Methane, CH4, is a chemical compound composed of one carbon atom and four hydrogen atoms. It is one of the most common gases in the universe, as well as on Earth. While it is valued for its energy-production capabilities, methane also has the ability to potentially wreak havoc on the Earth's fragile ecosystems. Therefore, the gas has properties that are both good and bad.
This gas is a type of alkane, which are compounds composed only of carbon and hydrogen atoms in various numbers. In fact, methane is the simplest form of alkane. Despite the smells that some may be tempted to associate with the gas, it is odorless and colorless. Its simplicity may be partly responsible for its proliferation in many different places and settings, and many lifeforms produce some amount of methane.
Wetlands and oceans are where most of the Earth's natural methane is produced. Thus, the gas is sometimes called swamp gas. Approximately 40% of the world's methane is produced through these areas. However, most of the rest comes from human sources, such as burning fuel and raising livestock.
Interestingly, some plants and animals produce methane through aerobic processes and others do not, studies have shown. In fact, variations can even be found within species. For example, it is reported that 1/3 of people may produce methane, but the rest do not. There is no universally-accepted explanation for this.
Methane used as energy comes mainly in the form of natural gas. It is taken out of the Earth's crust from huge natural stores called natural gas fields. Once extracted, it may be transported, by container or by pipeline to other areas around the globe.
While methane, in and of itself, is considered a harmless gas, scientists have listed it as a very potent greenhouse gas and it may have a major role in global warming. Given this consideration, many are seeking ways to limit its emission. These emissions have doubled since the Industrial Revolution more than 100 years ago and many scientists believe there is a directl correlation between the increase and global temperatures.
In addition to natural gas-fired electrical generation stations, there are other uses for methane as an energy source as well. It is currently being used to power some automobiles and NASA is considering its use as a fuel for space vehicles. If the technology can be developed, it is envisioned that the gas could be harvested from other places in the solar system to give such vehicles enough fuel to travel much greater distances than they may otherwise be able to go.