Unconventional natural gas development and human health: thoughts from the United States
Many countries are exploring the feasibility of unconventional gas development (UGD) as a component of their national energy policy. Broadly, UGD refers to natural gas produced from atypical reservoir types, including coal seam gas (CSG) and shale gas, which require extraction techniques different from those used for conventional production. The development of unconventional natural gas has been a game changer for the United States by significantly increasing domestic supply and lowering gas prices. However, there is a downside that must be considered, including potential harms to the environment, human and animal health and the world’s climate.
Australia is not exempt from controversy over UGD. Since the mid 1990s, billions have been spent on CSG wells, liquefied natural gas plants and export facilities, primarily in Queensland, New South Wales and Victoria. Although CSG is a major industry in Australia, a focus on shale gas extraction, predominantly in Western Australia, South Australia and the Northern Territory, is underway to determine whether the geological properties are sufficient to support commercial production. Australia has large shale gas formations similar in size to the Marcellus and Barnett formations in the US.
The geology and extraction processes for CSG and shale gas differ in that coal seams are typically shallower than gas trapped in shale. Hydraulic fracturing is a well-stimulation method whereby highly…