Which gas is highly variable and a strong greenhouse gas?

Which gas is highly variable and a strong greenhouse gas?

• A. Water Vapour
• B. Carbon Dioxide
• C. Methane
• D. Nitrous Oxide

Answer: (A)

The key idea is that water vapour varies greatly in space and time and is a powerful greenhouse gas because it traps infrared radiation. Its amount in the atmosphere changes with temperature, humidity, and weather patterns, since more evaporation occurs as air warms. This makes it highly variable: on hot days or in humid regions, there’s more water vapour, which enhances the greenhouse effect further. While other greenhouse gases like carbon dioxide, methane, and nitrous oxide are also important, they are more stable and well-mixed in the atmosphere, changing less abruptly over short timescales. Water vapour acts as a strong feedback that amplifies warming, driven by the air’s temperature and moisture conditions rather than by a single, fixed emission source.

The key idea is that water vapour varies greatly in space and time and is a powerful greenhouse gas because it traps infrared radiation. Its amount in the atmosphere changes with temperature, humidity, and weather patterns, since more evaporation occurs as air warms. This makes it highly variable: on hot days or in humid regions, there’s more water vapour, which enhances the greenhouse effect further. While other greenhouse gases like carbon dioxide, methane, and nitrous oxide are also important, they are more stable and well-mixed in the atmosphere, changing less abruptly over short timescales. Water vapour acts as a strong feedback that amplifies warming, driven by the air’s temperature and moisture conditions rather than by a single, fixed emission source.