Waste Not, Want Not (Part 1): Waste as a Source of Renewable Energy
We are constantly reminded that we need to live sustainably. To minimize our carbon footprint, we need to save water, save electricity, and when it comes to waste, we are repeatedly told to reduce, reuse, and recycle. The reason for this mantra is that the human population is rapidly reaching a point where it is exceeding the carrying capacity of the Earth. Like all animals, humans require certain elements to sustain us: food, water, and shelter, are the basics. But in the modern age, first world human populations have evolved to depend heavily on electricity for cooking, heating, and to power an array of techno gadgets â€“ necessary for work, play, and everything in-between.
First world countries are characterized by citizens who have also developed into a society that conveniently buys food, drinks, toiletries, toys â€“ and all the other products they require â€“ off the shelf, in nicely packaged and securely wrapped cartons or containers. Gone are the days when handmade clothing, jewelry, and toys, free of packaging and other branding/marketing frills, were purchased. The same goes for food. Very few of us buy freshly picked veggies direct from the farmer. Instead, we buy our food neatly packaged and heavily branded, and we pay dearly for this. In fact, we are so far removed from nature, that when we refer to the 'food chain', we are not referring to the chain of organisms that sustain animals on the next level of the food pyramid â€“ with us being somewhere near the top; we now regard the food chain as the large retail chain of food stores where we purchase our groceries, burgers, or other food products to sustain our hunger. When we've had our fill, we simply toss the remaining food, plus the packaging it came in, into the bin, where it will eventually be collected and taken to a landfill site.
When our waste enters the landfill, recyclable materials such as glass, metal, and paper, may be sorted and recycled; with the waste that is unfit for recycling, remaining on the landfill, where it will accumulate over time. Organic waste products (food, animal waste, plant and animal matter) will eventually decompose. When organic matter decomposes in anaerobic conditions (when no oxygen is present) it releases methane gas. This occurs naturally where plant and animal matter decomposes in oxygen-free environments in nature (for example, in mud at the bottom of swamps, wetlands and dams; or in permafrost and ocean methane hydrates). Methane gas is a double-edged sword; it is a powerful greenhouse gas â€“ twenty times more potent than carbon dioxide â€“ that can contribute heavily to global warming. It is also highly flammable, and a valuable source of energy. As the organic waste on landfill sites lies and rots under mounds of other waste, it gives off methane, which not only contributes to global warming, but due to its flammable nature, makes it a safety risk, as explosions can easily occur. To ensure safety and prevent accidents it it imperative that methane levels and emissions are monitored regularly. Yet, the flammable nature of landfill gas essentially renders waste as a source of renewable energy, which if harnessed, can actually be a boon rather than a bane.
This is part 1 of a 2 part series on landfill gas. Read Waste Not Want Not (Part 2): Harnessing Landfill Gas