Supporters of natural gas as a part of a cleaner energy future usually claim that its production yields half the greenhouse gas emissions of the production of coal.
But new research released by U.S. EPA shows that natural gas production could be 25 percent cleaner than coal or less when methane emissions from the full life cycle of gas production are taken into account.
Original assumptions of greenhouse gas emissions were based only on emissions from tailpipes and smokestacks and not on methane emissions that occur when gas is extracted and transported to power plants via pipes, according to EPA.
Leakage from loose pipe fittings releases the emissions-equivalent of 35 million automobiles a year, said the agency, which uses a program called Natural Gas STAR to track leaked methane emissions. Methane is 21 times more potent as a greenhouse gas than carbon dioxide over a 100-year period, according to EPA.
Based on this information, an average natural gas plant in the United States is 40 percent cleaner than coal and the more inefficient plants are 25 percent cleaner.
Although natural gas still has this advantage over coal, the new research could diminish political arguments for natural gas. The energy source currently has government support, as the Obama administration has painted it as middle ground in the country's search for ways to decrease greenhouse gas emissions.
Duke Energy Corp. CEO Jim Rogers, who has been a proponent of cap and trade, said that the country could end up just being dependent on another fossil fuel by rushing to natural gas.
"What if, with revelations around methane emissions, it turns out to be only a 10 or 20 percent reduction of carbon from coal? If that's true, gas is not the panacea," Rogers said.
Industry groups, though, say natural gas is still more attractive than other options. They point to nuclear, which is still expensive and seen as potentially dangerous (Abrahm Lustgarten, ProPublica, Jan. 25). -- AP