Fracking has become one the most controversial subjects in the environmental movement. Natural gas is cleaner than coal and oil, but the process used to extract it is raising questions. This article in The Economist takes an optimistic view.
The anti-frackers have reasonable grounds for worry. Producing shale gas uses lots of energy and water, and can cause pollution in several ways. One concern is possible contamination of aquifers by methane, fracking fluids or the radioactive gunk they dislodge. This is not known to have happened; but it probably has, where well-shafts passing through aquifers have been poorly sealed.
Another worry is that fracking fluids regurgitated up well-shafts might percolate into groundwater. A graver fear is that large amounts of methane, a powerful greenhouse-gas, could be emitted during the entire process of exploration and production. Some also fret that fracking might induce earthquakes—especially after it was linked to 50 tiny tremors in northern England last year.
But the risks from shale gas can be managed. Properly concreted well-shafts do not leak; regurgitants can be collected and made safe; preventing gas venting and flaring would limit methane emissions to acceptable levels; and the risk of tremors, which commonly occur as a result of conventional oil-and-gas activities, can be contained by careful monitoring. The IEA estimates that such measures would add 7% to the cost of the average shale-gas well. That is a small price to pay for environmental protection and the health of a promising industry.
For as well as posing environmental risks, a gas boom would bring an important environmental benefit. Burning gas emits half as much carbon dioxide as coal; so where gas substitutes for coal, emissions will fall. America’s emissions have fallen by 450m tonnes in the past five years, more than any other country’s. Ironically, given its far greater effort to tackle climate change, the European Union has seen its emissions rise, partly because of an increase in coal-fired power generation in response to Europe’s high gas price.
If the risks can be managed, this could present an important opportunity. It’s also a huge economic driver now in the United States, so the pressure will be there to find a solution.
