There is a Carbon Footprint if a process releases:
1.Carbon dioxide (CO2)
2.Methane (CH4)
3.Nitrous oxide (N2O)
4.Hydro fluorocarbons (HFCs)
Choose the correct option from the codes given below:

Answer: [D] 1, 2, 3 & 4

Carbon footprint considers all six of the Kyoto Protocol greenhouse gases listed above. However, to simplify matters- and since C02 is the most prevalent GHG-these emissions are expressed in terms of C02 equivalent based on a conversion table that uses the Intergovernmental Panel on Climate Change (IPCC) Global Warming Potential (GWP) factors.

This question is a part of GKToday's Integrated IAS General Studies Module