Americans dumping twice the trash previously estimated

Americans are dumping twice as much garbage as the EPA had estimated, say scientists, which has dramatic consequences for methane, a contributor to climate change.

The United States is producing more solid waste than ever before.  

A new study by researchers from Yale University calculated just how much Americans throw away on a regular basis, and it’s more than twice as much as federal estimates.

Americans discard five pounds of garbage per person per day, the scientists estimated. In all, US landfills accumulated 262 million tons of municipal solid waste in 2012, compared to the Environmental Protection Agency’s estimates of 122 million tons for the same year. In 2013, the total rose to 294 million tons.

So why the discrepancy? Because people underestimate their own trash use, so these researchers went straight to the landfill operators, according to a university press release.

The EPA has traditionally published waste generation and disposal figures using a “materials flow analysis” method, based on information from industry associations, businesses, the US Census, and the Department of Commerce — indirectly indicating how much will be disposed of in landfills.

The Yale researchers use a more direct method based on numbers reported by the operators of more than 1,200 municipal solid waste landfills, as required by the US Greenhouse Gas Reporting Rule. Landfills didn’t have to report their operational data until 2010; the study used four years of available data, through 2013.

Americans aren't recycling as much as they claim, either. The EPA estimated that Americans recycled 35 percent of their waste in 2012, but the researchers calculated a recycling rate closer to 21 percent.

The trash estimates were actually a secondary finding of the study, published Monday in the journal Nature Climate Change, which focused on the methane gas produced by open and closed landfills.

Methane, a greenhouse gas even more potent than carbon dioxide as a driver of climate change, is produced by the breakdown of other hydrocarbons, including those found in fossil fuels and food scraps.

According to EPA, landfills are the US's third largest source of methane emissions, after petroleum/natural gas systems and "enteric fermentation," the EPA's euphemism for the gases produced by cows.

The Obama administration is proposing to cut methane emissions by nearly half over the next decade to curb climate change.

This study suggests that better gas capturing technology would reduce landfill methane emissions, but Drew Shindell, a climate sciences professor at Duke University, offers a simpler solution: composting.

“We could simply not throw organics into the trash,” Dr. Shindell told Scientific American. “Behavioral change by composting our organics could prevent virtually all the methane emissions from landfills without requiring any of the technological fixes and complex regulations.”