Greenhouse gas — Science definition
Defined in 3 courses:
- A gas, such as water vapor, carbon dioxide, or methane, that absorbs and re-emits heat radiating from Earth's surface. (Earth & Space Science)
- A gas such as carbon dioxide, methane, or water vapor that absorbs and re-radiates heat, warming the lower atmosphere. (Life Science: Biology)
- A gas — such as carbon dioxide, methane, water vapor, or nitrous oxide — that absorbs and re-emits the infrared heat radiating from Earth's surface. (Physics & Environmental Science)
Where it is taught
- Climate & the Greenhouse Effect — Oceans, Carbon & Climate, Earth & Space Science, Grade 9
- Human Impact & Conservation — Ecosystems & Conservation Decisions, Life Science: Biology, Grade 10
- Climate Change — Pollution, Carbon & Climate Evidence, Physics & Environmental Science, Grade 12
In use
More greenhouse gas means more outgoing heat gets caught near the surface, and the result is global warming — the steady rise in Earth's average temperature measured over the past hundred-plus years.
Climate & the Greenhouse Effect
Layered on top is climate change, driven by the buildup of greenhouse gases.
Human Impact & Conservation
Questions using greenhouse gas
Problem 1
- Carbon dioxide
- Nitrogen
- Oxygen
- Argon
Answer and explanation
Carbon dioxide
Carbon dioxide absorbs and re-emits outgoing heat; nitrogen, oxygen, and argon make up most of the atmosphere but are not significant greenhouse gases.
Problem 2
- Nitrogen
- Oxygen
- Carbon dioxide
- Argon
Answer and explanation
Carbon dioxide
Carbon dioxide, methane and water vapour absorb infrared; nitrogen and oxygen largely do not.
Problem 3
- Argon (Ar)
- Carbon dioxide (CO2)
- Nitrogen (N2)
- Oxygen (O2)
Answer and explanation
Carbon dioxide (CO2)
Carbon dioxide absorbs and re-emits outgoing infrared heat and is released in huge quantities by burning fossil fuels; nitrogen, oxygen, and argon make up most of the atmosphere but do not trap heat this way.
Problem 4
- Methane
- Nitrogen (N2)
- Water vapor
- Carbon dioxide
Answer and explanation
Nitrogen (N2)
Nitrogen makes up most of the atmosphere but does not absorb outgoing heat the way carbon dioxide, methane, and water vapor do.
Taught alongside
- climate
- greenhouse effect
- global warming
- biodiversity
- habitat fragmentation
- invasive species
- sustainability
- conservation
- fossil fuel
- carbon cycle
- climate feedback