Natural Gas: Pros and Cons

Natural gas has been in the news a lot lately, being hailed as the solution to our energy problems on the one hand, and a potential environmental nightmare on the other. Let’s try to sort out the reality behind this old friend with a new face. Before we start, it might be useful to make a distinction between the natural gas that has historically been collected as a byproduct of oil drilling and the more recently promoted source known as shale gas. This has become newsworthy as the result of an enormous deposit of shale gas discovered in the Marcellus field extending across large sections of Pennsylvania, Maryland, and New York.  Shale gas requires a much more aggressive method of collection since it is buried deep in the earth under many layers of shale. The most popular method of collecting shale gas is hydraulic fracturing, or fracking, a relatively new technology, developed by Halliburton, which has become quite controversial. The move into fracking parallels a gradual takeover of the natural gas industry by the big oil companies.

PROS

• Widely used, contributes 21% of the world’s energy production today
• Delivery infrastructure already exists
• End use appliances already widespread
• Used extensively for power generation as well as heat
• Cleanest of all the fossil fuels
• Burns quite efficiently
• Emits 45% less CO2 than coal
• Emits 30% less CO2 than oil
• Abundant supply in the US. DOE estimates 1.8 trillion barrels
• Low levels of criteria pollutants, (e.g. SOx, NOx) or soot when burned
• Can be used as an automotive fuel
• Burns cleaner than gasoline or diesel
• No waste (e.g. ash ) or residue to deal with
• Lighter than air, safer than propane which is heavier than air
• Can be used to makes plastics, chemicals, fertilizers and hydrogen
• Natural gas industry employs 1.2 million people

CONS

• Non-renewable fuel, supply cannot be replaced for millennia
• Emits carbon dioxide when burned
• Contains 80-95% methane, a potent greenhouse gas (GHG)
• Explosive, potentially dangerous
• Concentrated sources require long distance transmission and transportation
• Energy penalties at every stage of production and distribution
• Requires extensive pipelines to transport over land
• Stored and distributed under high pressure
• Requires turbine-generators to produce electricity
• Liquefied form (LNG) used to transport over water, in tanker ships  is potentially very dangerous
• Energy use competes with use for chemicals and fertilizers
• Additionally, there are significant environmental risks associated with “fracking”
  • Water pollution due to runoff of fracking chemicals
  • Companies are not required to disclose the composition of fracking chemicals (another example of lobbying in action).
  • Water can also bring up adsorbed underground toxins including arsenic
  • GHG footprint of shale gas greater than coal over 100 year time frame
  • Fracking has been linked to earthquakes
  • Casing leaks lead to gas in the water—blazing faucets
  • Fracking requires a large amount of water

The relatively even number of pros and cons shows that this is not an easy choice. Given how widespread and available and “less bad” natural gas is from other fossil fuels, plus the number of jobs created, it is hard to ignore the argument that natural gas should serve as a bridge fuel as more sustainable alternatives are built out. We should keep in mind though, that it is a short term measure and invest accordingly. As far as fracking is concerned, considering that there is already lots of gas available right now, there is no reason (other than greed) to be in a hurry to develop shale gas. Instead, we should take whatever time is necessary to develop a safer, more responsible way to access that gas, while investing heavily in more sustainable sources that will ultimately obviate the need for it.

triple pundit