One of the challenges with using natural gas as a bridge fuel is greenhouse gas emissions from methane leaks.

While natural gas burns cleaner than coal and oil, it is primarily composed of methane, a potent greenhouse gas. If methane leaks during extraction, transportation, or storage, it can offset the climate benefits of using natural gas over coal. Methane has a much higher global warming potential than CO2 in the short term, making its leakage a significant concern for those advocating for natural gas as a transitional fuel in the fight against climate change.