Consider the following :
- 1.Carbon monoxide
- 2.Methane
- 3.Ozone
- 4.Sulphur dioxide
Which of the above are released into atmosphere due to the burning of crop/biomass residue?
Show answer
Answer: D. Burning crop residue releases carbon monoxide, methane and sulphur dioxide directly, along with nitrogen oxides and volatile organic compounds. Ozone is not given off directly, but it forms near the ground when these gases react in sunlight. So all four end up in the air because of residue burning.
Watch for: Students think ozone is only a protective layer high up, not a pollutant formed from burning emissions.
Why the other options are wrong
- A. Wrong because ozone and sulphur dioxide are also produced.
- B. Wrong because carbon monoxide is a major product of incomplete burning.
- C. Wrong because methane and ozone are also produced.
Source to check: Central Pollution Control Board material on crop residue burning; Ministry of Agriculture, National Policy for Management of Crop Residues (2014)
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.