Definition

Noun: A heavy, odorless, colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis. It is the chemical compound carbon dioxide.

Usage

"CO2" is the chemical formula for carbon dioxide. It is used primarily in scientific, environmental, and technical contexts to refer to this specific gas. It is often discussed in relation to climate change, biology, and chemistry.

Examples

• The level of CO2 in the atmosphere is a major concern for climate scientists.
• During respiration, humans and animals exhale CO2.
• Plants absorb CO2 and release oxygen through the process of photosynthesis.

Advanced Usage

• "CO2 emissions": The release of carbon dioxide into the atmosphere, typically from burning fossil fuels.
  • The new policy aims to reduce CO2 emissions from industrial sources.
• "CO2 footprint" or "carbon footprint": A measure of the total amount of carbon dioxide produced directly and indirectly by human activities.
  • Flying less is one way to lower your personal CO2 footprint.

Variants and Related Words

• Carbon dioxide (n): The full name of the compound; synonymous with CO2.
• Carbon (n): The chemical element (C) that is a primary component of CO2.
• Greenhouse gas (n): A category of gases, including CO2, that trap heat in the Earth's atmosphere.

Synonyms

• Carbon dioxide
• Carbonic acid gas (a less common technical term)

Related Phrases

• "CO2 sequestration": The process of capturing and storing atmospheric carbon dioxide.
  • Researchers are studying new methods for CO2 sequestration.
• "CO2 concentration": The amount of carbon dioxide present in a given volume, such as in the atmosphere.
  • Measurements show a steady increase in atmospheric CO2 concentration.

Noun

1. a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis