Question

What is the common chemical property of greenhouse (GH) gases that cause them to absorb IR (infrared irradiation)? Name a few GH gases. Explain why CO2 has been considered the most important greenhouse gas that may cause climate change, although many of the greenhouse gases have IR absorption efficiency much stronger than CO2? (Maximum 250 words)

Answer 1

The common chemical property of green house gases is formation of blanketing layer over the Earth's surface with the help of water vapour present in atmosphere and absorb IR radiation coming from the Earth's surface and reflect them back to the Earth's surface. Due to this the Earth's surface gets heated up. This phenomenon is called Green House Effect (GHE) or Global Warming.

The important green house gases are

1) Carbon dioxide (CO2) - 50%

2) Methane (CH4) - 19%

3) Chlorofluorocarbons (CFC) - 17%

4) Ozone (O3) - 8%

5 Nitric oxide (NO) - 4%

6) Water vapour (H2O) - 2%

Among all the carbon dioxide plays major role in green house effect because it is major component for this effect.

It is released in to the atmosphere due to incomplete combustion of fossil fuels like natural gas, coal and petroleum products.

It is heavier than air

If deforestation takes place, oxygen imbalance occurs and CO2 levels in atmosphere increases. This leads to GHE.