Carbon dioxide has gotten a lot of press as a global warming element. Methane is the next chemical that gets attention. Why? Because methane is so potent as a greenhouse gas.
A reminder: Methane is a “hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as ruminant digestion and manure management associated with domestic livestock. On a molecule-for-molecule basis, methane is a far more active greenhouse gas than carbon dioxide, but also one which is much less abundant in the atmosphere.” (Source)
Methane is natural but can be increased by activities of people. That seems to be where the debate happens: How do we reduce that activity that increases methane in the atmosphere.
Most of methane’s natural emissions come from places like wetlands; about a third of all the methane floating in the modern atmosphere comes from wetlands. (Source)
Gas and oil drilling allows methane to enter the atmosphere. “Recent studies suggest that wells in the U.S. alone are producing about 60 percent more methane than previously estimated by the Environmental Protection Agency. Worldwide, the energy sector contributes about a quarter of the annual methane budget.” (Source)
Then there is the waste stream. “Microbes in landfills and sewage treatment centers chomp through the detritus humans leave behind and in the process pump out tons of methane each year—about 14 percent of the U.S.’s annual footprint.” (Source)
There’s more to learn about methane all the time. For instance, 39 miles off the coast of North Carolina the seafloor appears to have geysers. “The bubbles are methane gas, seeping constantly from the ocean floor off Bodie Island, at a depth of about 1,300 feet.” (Source)
Happily, those methane bubbles do not hit the surface. It does show that methane as a topic of debate has many facets.
Including this one, an onshore example: “In a secluded corner of rural eastern North Carolina, at the end of a long and winding farm lane, a pit of stinking hog manure is doing its bit to save the world from climate change.”
That NPR story, right, is about pig waste that releases a biogas that is mostly methane. There are people who can use that methane to create energy.
Add to this the idea that we really do not know the extent of this potent gas. Nature magazine ran a report that there can be as much as a 60 percent under-reporting or estimate of methane in current government reports.
Add the issue of timing to the debate, too. “Scientists warn that there could be a more sinister factor at work. Natural chemicals in the atmosphere – which help to break down methane – may be changing because of temperature rises, causing it to lose its ability to deal with the gas. Our world could therefore be losing its power to cleanse pollutants because it is heating up, a climate feedback in which warming allows more greenhouse gases to linger in the atmosphere and so trigger even more warming.”
The methane debate as we read this is going to be about how to manage the chemical and when that must be done. Can we prevent methane from its seep into the atmosphere in those activities that are under human control? How can we tap methane for better end results, like making power.