The creation of gas begins under the oceans. The dead remains of sea life sink to the bottom of ancient oceans. They build up between layers of sediment that are eventually buried at great depths. This dead sea life heats slowly over time. After millions of years it gets cooked under the sedimentary rock. This forms oil. When the oil is ‘overcooked’ it turns to gas. This is why most oil and gas fields are close together.
The biggest gas fields are in the Middle East and Russia. Most gas is transported by pipeline. Some is turned into liquid and moved by ship. Natural gas is odourless. An additive is included to give gas its distinctive smell.
Most of us use gas in our homes for heating and cooking. More and more cars are run on gas, which produces 30% less carbon dioxide when burnt than petrol creating less pollution.
Gas is also used to fire smaller tri-generation power stations. Gas produces about half the pollution of coal-fired plants. Those who own and invest in gas companies claim that gas is an excellent bridging technology from coal to clean energy. Some environmentalists say we should go all the way to clean energy now and not get stuck on gas at all.
The gas debate in Australia has become very tricky with the explosion Coal Seam Gas (CSG). There is some gas stored in coal seams underground. It has always been too hard to extract until mining companies came up with a way to frack the coal and release the gas.
How is gas ‘fracked’ out of coal seams? They do it by injecting a high pressure mixture of water, salt, sand and chemicals into the coal seams and force the gas out.
Many farmers are concerned about ‘fracking’ as a new way to mine gas. They are worried chemicals will escape into the ground water and contaminate parts of The Great Artesian Basin. This underground network of freshwater lakes provides water for many farmers in QLD and NSW.
Mining companies are allowed to drill on private land because they hold ‘exploration rights’. It turns out that just about the entire country is covered by miners ‘exploration rights.’ Ordinary Australians are getting pretty grumpy about this. This given birth to some unusual alliances: farmers and green groups have united to halt fracking in NSW and have succeeded in some areas. The National Party and The Greens have united to halt fracking and federal Labor and miners are currently united in supporting fracking.
Every day we burn gas equivalent of 55 million barrels of oil.
This is all going to get very tricky in the future: gas supply is expected to peak in 2030 and to be in short supply by the end of the century. Gas is not renewable and like all fossil fuels will pollute our atmosphere when burned until supply runs out.
Gas may be used as a ‘bridging technology’ from coal to clean energy for now. It creates 30% – 20% less pollution when burned than coal but it’s still not clean energy.