Carbon dioxide. You hear its name and immediately make negative associations: fossil fuels, global warming, and ozone depletion - the list goes on. Carbon dioxide is the primary greenhouse gas emitted as a result of human activities, and in 2012, it accounted for about 82% of all human-produced U.S. greenhouse gas emissions.  Greenhouse gases are an unfortunate side effect of how our society lives: we rely on the combustion of coal, natural gas, and oil for essentials like energy, transportation, and industrial and agricultural processes. Ever since 1984, when scientists first discovered an atmospheric hole over the Antarctic Ocean, it seems as though we have been in a perpetual struggle to mitigate the grave environmental consequences of carbon dioxide. Of course, this is a worthwhile battle, and we have made progress – just look at the growing popularity of hybrid cars and solar panels – but what is worrying is the lack of public awareness for the overlooked yet devastatingly destructive substance known as methane.
When people think of methane, they connect it to flatulence or science class experiments with fire. This is a problem, because globally over 60% of total methane emissions come from human activities, so as stewards of this planet, need to know how methane is damaging Earth’s environment.
Methane (CH4) is the second most common greenhouse gas generated by human activities in the U.S., and although its lifespan in the atmosphere is much shorter than CO2, it is a far more effective heat absorbent. The Intergovernmental Panel on Climate Change reported in 2013 that it had been underestimating the global warming potential of methane. It found that methane’s impact on climate change is 34 times greater than that of carbon dioxide over a 100 year period – a startling increase from the its previous estimate of 25.
And yet, the implications of methane use continue to become clearer. Recently, fracking has been the trending and purportedly eco-friendly alternative to coal, but natural gas is mostly composed of methane. Studies have found methane leakage at high-producing fracking sites, and that’s not to mention the countless leaks that occur along the methane’s long journey from fracking wells to the 65 million American households dependent upon natural gas. In 2012, a Boston University professor created the first comprehensive city map of methane leaks after discovering 3,356 leaks in Boston. These discoveries are a glaring reminder that more studies need to be done as we decide how to fuel our future.
Leakage is just one of many ways that methane can be released into the atmosphere. In the United States, the majority of methane emissions can be traced back to the oil and gas industry. Globally, the primary source of methane is the agricultural sector, as the gas is a byproduct of the digestive process of domestic livestock and our management of the resulting manure.
The energy and agricultural industries are so big that it’s difficult to imagine how one person can take on these institutions to try and enact lower methane emissions, but there are ways that the individual can take action. Landfills are the third largest source of methane emissions in the U.S., and landfill size is increasing. This is where you can make an impact by reducing the amount of organic waste you produce (i.e., food waste, paper products, yard trimmings, and wood waste). Almost 50% of all organic waste ends up in landfills, but this doesn’t have to be the case! Organic waste is the main source of methane coming from landfills, but since it is biodegradable, most of it can be recycled in some way. At the very least, you can make a conscious effort to always recycle your papers, bottles, and cans, and to minimize food waste.
The good news is that there is action being taken at the government level. As part of President Obama’s Climate Action Plan, the Environmental Protection Agency (EPA) is updating its emissions standards for new and existing landfills. Furthermore, the EPA is considering either requiring mandatory compliance or issuing recommended guidance for methane emissions control. Obviously, mandatory compliance would be the more effective (albeit more costly) action compared to guidance. We will have to wait and see what kinds of forward-looking policies the EPA will ultimately propose come January 2015.
At the state level, it is encouraging to see that San Francisco, since making food-waste composting mandatory in 2009, has reached 80% waste diversion, and Maryland has announced a goal of sending zero waste to landfills by 2040. Nevertheless, the public should be more cognizant of this other greenhouse gas, and both type of emissions – carbon dioxide and methane – should be addressed if the world is to effectively counter climate change.
 “Carbon Dioxide Emissions.” Overview of Greenhouse Gases. United States Environmental Protection Agency. July 2014. http://www.epa.gov/climatechange/ghgemissions/gases/co2.html
 Joe Romm. “More Bad News for Fracking: IPCC Warns Methane Traps Much More Heat Than We Thought.” Climate Progress. October 2, 2013. http://thinkprogress.org/climate/2013/10/02/2708911/fracking-ipcc-methane/
 Joanna Foster. “Methane is Popping Up All Over Boston.” The New York Times. November 20, 2012. http://green.blogs.nytimes.com/2012/11/20/methane-is-popping-up-all-over-boston/
 “Methane Emissions.”
Overview of Greenhouse Gases. United States Environmental Protection Agency. July 2014. http://epa.gov/climatechange/ghgemissions/gases/ch4.html
 Danielle Baussan and Erin Auel. “The Treasure of Diverted Trash.” Center for American Progress. September 7, 2014. http://www.americanprogress.org/issues/green/news/2014/09/17/97292/the-treasure-of-diverted-trash/
 Danielle Baussan and Erin Auel. “The Treasure of Diverted Trash.”