What is Greenhouse gas ?

Correct option is B

Correct Answer: (b) Gas that emits and absorbs infrared radiation

Explanation:
A greenhouse gas (GHG) is a gas that absorbs and emits infrared radiation in the Earth's atmosphere, contributing to the greenhouse effect. These gases trap heat within the atmosphere, preventing it from escaping into space, leading to global warming and climate change.

The major greenhouse gases include carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapor (H₂O), and fluorinated gases. Human activities such as burning fossil fuels, deforestation, and industrial processes significantly increase GHG levels, intensifying climate change.

Information Booster:
● Carbon dioxide (CO₂) is the most significant GHG, primarily released from fossil fuel combustion, deforestation, and industrial activities.
● Methane (CH₄) is a potent GHG, released from livestock digestion, landfills, and natural gas extraction.
● Nitrous oxide (N₂O) comes from agriculture, fertilizers, and industrial processes.
● Fluorinated gases (CFCs, HFCs, PFCs) are synthetic gases with high global warming potential (GWP).
● The Kyoto Protocol and Paris Agreement are international treaties aimed at reducing GHG emissions.

Additional Knowledge:

• (a) Gas that releases hydrogen: Incorrect; greenhouse gases do not release hydrogen.
• (c) Gas that absorbs carbon dioxide: Incorrect; GHGs trap heat, but they do not absorb CO₂. Instead, plants absorb CO₂ through photosynthesis.
• (d) Gas that releases oxygen: Incorrect; gases like oxygen (O₂) are essential for life but are not greenhouse gases.