What are major greenhouse gas emissions from electricity generation using coal?

• A. Methane is the dominant greenhouse gas; coal plants also emit NOx, SO2, and particulates; methane may be released during mining.
• B. No greenhouse gases are emitted from coal-fired electricity.
• C. CO2 is the dominant greenhouse gas; coal plants also emit NOx, SO2, and particulates; methane may be released during coal mining and handling, though less prominent in burning coal.
• D. Oxygen is the main emission.

Answer: (C)

The key idea is that CO2 is the largest greenhouse gas emitted when coal is used to generate electricity. When coal burns, its carbon combines with oxygen to form carbon dioxide, and this happens in large quantities, making CO2 the dominant greenhouse gas from coal-fired power. In addition to CO2, coal plants release nitrogen oxides, sulfur dioxide, and fine particulates as air pollutants that affect health and air quality (and have climate-related indirect effects). Methane, while a potent greenhouse gas, mainly comes from the mining and handling of coal (ventilation air in mines, methane released from coal seams), and is much less prominent during the burning process itself. So the best description is that CO2 is the primary greenhouse gas from coal electricity, with NOx, SO2, and particulates as co-emissions, and methane largely tied to mining activities.