The Intergovernmental Panel on Climate Change (IPCC) reports that methane, which makes up 95 percent of natural gas, is far more potent a greenhouse gas than previously believed, according to an article on CleanTechnica.com.
Concern about methane leaks has spiked since August, when scientists with the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado at Boulder reported an “alarmingly high” level of methane emissions in the Uintah Basin of Utah — 6.2 to 11.7 percent of total production for an area about 1,000 square miles. The Clean Technica article says that leakage rate “would gut the climate benefits of switching from coal to gas” for power generation.
“We’ve known for a long time that methane is a far more potent greenhouse gas than carbon dioxide (CO2), which is released when any hydrocarbon, like natural gas, is burned,” Clean Technica reports. “But the [International Panel on Climate Change’s (IPCC)] latest report, released Monday, reports that methane is 34 times stronger a heat-trapping gas than CO2 over a 100-year time scale.” The IPCC had previously considered methane to be only 25 times stronger a heat-trapping gas than CO2.
By increasing methane’s Global Warming Potential (GWP) factor from 25 to 34, IPCC has rendered obsolete the methane emission statistics reported by the U.S. Environmental Protection Agency (EPA). “Amazingly, the EPA has been using a GWP of 21 for its estimate of how methane compares to carbon dioxide — a figure that is nearly 20 years out of date,” Clean Technica reports. “That means methane is a whopping 60 percent stronger than EPA calculates in its GHG inventory.”
Reporting on the new IPCC report, EnergyWire quoted Hugh MacMillan, Senior Researcher with Food and Water Watch as saying, “The IPCC presents the scientific consensus, so its conclusions are inherently conservative. It’s bizarre that the EPA is just now moving to adopt the GWPs from 2005. Is the agency going to wait until 2025 to use these new GWPs?”
The revised number means [natural gas fracking] is worse for the climate than we thought, and the benefit of replacing coal with fracked gas is lower than we thought, EnergyWire reports.
“The IPCC reports that, over a 20-year time frame, methane has a global warming potential of 86 compared to CO2, up from its previous estimate of 72,” Clean Technica reports. “Given that we are approaching real, irreversible tipping points in the climate system, climate studies should, at the very least, include analyses that use this 20-year time horizon.”
To read the Clean Technica article, click here.