Researchers from the Environmental Defense Fund, Princeton University, Rochester Institute of Technology, and Duke University have published an important paper that underlines again how important cutting methane leakage rates is for the global future of natural gas over the next 20 years.
The paper finds that replacing coal with natural gas does produce climate benefits during all time frames, but finds that the climate benefit is uncertain of switching from gasoline or diesel to natural gas.. Specifically the researchers find that methane leakage rates would have to be 1.6% for CNG cars to produce immediate as well as long-term climate benefits.
For CNG cars to have immediate climate benefits and not just long-term benefits, the paper states leakage rates would have to be cut 45% from assumed current levels to reach 1.6%. Some other experts think the leakage rates are near1.6% now, and this disagreement about current leakage rates drives home the need for more data.
The authors of this paper themselves raise their voices in support of more data on current leakage rates and note the good news that more data is now being collected that should start to clarify current leakage rates. Wisdom, however, counsels renewed efforts to cut methane leakage rates, no matter the current number.
The paper also innovates by producing a tool that it calls "Technology Warming Potential" TWP, a refinement of the IPCC's Global Warming Potential (GWP).
Cutting leakage rates can sharply reduce the carbon footprint of natural gas. Some in the gas industry don't accept climate science, and those may be tempted to just ignore this literature. That would be a big mistake for the future of natural gas in the next 20 years.
Others in the gas industry do indeed accept climate science and understand how central the methane leakage issue is becoming to public and governmental acceptance of natural gas around the world. This "EDF" paper is a contribution to sensible thinking and action on the topic, though the authors themselves raise their voices in support of more data on current leakage rates.