Limiting Humanity’s Ecological Footprint

Limit humanity’s ‘throughput’ — the energy and resources used in our planetary home and the resulting wastes flowing out — to decrease our ecological footprint.

| May 19, 2014

Limiting throughput and our ecological footprint

The ecological footprint is a useful tool for understanding the flow of materials and energy though an economy.

Photo by Fotolia/overcrew

The way we run the global economy is causing long-term environmental, societal and economic damage, and it’s not improving anyone’s life. Rob Dietz and Dan O’Neill urge us to shift focus from the symptoms to the cause in Enough Is Enough (Berrett-Koehler Publishers, 2013). In a world of finite resources, our economic goal should be the wisdom of enough rather than the madness of more. The following excerpt from “Enough Throughput” provides suggestions for limiting throughput and, in turn, our ecological footprint.

You can purchase this book from the MOTHER EARTH NEWS store: Enough Is Enough.

Throughput and the Ecological Footprint 

Whether a mansion in Monaco, an apartment in Argentina, or a cottage in Cambodia, every household has a measurable metabolism. Materials, from trash cans to ceiling fans, from apple pies to French fries, flow into the household from external sources. Each household also obtains supplies of energy, such as electricity, sunshine, and natural gas, from the outside world. Members of the household consume the materials and use the energy to support their lifestyles. And finally, the household completes the metabolic process by expelling wastes to the environment through carbon dioxide emissions, wastewater discharge, and trash disposal. This metabolism, the flow of materials and energy and the emission of wastes, can be called the throughput of the household.

At the household scale, getting a handle on throughput is relatively easy, even without dragging everything into the front yard like the families in Material World. An audit of household throughput requires tracking how much stuff is coming in and how much waste is flowing out (including exports to the self-storage unit). It also requires documenting energy consumption. For the most part, an auditor would need to collect receipts from shopping, extract data from utility bills, and do some arithmetic—a straightforward, although somewhat tedious, task. But what about a really big household like the economy?

The word “economy” actually derives from two Greek words, oikos (household) and nomos (management). Economics is literally the management of the human household. The larger the household, the more difficult it is to analyze, but researchers have devised useful tools for tracking throughput at broad scales. Material flow analysis is one such tool—a systematic way to assess the flow of materials through an economy. Rooted in the law of conservation of matter, material flow analysis uses mass balance equations to track the flow of materials from environmental sources, through consumptive processes in the economy, and back to the environment in waste streams.

Like a household in which the family rents three self-storage units to manage its overflow of stuff, an economy can also have an overactive metabolism. Material flow analysis suggests that the metabolism of the global economy is much higher than it used to be. Humanity now uses eight times more material resources (by weight) than it did a century ago. Researchers have concluded that “if the present metabolic rate is maintained, there will ultimately be constraints for development. These may occur as resource scarcities at the supply side, or as environmental degradation at the disposal side.”

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