Before our towns and homes were lit by electricity, we relied on something called town gas for everything from reading lights to cooking. Eventually, town gas in most places was replaced by natural gas, which burned cleaner. But the switch from town gas to natural gas was not a one to one replacement, and it was not trivial. Because town gas, unlike natural gas, is mostly hydrogen.

Closing the Gap is hosted by Gwen Holdmann and produced by Jennifer Pemberton. Music is from Blue Dot Sessions.