Related topics: climate change , nasa , greenhouse gas
Carbon dioxide
hideCarbon dioxide (chemical formula: CO2) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state.
Carbon dioxide is used by plants during photosynthesis to make sugars, which may either be consumed in respiration or used as the raw material to produce other organic compounds needed for plant growth and development. It is produced during respiration by plants, and by all animals, fungi and microorganisms that depend either directly or indirectly on plants for food. It is thus a major component of the carbon cycle. Carbon dioxide is generated as a by-product of the combustion of fossil fuels or the burning of vegetable matter, among other chemical processes. Large amounts of carbon dioxide are emitted from volcanoes and other geothermal processes such as hot springs and geysers and by the dissolution of carbonates in crustal rocks.
As of March 2009[update], carbon dioxide in the Earth's atmosphere is at a concentration of 387 ppm by volume. Atmospheric concentrations of carbon dioxide fluctuate slightly with the change of the seasons, driven primarily by seasonal plant growth in the Northern Hemisphere. Concentrations of carbon dioxide fall during the northern spring and summer as plants consume the gas, and rise during the northern autumn and winter as plants go dormant, die and decay. Carbon dioxide is a greenhouse gas as it transmits visible light but absorbs strongly in the infrared and near-infrared.
Carbon dioxide has no liquid state at pressures below 5.1 atmospheres. At 1 atmosphere (near mean sea level pressure), the gas deposits directly to a solid at temperatures below −78 °C and the solid sublimes directly to a gas above −78 °C. In its solid state, carbon dioxide is commonly called dry ice.
CO2 is an acidic oxide: an aqueous solution turns litmus from blue to pink. It is the anhydride of carbonic acid, an acid which is unstable and is known to exist only in aqueous solution.
CO2 is toxic in higher concentrations: 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour.
For more information about Carbon dioxide, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with carbon dioxide
The politics of climate fixes
Nov 06, 2009 |
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In the middle of a day filled with a stream of information-packed PowerPoint displays and alarming projections of what the future holds for our planet and our civilization, Judith Layzer’s talk was something ...
Reducing Agriculture's Climate Change Footprint
Nov 04, 2009 |
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(PhysOrg.com) -- Curbing greenhouse gas emissions from cultivated fields may require going beyond cutting back on nitrogen fertilizer and changing crop rotation cycles, according to research by Agricultural ...
New evidence supports 19th century idea on formation of oil and gas
Chemistry / Analytical Chemistry
Nov 04, 2009 |
4 / 5 (2) |
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Scientists in Washington, D.C. are reporting laboratory evidence supporting the possibility that some of Earth's oil and natural gas may have formed in a way much different than the traditional process described ...
UN signals delay in new climate change treaty
Oct 27, 2009 |
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(AP) -- Just weeks before an international conference on climate change, the United Nations signaled it was scaling back expectations of reaching agreement on a new treaty to slow global warning.
Where Did the Uranium Go?
Oct 26, 2009 |
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(PhysOrg.com) -- Uranium's migration through the soil depends on groundwater's chemical composition, according to a recent study by Pacific Northwest National Laboratory. Scientists showed that uraniumattached ...
Researchers identify dominant chemical that attracts mosquitoes to humans
Oct 26, 2009 |
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Scientists at the University of California, Davis, have identified the dominant odor naturally produced in humans and birds that attracts the blood-feeding Culex mosquitoes, which transmit West Nile virus ...
Ocean acidification may contribute to global shellfish decline
Space & Earth / Earth Sciences
Oct 26, 2009 |
2.7 / 5 (7) |
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Relatively minor increases in ocean acidity brought about by high levels of carbon dioxide have significant detrimental effects on the growth, development, and survival of hard clams, bay scallops, and Eastern ...
Denmark urges agreement on climate change funds
Oct 23, 2009 |
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(AP) -- Denmark urged the European Union, the United States and other rich countries to commit to financing for a new climate change deal, saying Friday that billions of dollars are needed.
Biofuel for commercial flights by 2010: IATA
Oct 23, 2009 |
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The International Air Transport Association (IATA) said Friday it would approve biofuels for commercial flights by 2010 in a bid to drastically reduce the industry's carbon footprint.
Treaty to limit CO2 should be followed by similar limits on other greenhouse pollutants
Oct 22, 2009 |
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When world leaders meet in Copenhagen in December to hash out a treaty limiting carbon dioxide emissions, they should begin planning a future summit to address other pollutants - from soot to ozone - that don't remain in ...
Climate scientists uncover major accounting flaw in Kyoto Protocol, other climate legislation
Oct 22, 2009 |
2 / 5 (3) |
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(PhysOrg.com) -- A team of 13 prominent scientists and land-use experts has identified an important but fixable error in legal accounting rules for bioenergy that could, if uncorrected, undermine efforts to reduce greenhouse ...
Ultracapacitors Make City Buses Cheaper, Greener
Oct 21, 2009 |
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(PhysOrg.com) -- A fleet of 17 buses near Shanghai has been running on ultracapacitors for the past three years, and today that technology is coming to the Washington, DC, for a one-day demonstration. Chinese ...
Professor calculates a cooler planet
Oct 20, 2009 |
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(PhysOrg.com) -- Some people fight global warming by driving fuel-efficient cars. Others weatherproof their houses or plant trees. Princeton's René Carmona does math. As the United States and other countries around ...
Astronomers do it Again: Find Organic Molecules Around Gas Planet (w/ Video)
Oct 20, 2009 |
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(PhysOrg.com) -- Peering far beyond our solar system, NASA researchers have detected the basic chemistry for life in a second hot gas planet, advancing astronomers toward the goal of being able to characterize ...
ACS podcast: Grow a garden on your roof to battle climate change
Oct 19, 2009 |
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"Green" roofs, those increasingly popular urban rooftops covered with plants, could help fight global warming, scientists in Michigan report in the latest episode in the American Chemical Society's (ACS) award-winning podcast ...
