carbon dioxide

American  

[kahr-buhn dahy-ok-sahyd] / ˈkɑr bən daɪˈɒk saɪd /

noun

1. a colorless, odorless, incombustible gas, CO 2 , present in the atmosphere and formed during respiration, usually obtained from coal, coke, or natural gas by combustion, from carbohydrates by fermentation, by reaction of acid with limestone or other carbonates, or naturally from springs: used extensively in industry as dry ice, or carbon dioxide snow, in carbonated beverages, fire extinguishers, etc.

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carbon dioxide British  

noun

1. Also called: carbonic-acid gas.  a colourless odourless incombustible gas present in the atmosphere and formed during respiration, the decomposition and combustion of organic compounds, and in the reaction of acids with carbonates: used in carbonated drinks, fire extinguishers, and as dry ice for refrigeration. Formula: CO 2

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carbon dioxide Scientific  

1. A colorless, odorless gas that is present in the atmosphere and is formed when any fuel containing carbon is burned. It is breathed out of an animal's lungs during respiration, is produced by the decay of organic matter, and is used by plants in photosynthesis. Carbon dioxide is also used in refrigeration, fire extinguishers, and carbonated drinks. Chemical formula: CO ₂ .

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carbon dioxide Cultural  

1. A compound made up of molecules containing one carbon atom and two oxygen atoms.

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Discover More

Carbon dioxide is normally found as a gas that is breathed out by animals and absorbed by green plants. The plants, in turn, return oxygen to the atmosphere. (See carbon cycle and respiration.)

Carbon dioxide is also given off in the burning of fossil fuels (see greenhouse effect).

Etymology

Origin of carbon dioxide

First recorded in 1870–75

Compare meaning

How does carbon-dioxide compare to similar and commonly confused words? Explore the most common comparisons:

• carbon monoxide vs. carbon dioxide

Example Sentences

The agency decided that six key planet-warming greenhouse gases, including carbon dioxide and methane, were a danger to human health.

From BBC

Climate modeling suggests that with a denser atmosphere rich in carbon dioxide, the planet might trap enough heat to allow liquid water to exist.

From Science Daily

China's emissions of planet-warming carbon dioxide were "flat or falling" in 2025, analysis showed Thursday, but progress remains fragile and it is not yet clear that emissions have peaked.

From Barron's

Coal is relatively inexpensive to produce but is the dirtiest fossil fuel, releasing considerable particulate air pollution, sulfur dioxide and mercury, and nearly twice the planet-warming carbon dioxide as natural gas.

From Los Angeles Times

And it would place a broader suite of climate regulations in legal jeopardy, including limits on carbon dioxide from power plants and methane from oil and gas operations.

From Barron's