Related topics: climate change , greenhouse gas , global warming , fossil fuels , carbon dioxide emissions
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
Global warming likely to be amplified by slow changes to Earth systems
Space & Earth / Earth Sciences
Dec 20, 2009 |
2.7 / 5 (41) |
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Researchers studying a period of high carbon dioxide levels and warm climate several million years ago have concluded that slow changes such as melting ice sheets amplified the initial warming caused by greenhouse ...
Potatoes, algae replace oil in US company's plastics
Dec 21, 2009 |
3.9 / 5 (17) |
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Frederic Scheer is biding his time, convinced that by 2013 the price of oil will be so high that his bio-plastics, made from vegetables and plants, will be highly marketable.
Researchers engineer bacteria to turn carbon dioxide into liquid fuel
Dec 10, 2009 |
4.7 / 5 (43) |
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(PhysOrg.com) -- The genetically modified cyanobacterium consumes carbon dioxide and produces the liquid fuel isobutanol by using energy from sunlight.
Soil Microorganisms? Role Cited as a Missing Factor in Climate Change Equation
Dec 17, 2009 |
3.4 / 5 (7) |
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(PhysOrg.com) -- Those seeking to understand and predict climate change can now use an additional tool to calculate carbon dioxide exchanges on land, according to a scientific journal article co-authored by a University of ...
Climate talks end with eye on next year
Dec 19, 2009 |
1.8 / 5 (5) |
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(AP) -- A historic U.N. climate conference ended Saturday with only a nonbinding "Copenhagen Accord" to show for two weeks of debate and frustration. It was a deal short on concrete steps against global warming, ...
Replicating Climate Change to Forecast its Effects
Dec 17, 2009 |
2.5 / 5 (4) |
2
(PhysOrg.com) -- Agricultural Research Service (ARS) scientists are replicating the effects of climate change to see what the future holds for soybeans, wheat and the soils where they grow.
NASA, Google offer more precise emissions tracking
Dec 17, 2009 |
1 / 5 (1) |
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(AP) -- The question is a potential deal-killer: If nations ever agree to slash greenhouse gas emissions, how will the world know if they live up to their pledges?
New results from a terra-ific decade in orbit
Space & Earth / Earth Sciences
Dec 15, 2009 |
5 / 5 (1) |
0
December 18, 2009, marks the tenth year since the launch of Terra, one of NASA's "flagship" Earth observing satellites. But the decade is more than just a mechanical milestone. With each additional day and ...
Machine Converts CO2 into Gasoline, Diesel, and Jet Fuel
Nov 23, 2009 |
4.4 / 5 (45) |
25
(PhysOrg.com) -- Researchers at Sandia National Laboratories have built a machine that uses the sun's energy to convert carbon dioxide waste from power plants into transportation fuels such as gasoline, diesel, ...
NASA Calculates a Carbon Budget for California
Dec 16, 2009 |
2.8 / 5 (9) |
6
(PhysOrg.com) -- While world organizations struggle to find a benchmark and tracking standards for greenhouse gas (GHG) emissions, NASA has been supporting California’s new carbon emissions inventory report, using its satellite ...
Oceans' Uptake of Manmade Carbon May Be Slowing
Space & Earth / Earth Sciences
Dec 09, 2009 |
3.5 / 5 (20) |
10
(PhysOrg.com) -- The oceans play a key role in regulating climate, absorbing more than a quarter of the carbon dioxide that humans put into the air. Now, the first year-by-year accounting of this mechanism ...
Study: Earth more sensitive to carbon dioxide than previously thought
Space & Earth / Earth Sciences
Dec 06, 2009 |
3.1 / 5 (51) |
91
In the long term, the Earth's temperature may be 30-50% more sensitive to atmospheric carbon dioxide than has previously been estimated, reports a new study published in Nature Geoscience this week.
NASA Outlines Recent Breakthroughs in Greenhouse Gas Research (w/ Video)
Space & Earth / Earth Sciences
Dec 15, 2009 |
3.7 / 5 (6) |
1
(PhysOrg.com) -- Researchers studying carbon dioxide, a leading greenhouse gas and a key driver of global climate change, now have a new tool at their disposal: daily global measurements of carbon dioxide ...
A greener way to get electricity from natural gas
Dec 03, 2009 |
3.7 / 5 (16) |
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(PhysOrg.com) -- A new type of natural-gas electric power plant proposed by MIT researchers could provide electricity with zero carbon dioxide emissions to the atmosphere, at costs comparable to or less than ...
Blood Enzyme Could Help Realize Clean Coal
Dec 03, 2009 |
4.2 / 5 (6) |
0
(PhysOrg.com) -- An enzyme in our blood that enables our lungs to exhale carbon dioxide could be the key to isolating carbon dioxide emissions from coal plants in order to store them safely underground. A ...
