Raccoons are well known for their affinity for garbage (the internet calls them âtrash pandasâ for a reason), but in reality humans stand out as the trashiest animals on Earth. The average American produced 4.9 pounds of trash a day in 2018, according to the Environmental Protection Agency, and globally we produce 4.5 trillion pounds per year.
This waste ends up in the oceans, in our own bodies, in overflowing landfills â where it causes a variety of issues, from toxic chemical leaching to garbage landslides â and itâs accumulating constantly. âWeâre expecting waste to increase by 73 percent by 2050,â says Silpa Kaza, senior urban development specialist at the World Bank in Washington, D.C.
Itâs clear that we canât launch the trash into space and make it the universeâs problem; itâs just too expensive, with one estimate suggesting such an endeavor would cost $33 quadrillion per year. Even with rocket launches getting cheaper over time, humans simply generate too much waste to be feasibly flung into the stars. But with all this trash piling up on Earth, including more than 550 million pounds of hazardous radioactive waste, what exactly can be done about our gargantuan problem?
Renewed Energy
There are several promising waste-to-energy technologies on the horizon that could improve our ability to sustainably manage waste. These techniques fall after âreduce, reuse and recycleâ on the waste management hierarchy, but before disposal steps such as landfilling. Because waste is so heterogenous, we will always need multiple different methods for handling it.
âThereâs never going to be one silver bullet for waste management,â says Taylor Uekert, a postdoctoral researcher at the National Renewable Energy Laboratory in Golden, Colorado. âYouâre always going to need a portfolio of technologies.â
One such technology is photoreforming, a process that uses sunlight to turn plastic waste into organic compounds and hydrogen gas that can then be used as a source of clean energy. This technology even works with contaminated plastic waste. âIt works with stuff that you wouldnât be able to recycle otherwise,â Uekert says. Itâs definitely a better outcome for plastic than ending up in the deepest parts of the ocean or frozen in arctic ice.
Other technologies â such as pyrolysis, liquefaction, and gasification â use thermochemistry to turn waste into energy. âIn pyrolysis we use heat energy in an inert atmosphere ⊠[to turn] solid organic material [into] bio-oil, biochar and gases,â says Sonil Nanda, director of research and development at Titan Clean Energy Projects Corporation in Canada. Liquefaction uses a series of chemical reactions to turn biological material into bio-oil, a green fuel source, while gasification ultimately produces hydrogen gas.
Whatâs preventing us from using these technologies on a wider scale right now? âThe first thing is lack of awareness,â Nanda says. Another issue is âthe cost, these technologies seem to be a little costly.â Regardless, heâs optimistic about these technologies as well as one of his corporationâs own products: biochar.
Biochar is a carbon material produced by pyrolysis and other processes, and its stable structure allows it to hold carbon for a long time. It therefore has great potential for keeping carbon out of the atmosphere, where itâs best known for contributing to climate change as the greenhouse gas carbon dioxide.
âIt has properties almost equivalent to that of coal,â Nanda says. But make no mistake, biochar has no relation to coal, which is a versatile but far dirtier material. Biocharâs myriad uses include an additive to improve soil fertility, a filter for drinking water and perhaps most importantly, a clean biofuel. âThe Intergovernmental Panel on Climate Change is now recognizing biochar as a carbon-negative material,â Nanda says. âBiochar holds a lot of promises for the future.â
Putting Policies in the Hot Seat
All the technology in the world wonât help us address our solid waste problem until we have the infrastructure, policies and regulations in place to sustainably implement them, however. In developing countries, which struggle disproportionately with effective waste management, the solutions depend on context.
âIf you donât have land available you might think about different solutions, if you donât have money you might think about different solutions,â Kaza says. âIt really depends on the local context, what the capacity is, what resources are available. The technical issues are one small piece of it, [but] even if you have infrastructure in place you need to have the policies in place.â
Waste management also intersects with other issues in these countries, such as labor rights. Dangerous labor is often performed at dumps by informal workers known as waste pickers. These workers often have few legal protections, but their rights and well-being can be incorporated into larger waste management policy solutions. âThere are some places where ⊠a group of informal workers may be given the whole collection contract,â Kaza says. âIt really depends.â
Solid waste management is a global issue, intersecting with other challenges such as climate change, environmental health, environmental justice and civil rights. Promising new technologies may soon help us recover more clean energy from our waste, but we canât ignore the systems that generate such massive amounts of waste in the first place.