Why does geothermal power have lower greenhouse gas emissions than coal or natural gas power?

Geothermal power produces significantly lower greenhouse gas emissions than coal or natural gas because it does not rely on the combustion of fossil fuels as its primary energy source.12

While coal and natural gas power plants generate electricity by burning fuels—a process that releases large quantities of carbon dioxide and other pollutants into the atmosphere—geothermal plants harness the natural internal heat of the Earth. In most geothermal designs, the energy is captured from underground reservoirs of steam or hot water to drive turbines.3214

Some geothermal technologies, such as flash steam or enhanced geothermal systems (EGS), may require small energy inputs—often from fossil fuels—during construction or operation, which can result in minor greenhouse gas emissions. However, these emissions remain significantly lower than those produced by the continuous combustion required in coal or natural gas power generation. By utilizing a renewable heat source, geothermal energy serves as a cleaner alternative that helps mitigate the climate crisis.152