Scientists, industry, regulators struggle with the suspect math of natural gas leaks
Snaking beneath the surface of many Eastern cities is a network of aging, cast-iron pipes carrying natural gas. The pipes, buried underground, have been shifted for decades by winter freeze-thaw cycles, and some are simply cracked from age. Because of this, some pipes leak. Just how much gas from those older pipes and their newer replacements in the pipeline distribution system leaks out and rises into the atmosphere, though, is up for debate.