Not just "the belly of inner earth" renewing natural gas sources...

Not just "the belly of inner earth" renewing natural gas sources Elee; there is also Biogas which is Renewable Natural Gas in the form of almost pure Methane.

Biogas

Raw Renewable Natural Gas, gathered from farms and landfills, is methane, which the fuel industry calls biogas. In order to be usable in vehicles or homes, purified methane must be packaged under pressure to make it usable as a fuel. This pressurized product is called Compressed Natural Gas (CNG).

What's the difference between natural gas and methane?

Natural gas is almost pure methane, currently sourced from raw, fossil natural gas produced from deposits deep underground. But methane could come from renewable resources, too. Two main methane sources could be used to make RNG.

What percentage of Rng is methane in natural gas?

Typically, RNG injected into a natural gas pipeline has a methane content between 96 and 98 percent. Read more about RNG in EPA’s resource An Overview of Renewable Natural Gas from Biogas.