Leaky landfills fuel warming
Open landfills are belching out far more methane than the operators report to regulators, a new study shows. That’s a problem because the greenhouse gas is a big driver of climate change, with a warming effect more than 80 times that of carbon dioxide over 20 years. The organic waste in landfills, much of it food scraps, emits the methane when it decomposes without oxygen beneath layers of long-buried detritus. Most sites have pipes or wells that collect the methane so that it can be burnt off or used to generate heat and electricity, but these often leak. While the EPA requires facilities to measure emissions four times a year through ground surveys, the measurements are incomplete because many parts of landfills are too dangerous to walk through. “You can’t manage what you can’t measure,” lead author Daniel H. Cusworth, from the University of Arizona, tells Scientific American. For the study, researchers flew over 250 landfills in airplanes, using infrared technology to detect the methane. At more than half the sites, they found huge methane plumes that may have been leaking for months or years. The average methane release from the sites was at least 1.4 times the amount reported to the EPA, sometimes nearly 3 times as much. Researchers say pinpointing the leaks this way will allow sites to mitigate them.