Methane, an invisible, odorless gas that makes up more than 95% of natural gas fuel, can be as much as 80 times more potent as a global warmer per given unit than CO2, which is more plentiful in the atmosphere. While there are less emissions than CO2, methane lasts around 12 years, while CO2 lingers for centuries.
2020 April 7, John Fialka, “As CO2 Emissions Drop During Pandemic, Methane May Rise”, in Scientific American