Correct Option (D)
According to theUnited States Environmental Protection Agency (EPA), power plants utilizing fossil fuels, particularlycoal and oil, are identified as thelargest source of sulfur dioxide (SO₂) emissions. Thecombustion of sulfur-containing fossil fuelsfor energy generation is the primary mechanism for SO₂ production.Coal-fired power plantscontribute significantly to these emissions, especially when high-sulfur coal is used without effectiveflue-gas desulfurization systems. The substantial volume of fossil fuel consumption, the widespread presence of such plants, and historical data consistently point to this sector as thedominant contributor to SO₂ pollution.
Incorrect Options
-
1. Locomotives using fossil fuels: While locomotives, particularly diesel-powered ones, emit SO₂, their contribution is considerably less significant compared to emissions from large-scale power generation facilities.
-
2. Ships using fossil fuels: Marine vessels, especially those historically using high-sulfur bunker fuels, contribute to SO₂ emissions. However, their overall contribution remains smaller than that of power plants. Furthermore, international regulations like IMO 2020 have significantly reduced the permissible sulfur content in marine fuels, thereby lowering their relative impact.
-
3. Extraction of metals from ores: Industrial processes such as smelting for metal extraction (e.g., copper or nickel) do release SO₂. These emissions are generally classified under smaller industrial sources and do not collectively represent the largest source compared to fossil fuel-based power generation.