Short answers, pulled from the story.
The New London Texas explosion in 1937 killed 294 people and forced the addition of a chemical odorant to natural gas. This tragedy occurred when an odorless and colorless natural gas leak ignited without warning. The disaster led to the legislative requirement to add thiophane or tert-butyl mercaptan to the gas supply.
The first commercial natural gas well was dug by William Hart in Fredonia New York in 1821. This event marked the beginning of the natural gas industry that would eventually dwarf coal and oil in global influence. Before long-distance pipelines were developed in the early 20th century gas was a local commodity used only near the source.
Natural gas is primarily composed of methane which accounts for 95% of its composition. It also contains small amounts of higher alkanes and traces of carbon dioxide nitrogen hydrogen sulfide and helium. When burned methane produces a characteristic blue flame that yields less soot and fewer toxic pollutants compared to other fossil fuels.
The world's largest gas field the offshore South Pars North Dome Gas-Condensate field is shared between Iran and Qatar. This field holds an estimated 50 trillion cubic meters of natural gas and 50 billion barrels of natural gas condensates. Russia has proven reserves of 47,600 cubic kilometers according to the US Central Intelligence Agency.
Hydraulic fracturing involves forcing water mixed with chemicals through wellbore casing into rock to release gas. Nearly 3 million gallons of water were used for horizontal gas wells between 2000 and 2010. The flowback water may contain radioactive materials heavy metals natural salts and hydrocarbons posing significant environmental and public health risks.
Floating liquefied natural gas technology enables the development of offshore gas resources that would otherwise remain untapped. Projects are underway to construct five FLNG facilities including Shell Prelude which is due to start production in 2017. Renewable natural gas also known as biomethane is a renewable fuel made from biogas that has been upgraded to a quality similar to fossil natural gas.