carbon cycle
noun
1
: the cycle of carbon in the earth's ecosystems in which carbon dioxide is fixed by photosynthetic organisms to form organic nutrients and is ultimately restored to the inorganic state (as by respiration, protoplasmic decay, or combustion)
2
: a cycle of thermonuclear reactions in which four hydrogen atoms synthesize into a helium atom by the catalytic action of carbon with the release of nuclear energy and which is held to be the source of most of the energy radiated by the sun and stars
Examples of carbon cycle in a Sentence
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These minerals suggest Mars may have once also had a functioning carbon cycle — similar to Earth's — where some of the carbon dioxide locked in rocks eventually made its way back into the atmosphere.
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Victoria Corless, Space.com, 21 Apr. 2025
According to a paper published on April 18 in Nature, ancient geologic samples indicate the Red Planet at one time featured a carbon cycle—an atmospheric condition that’s necessary for sustaining liquid water on the Martian surface.
—Andrew Paul, Popular Science, 17 Apr. 2025
Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars
A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine.
—Monica Cull, Discover Magazine, 17 Apr. 2025
When the long-standing oxygen plateau finally gave way to a surge in atmospheric and oceanic oxygen levels, this increase was fueled by a shift in microbial and algal activity, which ramped up photosynthesis and altered the carbon cycle.
—Scott Travers, Forbes.com, 30 Mar. 2025
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Victoria Corless, Space.com, 21 Apr. 2025
According to a paper published on April 18 in Nature, ancient geologic samples indicate the Red Planet at one time featured a carbon cycle—an atmospheric condition that’s necessary for sustaining liquid water on the Martian surface.
—Andrew Paul, Popular Science, 17 Apr. 2025
Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars
A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine.
—Monica Cull, Discover Magazine, 17 Apr. 2025
When the long-standing oxygen plateau finally gave way to a surge in atmospheric and oceanic oxygen levels, this increase was fueled by a shift in microbial and algal activity, which ramped up photosynthesis and altered the carbon cycle.
—Scott Travers, Forbes.com, 30 Mar. 2025
See All Example Sentences for carbon cycle
Cite this Entry
“Carbon cycle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/carbon%20cycle. Accessed 15 May. 2025.
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