How does natural gas compare to coal in CO2 emissions per unit of electricity generated?

• A. Natural gas emits substantially less CO2 per kWh than coal—roughly 40–50% lower, depending on plant efficiency.
• B. Natural gas emits more CO2 per kWh than coal.
• C. Natural gas and coal emit about the same CO2 per kWh.
• D. Natural gas emits 70% less CO2 per kWh.

Answer: (A)

Natural gas generally produces less CO2 per unit of electricity than coal because it has a lower carbon content per unit of energy and because gas-fired plants—especially modern combined-cycle units—operate at higher thermal efficiency than many coal plants. This means you burn less fuel to generate the same amount of electricity, and each unit of fuel releases less CO2. Taken together, this typically yields about 40–50% lower CO2 emissions per kilowatt-hour for natural gas compared with coal, though the exact amount depends on the specific plant efficiency and technology.