The ozone layer of the upper atmosphere is being destroyed by : 

1. Sulphur dioxide

2. Carbon dioxide

3. Chlorofluorocarbon

4. Smog

The phenomenon in which atmospheric gases trap the heat radiations from the sun near the earth’s surface and keeps it warm is known as-

1. Natural greenhouse effect

2. Tyndall effect

3. Heating effect

4. Joule’s effect

CO gas is more dangerous than CO₂ gas because : 

1. CO is capable of forming a complex with haemoglobin (carboxyhemoglobin), that is more stable than the oxygen-haemoglobin complex. 

2. CO is capable of forming a complex with haemoglobin (carboxyhemoglobin), that is less stable than the oxygen-haemoglobin complex. 

3. CO₂ is capable of forming a complex with haemoglobin (carboxyhemoglobin), that is more stable than the oxygen-haemoglobin complex. 

4. CO₂ is capable of forming a complex with haemoglobin (carboxyhemoglobin), that is less stable than the oxygen-haemoglobin complex. 

Gases responsible for greenhouse effect are : 
1. Carbon dioxide (CO₂)
2. Ozone (O₃)
3. Nitrous oxide (N₂O)
4. All of the above.

... is not a greenhouse gas :-
1. Hydrogen
2. Carbon dioxide
3. Methane
4. Nitrous oxide or $N_{2}O$

A non-greenhouse gas is : 
1. CO₂
2. CH₄
3. Chlorofluorocarbons
4. O₂

In the absence of greenhouse gases -

Tropospheric pollution arises due to the presence of:

Among the following gases, the one that is not a greenhouse gas is :

1. CO

2. O₃ 

3. CH₄

4. H₂O vapor

Among the following, the one that is not a greenhouse gas is:

1. Sulphur dioxide

2. Nitrous oxide

3. Methane

4. Ozone