Which of the following have the largest amount of Life Cycle greenhouse gas emissions when generating electricity?

Fossil fuel-based power sources, such as Coal and Natural Gas, produce the most greenhouse gas emissions when generating electricity. These sources emit carbon dioxide, methane, and other pollutants that can trap heat in the atmosphere and contribute to global warming. Coal is currently the leading source of electricity production in the United States but is also responsible for the most greenhouse gas emissions of any power source. Natural gas is the second-leading source of electricity generation and also contributes a significant amount of greenhouse gas emissions.