carbon dioxide: Quick Facts

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Oct. 22, 2026

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Facts

Also Known As	fixed air

Photos and Videos

Diagram of a tree leaf illustrating photosynthesis, with arrows showing sunlight, water, and carbon dioxide entering the leaf and sugars and oxygen being produced. A person is shown beside the tree to demonstrate the exchange of oxygen and carbon dioxide between plants and animals.

Rutherford, Daniel

Diagram showing the process of cellular respiration, where glucose and oxygen are converted into carbon dioxide and water, with energy released as indicated by red arrows. The chemical equation C6H12O6 plus 6O2 yields 6CO2 plus 6H2O is displayed.

Figure 17: Changes in the global mean temperature expected due to past and anticipated variations in trace atmospheric gases. (Top) Increases in greenhouse forcing per decade from 1850 through the mid-1980s. (Bottom) Decadal increments of greenhouse forcing projected for the period from 1990 to 2030.

Line graph showing the Keeling Curve, which tracks atmospheric carbon dioxide (CO2) levels at Mauna Loa from 1965 to 2025. The graph shows a steady upward trend from about 320 to over 420 parts per million, with seasonal fluctuations. An inset highlights the annual cycle of CO2, demonstrating both the short-term oscillations and the long-term increase.

carbon dioxide: global warming scenarios

Infographic showing a timeline of major climate change milestones from 1896 to 2025, with key events listed on the left. Insets on the right display a graph of rising atmospheric carbon dioxide levels, diagrams of ocean acidification due to carbon dioxide, and a world map highlighting countries that have signed or ratified the Paris Agreement.

Diagram of the glyoxylate cycle showing the metabolic pathway steps, with arrows indicating the flow between compounds such as acetate, acetyl S-CoA, citrate, isocitrate, glyoxylate, succinate, and malate. CO2 release and biosynthesis branches are highlighted.

Figure 9: Oxidation path for methane, CH4.

Understand the carbon and oxygen cycles in the atmosphere

How a candle flame burns

The impact of human activities on climate change

How greenhouse gases affect Earth's climate

The Relationship Between Photosynthesis and Breathing

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Topics

Ocean Acidification: How Carbon Dioxide Is Hurting the Seas Do cows pollute as much as cars?Greenhouse gas decarbonization Carbon footprint Keeling Curve Carbon offset Dry ice carbonic acid carbon tax carbide Carbon monoxide carbonate

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Key People

Joseph Black, detail of an engraving by J. Rogers after a portrait by Sir Henry Raeburn

Joseph Black

British scientist

Helmont, Jan Baptista van

Jan Baptista van Helmont

Belgian scientist

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Gerard Peter Kuiper

American astronomer

Model of a molecule. Atom, Biology, Molecular Structure, Science, Science and Technology. Homepage 2010 arts and entertainment, history and society

Science Quiz

Combination shot of Grinnell Glacier taken from the summit of Mount Gould, Glacier National Park, Montana in the years 1938, 1981, 1998 and 2006.

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