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
Cuts in greenhouse gas emissions would save Arctic ice, reduce sea level rise
Space & Earth / Earth Sciences
Apr 14, 2009 |
4.6 / 5 (88) |
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The threat of global warming can still be greatly diminished if nations cut emissions of heat-trapping greenhouse gases by 70 percent this century, according to a new analysis. While global temperatures would ...
Increasing carbon dioxide and decreasing oxygen make it harder for deep-sea animals to 'breathe'
Space & Earth / Earth Sciences
Apr 17, 2009 |
4.8 / 5 (78) |
7
(PhysOrg.com) -- New calculations made by marine chemists from the Monterey Bay Aquarium Research Institute (MBARI) suggest that low-oxygen "dead zones" in the ocean could expand significantly over the next ...
EPA closer to global warming warning (Update)
Mar 23, 2009 |
4.6 / 5 (79) |
5
(AP) -- The Environmental Protection Agency has taken the first step on the long road to regulating greenhouse gases under the Clean Air Act.
Forests could flip from sink to source of CO2: study
Apr 17, 2009 |
4.7 / 5 (78) |
12
Forests that today soak up a quarter of carbon pollution spewed into the atmosphere could soon become a net source of CO2 if Earth's surface warms by another two degrees Celsius (3.6 degrees Fahrenheit), cautions ...
EPA finds greenhouse gases pose a danger to health
Apr 17, 2009 |
4.5 / 5 (75) |
9
(AP) -- The Environmental Protection Agency concluded Friday that greenhouse gases linked to climate change "endanger public health and welfare," setting the stage for regulating them under federal clean air laws.
Super-size deposits of frozen carbon threat to climate change
Space & Earth / Earth Sciences
Jun 30, 2009 |
4.7 / 5 (60) |
11
The vast amount of carbon stored in the arctic and boreal regions of the world is more than double that previously estimated, according to a study published this week.
House Democrats unveil sweeping plan to reshape energy in America
Apr 01, 2009 |
4.3 / 5 (62) |
21
Democrats in the House of Representatives on Tuesday announced a sweeping plan to change how the nation produces and uses energy in order to reduce the risk of dangerous climate change.
US announces new fuel economy standard for 2011
Mar 27, 2009 |
4.6 / 5 (57) |
6
The US administration Friday announced updated automobile fuel efficiency standards for new vehicles starting with the 2011 model year that aim to reduce gasoline consumption and emissions.
A new measure of global warming from carbon emissions
Jun 10, 2009 |
4.2 / 5 (57) |
13
Damon Matthews, a professor in Concordia University's Department of Geography, Planning and the Environment has found a direct relationship between carbon dioxide emissions and global warming. Matthews, together with colleagues ...
Last time carbon dioxide levels were this high: 15 million years ago, scientists report
Space & Earth / Earth Sciences
Oct 08, 2009 |
3.6 / 5 (63) |
137
You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science.
Global warming: Our best guess is likely wrong
Space & Earth / Earth Sciences
Jul 14, 2009 |
4.6 / 5 (49) |
54
No one knows exactly how much Earth's climate will warm due to carbon emissions, but a new study this week suggests scientists' best predictions about global warming might be incorrect.
To meet climate goal, only quarter of fossil fuels can be used: study
Apr 29, 2009 |
4.2 / 5 (53) |
17
Meeting a widely-supported goal to tackle global warming means that humanity will be able to burn less than a quarter of the proven reserves of fossil fuels by 2050, a study released on Wednesday said.
CO2 higher today than last 2.1 million years
Space & Earth / Earth Sciences
Jun 18, 2009 |
4.4 / 5 (49) |
28
Researchers have reconstructed atmospheric carbon dioxide levels over the past 2.1 million years in the sharpest detail yet, shedding new light on its role in the earth's cycles of cooling and warming.
Is global warming unstoppable?
Nov 23, 2009 |
3.6 / 5 (56) |
81
In a provocative new study, a University of Utah scientist argues that rising carbon dioxide emissions - the major cause of global warming - cannot be stabilized unless the world's economy collapses or society builds the ...
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.
