Switching from coal to gas can increase global warming – NCAR

[UPDATE JAN 20 2012: New study published in journal Climatic Change shows large volumes of methane released during fracking]

By Stephen Leahy 

DURBAN, South Africa, Dec 5, 2011 (Tierramérica)

Hydraulic fracturing or “fracking” is being used to tap the last remaining natural gas deposits across large areas of the United States and western Canada, fueling continued dependence on hydrocarbons instead of a shift to genuinely clean energy sources to cool the planet.

Called shale gas, these deposits represent a new and enormous source of fossil fuel.

“Fracking is driving exploration and drilling all over the United States,” said Gwen Lachelt of the non-governmental organisation Earthworks’ Oil & Gas Accountability Project.

“The oil and gas industry is marching across America from Texas to North Dakota and from the east coast to California,” Lachelt told Tierramérica.

There may be as much as 23,427 billion cubic metres (bcm) in recoverable gas from U.S. shale formations, according to the Annual Energy Outlook 2011, released in April by the U.S. Energy Information Administration (EIA).

The United States will consume 650 bcm of natural gas this year, the EIA projected. Globally, it estimates reserves of “unconventional gas” – the oil and gas industry term for shale gas and coal bed methane – at 915,000 bcm, with 100,000 bcm in Latin America.

However, that estimate is already out of date due to developments in fracking technology and exploration. The EIA estimate of shale gas in the United States in 2009 was less than half the 2011 estimate.

Fracking uses horizontal drilling and hydraulic fracturing with high pressure water and chemicals to fracture gas-bearing shale rock.

Holes are drilled vertically as little as 100 metres and as much as 3,000 metres into the shale, and then horizontally 1,000 metres along the shale formation. Chemicals and large amounts of water are pumped underground at high enough pressure to fracture the shale, releasing the gas into the pipeline.

The “dash for gas” as the industry pundits like to say is being driven by potential exports to Asia and the mistaken belief that natural gas is the “transition fuel” from coal to a low-carbon economy.

It is true that natural gas is “cleaner” in that it releases about 40 to 45 percent less carbon dioxide than coal does to produce the same amount of energy.
However, gas from fracking has a higher carbon footprint because more energy is needed to get the gas and because methane leaks out.

Methane has 25 times the warming impact of carbon dioxide.

Switching from coal to gas as an energy source could result in increased global warming, not less, according to the study “Coal to Gas: The Influence of Methane Leakage”, released in September by the U.S. National Center for Atmospheric Research (NCAR).

This is mainly due to the methane leakage problem, which is common but unregulated.

[UPDATE JAN 20 2012: New study published in journal Climatic Change shows large volumes of methane released during fracking]