Q.List gases which are responsible for greenhouse effect.

Greenhouse gases are those atmospheric gases that absorb and re-radiate infrared (heat) radiation reflected by the earth's surface, trapping heat within the atmosphere and warming the planet — a natural phenomenon called the greenhouse effect, which becomes a problem (global warming) when these gases accumulate in excess due to human activity.

The major greenhouse gases are:

• Carbon dioxide (CO2) — released by burning of fossil fuels (coal, petroleum, natural gas), deforestation and respiration; the single largest contributor to enhanced global warming.
• Methane (CH4) — released from paddy fields, wetlands, cattle (enteric fermentation), landfills and natural gas leakage; molecule-for-molecule a much stronger absorber of infrared radiation than CO2.
• Water vapour (H2O) — the most abundant natural greenhouse gas, increases as the atmosphere warms.
• Nitrous oxide (N2O) — released from the use of nitrogenous fertilisers and combustion processes.
• Ozone (O3) — a greenhouse gas in the troposphere (though it is protective in the stratosphere). …

Recall the standard list of greenhouse gases taught in the NCERT chapter and briefly note a source for …

• Omitting water vapour, which is actually the most abundant greenhouse gas.
• Confusing greenhouse gases with ozone-depleting substances — CFCs are actually both. …