International standard about uses of natural gas as alternative fuel?

Question

International standard about uses of natural gas as alternative fuel?

Answer 1

Natural gas is the way to go. It has been used as a fuel source since the late 1700's.  

  Like all gasses it has to be liquefied to equal the output of regular gas but has one advantage. It’s by products are CO2 and Water. Since Almost every combustion engine can run on natural gas with little modification and the majority of  large factory type combustion engines (CAT, Hyundai,  Honda,  Ford, Etc)  actually have had models out that are LPG (natural gas) since the 1940’s  the standard has been left up to the manufacture’s and how they want you to run their engine. These companies look not just at their bottom dollar. But the cost to you for running them if it is going to be expensive for you to run then why would you buy their model?

Answer 2

You do realize that we are already running out of Natural Gas, right? So it isn't really an alternative fuel in the sense that it can replace oil.