Where Does Natural Gas Come From?
Natural gas is believed to be formed from the remains of ancient plants that lived in the shallow seas that once covered much of the earth. Many layers of the decayed plant matter became buried beneath the earth’s surface, and very slowly changed into natural gas.
The rocks that hold natural gas are porous, or full of tiny holes, and the holes contain the gas. When shafts are drilled into the rock, gas seeps out of the holes and into the shafts. From the wells, the gas travels long distances through pipes, to be stored in huge tanks near places where the gas is to be used.
Natural gas is a nonrenewable resource because it cannot be replenished on a human time frame. It is an energy source often used for heating, cooking, and electricity generation. It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals.
Natural gas is often informally referred to simply as “gas”, especially when compared to other energy sources such as oil or coal. However, it is not to be confused with gasoline, especially in North America, where the term gasoline is often shortened in colloquial usage to gas.
Based on an estimated 2015 world consumption rate of about 3.4 trillion cubic meters of gas per year, the total estimated remaining economically recoverable reserves of natural gas would last 250 years at current consumption rates.
An annual increase in usage of 2–3% could result in currently recoverable reserves lasting significantly less, perhaps as few as 80 to 100 years.