Methane emissions from natural gas production and distribution may be much worse than thought, according to a recent article in the New York Times.
The article quotes Touche Howard, the inventor of methane detection technology, as saying that the devices used worldwide to measure natural gas methane emissions may be inaccurate. Natural gas is 95 percent methane, which is a greenhouse gas with 84 times the potency of carbon dioxide over a 20-year time frame.
Howard wrote in a peer-reviewed science journal that methane leakage calculations "could be affected by this measurement failure" and that a recent study conduct by the University of Texas and by sponsored by the Environmental Defense Fund "appears to have systematically underestimated emissions."
"If the supposed flaws are borne out, the finding could also have implications for all segments of the natural gas supply chain, with ripple effects on predictions of the rate of climate change, and for efforts and policies meant to combat it," The Times wrote.
Howard's paper describes a pattern of low measurements of leaks by the Bacharach Hi Flow Sampler, a device approved by the Environmental Protection Agency for its required monitoring of natural gas facilities and in use around the world, the article states.
Howard reports that he backpack-size methane measurement tool uses two sensors: one for low levels of methane emissions and one for higher levels. As methane levels rise beyond the capacity of the first sensor, the device hands off to the second, high-level sensor, The Times wrote. Howard found that under some conditions, unless the sampler is carefully and frequently recalibrated, the switchover from the first sampler to the second can fail. When that occurs, the device does not measure the amount of methane that the second sensor would capture, and so it under-records methane leakage rates.
Howard, a semiretired gas industry consultant and firefighter who lives in North Carolina, holds the patent for a high-flow-rate sampler whose technology is used in the Bacharach product.
When the device malfunctions, there is no way to determine the magnitude of the error, so the missed emissions could be extremely high -- perhaps tenfold to a hundredfold for a particularly large leak, The Times wrote in reporting on Howard's article.
To read the New York Times article, click here.