The article evaluates the greenhouse gas (GHG) footprint of natural gas obtained from shale formations, focusing on methane emissions. Natural gas is primarily composed of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere during the well's lifetime. These methane emissions are at least 30% more than those from conventional gas and can be more than twice as great. Methane is a potent greenhouse gas with a global warming potential (GWP) that is much higher than carbon dioxide, especially over the first few decades after emission. The study finds that methane emissions dominate the GHG footprint of shale gas over a 20-year time horizon, contributing 1.4 to 3 times more than direct CO2 emissions. Over a 100-year horizon, the GHG footprint of shale gas is still 14% to 19% greater than conventional gas. Compared to coal, the GHG footprint of shale gas is at least 20% greater over a 20-year horizon and comparable over a 100-year horizon. The study also highlights the need for better regulation and technology to reduce methane emissions, which are currently not widely adopted by the industry. The authors conclude that shale gas, despite being promoted as a bridge fuel, may not effectively mitigate climate warming due to its significant GHG footprint.The article evaluates the greenhouse gas (GHG) footprint of natural gas obtained from shale formations, focusing on methane emissions. Natural gas is primarily composed of methane, and 3.6% to 7.9% of the methane from shale-gas production escapes to the atmosphere during the well's lifetime. These methane emissions are at least 30% more than those from conventional gas and can be more than twice as great. Methane is a potent greenhouse gas with a global warming potential (GWP) that is much higher than carbon dioxide, especially over the first few decades after emission. The study finds that methane emissions dominate the GHG footprint of shale gas over a 20-year time horizon, contributing 1.4 to 3 times more than direct CO2 emissions. Over a 100-year horizon, the GHG footprint of shale gas is still 14% to 19% greater than conventional gas. Compared to coal, the GHG footprint of shale gas is at least 20% greater over a 20-year horizon and comparable over a 100-year horizon. The study also highlights the need for better regulation and technology to reduce methane emissions, which are currently not widely adopted by the industry. The authors conclude that shale gas, despite being promoted as a bridge fuel, may not effectively mitigate climate warming due to its significant GHG footprint.