However, not all humans produce flatus that contains methane.

The oil contained approximately 40% methane by weight, compared to about 5% found in typical oil deposits.

Global Warming Energy companies have known since the 1920's that coal layers contain methane, often in large concentrations.

The early atmosphere contained carbon dioxide, methane and nitrogen, but almost no oxygen.

A third team of scientists has now reported a seemingly simple discovery on Mars: its atmosphere contains methane.

Jenkem also contains methane, which is explosive and flammable.

Its atmosphere contains hydrogen, helium and methane.

Even among humans whose flatus does contain methane, the amount is in the range of 10% or less of the total amount of gas.

However the coal in this seam was known to contain methane making it a very dangerous working environment.

Landfill gas is a complex mixture that mainly contains methane and CO2.