In nature, the waste of one system is food for another. Before humans began creating complex materials that nature can't digest, there was no waste, and humans fit nicely into the ecosystem. In the past 100 years, however, humans developed a range of complex materials that nature can't digest. The common solution for most of these materials at the completion of their frequently short lives is putting them in a pile (i.e. landfills) or burning them (i.e. incineration). Both solutions are highly problematic, wasteful and unsustainable.
Landfills, principally used in the Americas, are the worst solution as the materials take years, potentially centuries, to decompose, leaching toxins into the ground and methane into the air. Older (and still common) incineration systems capture some energy, but are not efficient -- and they pollute. Newer systems are much more efficient and clean, but it's still a linear system that promotes a reliance on fossil fuels and presumes materials will always become obsolete.
Some hope has been put in store in the "waste to energy" system, which is a way of capturing energy from the petroleum in waste materials. However, the energy that was put into making the original materials -- and the frequently significant amounts of water and chemicals used when making those materials -- is not captured. When a replacement plastic is made, new production energy, water and chemicals are used, and the wasteful cycle repeats itself. Not only is it an inefficient way to obtain energy, it perpetuates a cycle of relying on fossil fuels for energy.
Compare this linear approach to recycling, when the materials are collected and melted down for reuse as a material. Not only do the original manufactured materials remain in materials form, but the energy and water required to make a replacement product is avoided.
The philosophy of the circular economy is core to solving the human waste challenge. And this is no small challenge. A new World Bank study projects a 70 percent global increase in urban waste, with developing countries facing the greatest challenges. The projected rise in the amount of waste -- from 1.3 billion tons per year today to 2.2 billion tons per year by 2025 -- is projected to raise the annual global costs from $205 billion to $375 billion.
Unfortunately, much of the world, including major economies in Europe, consider "waste to energy" a form of recycling. It's not. Extended Producer Responsibility (EPR) laws, which require that manufacturers contribute to a system that recycles waste resulting from their products and packaging, frequently cover the costs of true recycling only for materials that are easily recycled (paper, glass, aluminum and certain types of plastic). The rest of the waste, much of which could be recycled, is incinerated.
Canada is introducing an ambitious EPR program in 2014, one that may serve as a model for the United States, the world's largest economy and contributor to waste. There are many forces in Canada -- driven by companies that profit from incineration -- lobbying to have WTE included as a form of recycling.
The concept of the circular economy is not a theoretical nicety. It's an urgent agenda for our planet, and one that is at the core of debates about how billions of dollars and countless tons of waste are treated. If recycling were to get to true scale, the economics would improve. The true and often hidden costs of perpetuating a linear economy are significant.
The choice between a healthy nature that has served life on this planet for thousands of years and the Great Pacific Garbage Patch -- a plastic graveyard the size of Texas floating in the Pacific Ocean -- is stark.
This post is part of a series produced by The Huffington Post and The World Economic Forum to mark the Forum's Annual Meeting 2014 (in Davos-Klosters, Switzerland, Jan. 22-25). Members of theSchwab Foundation for Social Entrepreneurship represent a select community of social entrepreneurs who are engaged in shaping global, regional and industry agendas in ways that improve the state of the world. Read all the posts in the series here.