Unconventional Natural Gas Sources Bring More Environmental Problems
Posted Apr 27 2009 11:41pm
In 2004 and 2005 U.S. natural gas production went into decline as production at new wells could not keep up with depletion at older fields. Prices spiked causing plans for new gas fired power plants to be scrapped. Many observers thought that we had reach peak gas production in the U.S.
In the years since then, production has rebounded as more unconventional sources of gas have been exploited such as coal bed methane, and shale gas. According to the Energy Information Agency, unconventional gas sources have accounted for all of this growth.
But, while these new sources have allowed the supply of natural gas to grow, they have brought new problems of pollution with them. Another potential source of natural gas, methane hydrates, promises an even larger supply--if the technology can be mastered--but brings with it even larger dangers.
Coal bed methane requires pumping water from underground to release the methane. The process results in water high in salinity and sodium that is often dumped into nearby streams, where it can damage soil, crops and wildlife. In states such as Montana, coal bed methane production has caused controversy among farmers and ranchers who have their lands damaged by this water runoff. Shale gas operations have caused even more problems because they require a process of hydraulic fracturing where large quantities of water, sand and chemicals are injected into the shale to break the rock up and release the gas. Serious episodes of water contamination near drilling sites has been documented in Alabama, Colorado, Montana, New Mexico, Ohio, Texas and Wyoming, which has resulted in a conflict between gas companies and government regulators trying to find out what chemicals are being used in the process.
Even graver risks may result from exploiting methane hydrates which are frozen water molecules that trap methane gas molecules. Enormous amounts of gas could potentially be recovered from methane hydrates trapped in reservoirs beneath the sea floor. The danger lies in the potential for the methane to be thawed and released into the atmosphere. Since methane is also a global warming gas, many times more potent than CO2, such an inadvertant release could result in disastrous climate change. One of the largest extinctions in Earth's history came some 50 million years ago when undersea landslides resulted in the release of methane gas, contributing to global warming that lasted tens of thousands of years.
All of these new sources of energy demonstrate another aspect of resource depletion; it's not only about running out of raw materials, its also about shifting to dirtier, harder to get, and more dangerous resources. With energy sources, in particular, it may seem as though we are continuing to meet demand while the hidden costs continually mount. These costs need to be addressed if we are to find a path to a more sustainable economy.