Q. Consider the following statements regarding carbon dioxide, methane, and nitrous oxide:

1. They are greenhouse gases.
2. They are produced by cattle.
3. They are used in carbonated drinks.
4. They are inorganic gases.

Which of the above statements is / are correct?
Answer: Only 1 and 4
Notes: Carbon dioxide, methane, and nitrous oxide are all greenhouse gases as identified by the Kyoto Protocol. Only carbon dioxide is used in carbonated drinks, not methane or nitrous oxide. Of the three, only carbon dioxide is inorganic; methane and nitrous oxide are typically classified as organic. All three may be emitted by cattle, but not all are used in drinks or are inorganic.