organic compounds. This process reverses when organisms breathe in and out (respire) or... More »
Soil Microorganisms and BiogeochemistryLast Updated on 2010-12-17 00:00:00
The vast majority of carbon on Earth is located underground in inorganic forms such as the carbonates in sedimentary rock, mostly calcite (CaCO3), and in organic forms such as deposits of coal, oil, and natural gas and accumulations of soil organic matter. Each year, soil microorganisms, in a process known as decomposition, break down about 2.5% of soil organic matter, converting the organic carbon to carbon dioxide (CO2) which is released to the atmosphere. Roughly an equivalent amount of organic carbon returns to soils as animal and especially plant material, a process known as soil organic carbon sequestration.
The balance between carbon decomposition and sequestration has a direct effect on atmospheric CO2levels. Evidence for this includes the prominent seasonal cycles of atmospheric CO2 concentrations. Atmospheric CO2 concentrations decrease during the summer, when... More »
Microbial Electrosynthesis: Carbon Dioxide and Water to Extracellular OrganicsLast Updated on 2010-12-11 00:00:00
This article appeared first in mBio, an open-access journal of the American Society for Microbiology operating under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.
The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth.
Microbial Electrosynthesis: Feeding Microbes Electricity
To Convert Carbon Dioxide and Water to Multicarbon
Extracellular Organic Compounds
The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on... More »
PermafrostLast Updated on 2010-05-20 00:00:00
A soil is considered permafrost if its temperature remains permanently below the melting point of water for at least two years. Such permafrost soil is ubiquitous in high latitude (e.g. in Siberia, Alaska and the Antarctic) but can also be found in mountainous areas at lower latitudes. Typically, the below-ground temperature will be less variable from season to season than the air temperature, with temperatures tending to increase with depth.
Permafrost typically occurs during glacial periods. The thickness of a permafrost layer can reach from a few decimetres to well over one kilometre, while it may extend in area from small patches of a few tens of square metres to thousands of square kilometres. Since our present glacial period is considered an interglacial within the fifth Ice age there are presently large areas of the Earth that are classified as permafrost. Permafrost... More »
Nuclear powerLast Updated on 2010-05-10 00:00:00
Nuclear power is the generation of electricity from controlled reactions within the nucleii of atoms that release energy used to boil water, the steam from which drives a turbine to generate electricity . All commercial nuclear plants presently rely upon nuclear fission reactions.
As of 2010, approximately 14 percent of the world's electricity was derived from nuclear power, chiefly centered in the United States (with 31% of the world's total nuclear power capacity), France (16%), and Japan (10%).
The International Atomic Energy Agency (IAEA) reports that, as of November 21, 2012, there are 437 nuclear power reactors in operation in 30 countries, plus Taiwan. Another 64 reactors under construction in 14 countries which if operational today would increase the worldwide electrical generation capacity of nuclear power by 17%. One hundred and forty reactors have been... More »
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