Final answer:
The option 'None of the above' is incorrect as all the mentioned sources can contribute to acid rain. Coal-burning power plants, lightning, and volcanic eruptions all release substances that can lower the pH of precipitation, resulting in acid rain.
Step-by-step explanation:
Answering the student's question, all of the provided options contribute to acid rain. This is because acid rain is rainwater with a pH of less than 5, which becomes acidic due to the dissolution of various nonmetal oxides such as CO2, SO2, SO3, NO, and NO₂. These pollutants can originate from different sources:
- Coal-burning power plants release sulfur oxides and other pollutants that form acids.
- Lightning can cause nitrogen molecules in the atmosphere to combine with oxygen to form nitrogen oxides, which are precursors to nitric acid in acid rain.
- Volcanic eruptions emit sulfur trioxide and other gases that can result in sulfuric acid in the atmosphere.
Among the options presented, the most significant anthropogenic causes of acid rain are emissions of sulfur dioxide and nitrogen oxides due to the combustion of fossil fuels, as seen in the emissions from coal-fired power plants and motor vehicles.
Regarding the consensus on global climate change, this is attributed largely to anthropogenic factors, particularly the emissions of greenhouse gases from human activities.