America"s natural gas system is leaking methane and in need of a fix

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/SMDScu11ewQ

The first thorough comparison of evidence for natural gas system leaks confirms that organizations including the Environmental Protection Agency (EPA) have underestimated U.S. methane emissions generally, as well as those from the natural gas industry specifically.Natural gas consists predominantly of methane. Even small leaks from the natural gas system are important because methane is a potent greenhouse gas — about 30 times more potent than carbon dioxide. A study, “Methane Leakage from North American Natural Gas Systems,” published in the Feb. 14 issue of the journal Science, synthesizes diverse findings from more than 200 studies ranging in scope from local gas processing plants to total emissions from the United States and Canada.”People who go out and actually measure methane pretty consistently find more emissions than we expect,” said the lead author of the new analysis, Adam Brandt, an assistant professor of energy resources engineering at Stanford University. “Atmospheric tests covering the entire country indicate emissions around 50 percent more than EPA estimates,” said Brandt. “And that’s a moderate estimate.”The standard approach to estimating total methane emissions is to multiply the amount of methane thought to be emitted by a particular kind of source, such as leaks at natural gas processing plants or belching cattle, by the number of that source type in a region or country. The products are then totaled to estimate all emissions. The EPA does not include natural methane sources, like wetlands and geologic seeps.The national natural gas infrastructure has a combination of intentional leaks, often for safety purposes, and unintentional emissions, like faulty valves and cracks in pipelines. In the United States, the emission rates of particular gas industry components — from wells to burner tips — were established by the EPA in the 1990s.Since then, many studies have tested gas industry components to determine whether the EPA’s emission rates are accurate, and a majority of these have found the EPA’s rates too low. …


Read More: America"s natural gas system is leaking methane and in need of a fix

#Agency, #Alzheimer, #Brandt, #California, #Count, #Department, #Energy, #Epa, #People, #Pregnancy, #Science