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
SFU creates portable extreme environment
18 hours ago |
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(PhysOrg.com) -- A Simon Fraser University lab's invention will make it easier for researchers to travel anywhere to study how extreme environments affect various populations, including the elderly, athletes and the sick.
Soil contributes to climate warming more than expected
Feb 09, 2010 |
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The climatic warming will increase the carbon dioxide emissions from soil more than previously estimated. This is a mechanism that will significantly accelerate the climate change. Already now the carbon dioxide emissions ...
Biologist solves mystery of tropical grasses' origin
Feb 08, 2010 |
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Around 30 to 40 million years ago, grasses on Earth underwent an epic evolutionary upheaval. An assemblage capitalized on falling levels of atmospheric carbon dioxide by engineering an internal mechanism to concentrate the ...
Understanding past and future climate
Space & Earth / Earth Sciences
Feb 05, 2010 |
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The notion that scientists understand how changes in Earth's orbit affect climate well enough for estimating long-term natural climate trends that underlie any anthropogenic climate change is challenged by findings published ...
Cyber fraudsters attack EU's carbon trading system
Feb 04, 2010 |
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Online fraudsters have carried out a "widepread" cyber attack on the European Union's Emissions Trading Scheme (ETS), the EU commission said Thursday, promising a security review.
Oceans reveal further impacts of climate change, says UAB expert
Feb 04, 2010 |
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The increasing acidity of the world's oceans - and that acidity's growing threat to marine species - are definitive proof that the atmospheric carbon dioxide that is causing climate change is also negatively ...
According to new survey, Americans support strong climate, energy policies
Feb 04, 2010 |
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Despite a sharp drop in public concern over global warming, Americans—regardless of political affiliation—support the passage of federal climate and energy policies, according to the results of a national survey released ...
Black carbon a significant factor in melting of Himalayan glaciers
Space & Earth / Earth Sciences
Feb 03, 2010 |
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The fact that glaciers in the Himalayan mountains are thinning is not disputed. However, few researchers have attempted to rigorously examine and quantify the causes. Lawrence Berkeley National Laboratory ...
Enlisting a drug discovery technique in the battle against global warming
Feb 03, 2010 |
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Scientists in Texas are reporting that a technique used in the search for new drugs could also be used in the quest to discover new, environmentally friendly materials for fighting global warming. Such materials ...
New study reveals 'red hot' results
Feb 02, 2010 |
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A new weight-loss supplement tested by the University of Oklahoma Health and Exercise Science Department has the potential to burn as many calories as a 20-minute walk, according to Joel T. Cramer, assistant professor of ...
Stratospheric Water Vapor is a Global Warming Wild Card
Space & Earth / Earth Sciences
Jan 28, 2010 |
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A 10 percent drop in water vapor ten miles above Earth’s surface has had a big impact on global warming, say researchers in a study published online January 28 in the journal Science. The findings might help e ...
Study Fumes Over City Park Grass
Jan 28, 2010 |
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Plants are usually our allies when it comes to reducing the atmosphere's greenhouse gases, converting carbon dioxide into food and storing the gas' carbon in the soil below.
Effects of forest fire on carbon emissions, climate impacts often overestimated
Jan 27, 2010 |
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A recent study at Oregon State University indicates that some past approaches to calculating the impacts of forest fires have grossly overestimated the number of live trees that burn up and the amount of carbon ...
Physicist counts bubbles in the ocean to answer questions about climate, sound, light (w/ Video)
Jan 21, 2010 |
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The bubbles in your champagne that appear to jump out of your glass and tickle your nose are exhibiting a behavior quite similar to the tiny bubbles found throughout the world's oceans, according to bubble ...
USF Study Shows First Direct Evidence of Ocean Acidification
Space & Earth / Earth Sciences
Jan 20, 2010 |
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(PhysOrg.com) -- Seawater in a vast and deep section of the northeastern Pacific Ocean shows signs of increased acidity brought on by manmade carbon dioxide in the atmosphere -- a phenomenon that carries with ...
