Natural gas, like coal and oil, is a fossil fuel. In all combustion of fossil fuels, carbon dioxide is generated which amplifies the greenhouse effect. How much carbon dioxide is formed depends mainly on how many carbon atoms the fuel contains per unit of energy.
Natural gas contains fewer carbon atoms per unit of energy than oil and coal. Therefore, natural gas contributes less to the greenhouse effect. Natural gas emits almost 40 percent less carbon dioxide than coal and 25 percent less than oil.
Emissions of other substances, such as heavy metals, sulfur, nitrogen oxides, dust, and soot, are significantly lower from natural gas compared to coal and oil.