Compared to gasoline and diesel fuel, natural gas is definitely cleaner, and it’s fairly convenient to use in the same engines that fun liquid fuels, but what about lifecycle emissions?
Thanks to hydraulic fracturing (fracking) and quick-and-dirty business practices, not to mention the near-absence of regulation, natural gas is booming in many parts of the world. As a fossil fuel, natural gas does generate fewer emissions than other fossil fuels, about 50% less carbon dioxide and about 66% fewer nitrogen oxides, but that’s not the whole story. For example, for every kilogram of natural gas that actually gets burned in an internal combustion engine, there is at least some percentage that never made it. One scientist estimates that natural gas leaking from wells could amount to 8% of production, while industry professionals estimate between 1% and 3% losses.
One story we covered pointed out that fracking methane emissions were found to be up to 14 g/s/km2 (grams per second per square kilometer, 204% higher than EPA estimates for the same region. Additionally, there are losses every time natural gas is moved from one container to another, through pipelines, during storage, and when put into cars, trucks, and other end-use containers. As a greenhouse gas, methane being the principal component, natural gas has about twenty times the greenhouse potential of carbon dioxide, which means any emissions “saved” by burning natural gas could be easily canceled out by just extracting natural gas.
Finally, there are all the emissions from fracking itself, aside from leakage, including well-boring machinery, site equipment, extraction and compression pumps, and transportation. All of this equipment uses fossil fuels to function, generating tons of carbon dioxide emissions, and almost none of it is powered by natural gas.