Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide[1]. It is found in oil fields and natural gas fields, and in coal beds. When methane-rich gases are produced by the anaerobic decay of non-fossil organic material, these are referred to as biogas. Sources of biogas include swamps, marshes, and landfills (see landfill gas), as well as sewage sludge and manure by way of anaerobic digesters, in addition to enteric fermentation particularly in cattle. Natural gas is often informally referred to as simply gas, especially when compared to other energy sources such as electricity. Before natural gas can be used as a fuel, all the materials other than methane have to be removed in a process called sweetening. The removed paraffins and the helium all have commercial applications and are sold on as by-products of the sweetening process

Methane is a significant and plentiful fuel which is the principal component of natural gas. Burning one molecule of methane in the presence of oxygen releases one molecule of CO2 (carbon dioxide) and two molecules of H2O:

CH4 + 2O2 → CO2 + 2H2O

Methane's relative abundance and clean burning process makes it a very attractive fuel. However, because it is a gas (at normal temperature and pressure) and not a liquid or solid, methane is difficult to transport from the areas that produce it to the areas that consume it. Converting methane to derivatives that are more easily transported, such as methanol, is an active area of research. Certain microorganisms can effect this selective oxidation using enzymes called methane monooxygenases.

Methane is a relatively potent greenhouse gas with a global warming potential.[1] When averaged over 100 years each kg of CH4 warms the Earth 23 times as much as the same mass of CO2.

The Earth's crust contains huge amounts of methane. Large amounts of methane are produced by methanogenesis. Other sources include mud volcanoes which are connected with deep geological faults.

Sorry Earthling, the two are not the same...

Again I ask, why not find a way to make a methane burning mode of transportation?