Treehugger Tuesday

World Trash Production Will Likely Triple in 86 Years

Ars Technica just published a sobering article about the world population's ability to create garbage:

Global waste production to triple by 2100, led by sub-Saharan Africa
But if we reduce, recycle, and urbanize, things might not be so bad.
by Jeremy Jacquot - Nov 1 2013, 2:00pm EDT

One of the unfortunate but inescapable consequences of population and economic growth has been the unabated proliferation of trash. The "Great Pacific Garbage Patch" has become as emblematic of our soaring waste output as have the millions of cheap, disposable goods that we've come to rely on.

Every day, we generate over 3.5 million tons of solid waste—a tenfold increase over the past century. That figure will likely double again by 2025. On our current path, it could balloon to over 11 million tons per day by 2100, a tripling of today's rate, with sub-Saharan Africa fueling most of the growth. These worrisome projections, a group of authors argue in this week's Nature, underscore the already obvious need to balance future population growth and urbanization with more stringent waste reduction efforts.

Predicting “peak waste”

The authors based their waste production estimates on a model that blended socio-economic indicators like GDP and education with environmental parameters like energy use and climate trends. They considered 3 scenarios with differing populations and rates of urbanization. The lower the population and higher the urbanization rate, the lower the amount of waste we're expected to generate.

The first scenario, or "Shared Socioeconomic Pathway" (SSP1), represents an idealized future in which fossil fuel dependency and resource intensity are significantly reduced and the 7 billion strong population is 90 percent urbanized. Furthermore, people are more educated and environmentally aware, and poverty levels in developing countries are at an all-time low. In this scenario, waste production peaks at about 8.4 million tons per day by 2075.

SSP2 is the inevitable business-as-usual scenario in which not much has changed from the present day. Some progress has been made in curtailing emissions and income inequality, but the pace of improvement remains slow and uneven. In this scenario, the 9.5 billion population is 80 percent urbanized and produces 11 million tons of waste per day in 2100.

Finally, SSP3 assumes a future in which the world is starkly divided among regions of extreme poverty, moderate wealth and bare subsistence. Little to no progress has been made in addressing pollution and other environmental problems, and global development goals have abjectly failed to come to fruition. Acute poverty and poor education converge to drive the population up to a staggering 13.5 billion, of which only 70 percent is urbanized. Yet, perhaps surprisingly, waste production increases by only 1 million relative to SSP2—to 12 million tons per day.

Unlike SSP1, in which waste output plateaus around 2075, global waste generation shows no sign of slowing, even by 2100, in the latter 2 scenarios. While the model only goes to 2100, it seems likely that there is still room for growth past that in both SSP2 and SSP3.

Leading the way... on waste production

Following these calculations, the authors decided to use SSP2 (business-as-usual) to help them assess how the rate of waste generation would vary by region between the present and 2100. The seven broadly defined regions they considered included sub-Saharan Africa, East Asia and the Pacific, Europe and Central Asia, South Asia, Latin America and the Caribbean, the Middle East and North Africa, and a large group of high-income countries.

While the US and other developed countries still account for a sizable proportion of global waste production, East Asia currently represents the locus of growth. China's output alone, which now exceeds half a million tons per day, could mushroom to around 1.4 million tons per day by 2025. Between 2025 and 2050, South Asia, led by India, is expected to take the lead. After 2050, sub-Saharan Africa surges ahead and, by 2100, is responsible for the production of about 3.2 million tons of waste per day—almost a third of the global total.

One of the authors' central points is that the volume of trash a population puts out stabilizes or even declines as it becomes wealthier and more urbanized (as does the size of the population itself). This is hardly a novel idea, but here it is backed up by the results of their model, which sees waste generation plateau or begin to do so by 2100 in all but South Asia and sub-Saharan Africa.

Reduce, recycle, and urbanize

It's truly a testament to the fact that there are no easy solutions to this global dilemma that most of the remedies that the authors suggest—recycle more, reduce consumption, and be more efficient, among others—have been part of the conversation for decades. They approvingly cite San Francisco, California, and Kawasaki, Japan, both of which have already managed to reduce their waste output by well over half, as examples of what other cities in developed countries should strive for.

But the real challenge lies with developing countries. Improving waste management or urban density is one thing. But it's quite another to discourage consumption in countries like China and India, where rapidly growing middle classes want to consume more. The greatest potential for change could reside in those developing nations, particularly in Africa, that still have relatively low urbanization rates and are plagued by high poverty and inequality. With the right education and incentives, they could be encouraged to embrace sustainability—both as a way of life and as a tool of modernization.

Nature, 2013. DOI: 10.1038/502615a (About DOIs).