Carbon neutral is essentially shorthand for doesn't contribute to climate change. Methane (a) contains carbon and (b) is a much more potent greenhouse gas than CO2.

> More potent

Only in the short term.

Not that short-term.

Methane has a GWP (Global Warming Potential or equivalent impact compared to same amount of carbon dioxide) of 86 over 20 years; 34 over 100 years; and 7.6 over 500 years.

https://en.wikipedia.org/wiki/Global_warming_potential

That's very misleading.

34 / 5 is 6.8 so most of that 500 year potential is front loaded to the first 100 years. The difference from 7.6 vs 6.8 is because it breaks down into some CO2. And in fact is less potent than C02 from year 100-400.

Methane is a carbon compound.