Atmospheric Science

Choose the Correct Answer

Correct Answer : Option c

Explanation
Water vapor (H2O in gaseous form) is the most abundant greenhouse gas in the Earth’s atmosphere. Unlike carbon dioxide (CO2), methane (CH3), and nitrous oxide (N2O), which have direct anthropogenic sources, water vapor primarily enters the atmosphere through natural processes like evaporation from oceans, lakes, and soil, as well as plant transpiration.
Key Characteristics of Water Vapor:
● Most Potent Natural Greenhouse Gas: Water vapor traps heat more efficiently than CO2 and methane but has a shorter atmospheric lifespan.
● Temperature-Dependent: Its concentration varies with temperature, as warmer air holds more moisture, intensifying global warming.
● Influence on Weather & Climate: It plays a crucial role in cloud formation, precipitation, and storm dynamics, shaping climate patterns.
● Water Vapor Feedback Loop: Rising temperatures increase evaporation, adding more water vapor, which further enhances warming.

Statement 1 is correct: Water vapor is the most abundant greenhouse gas and enhances the natural greenhouse effect by trapping heat.

Statement 2 is not correct: Unlike CO2 and methane, water vapor is not directly emitted by human activities but is controlled by natural processes like evaporation.

Statement 3 is correct: The atmospheric water vapor content depends on temperature, as warmer air can hold more moisture.

Statement 4 is correct : Water vapor plays a key role in cloud formation, precipitation, and overall climate regulation.