David Waltner-Toews on 10 Ways Poop Can Save the World
If we see human and other animal excrement as part of a dynamic flux of energy, resources and life, it is easy to imagine ways properly managed poop can “save the earth.” This is not a cow-pie in the sky. It is all within reach. Wear gloves. No sh*t. Know sh*t. From fighting global warming to bringing diverse communities together, here are 10 ways poop can make the Earth a better place.
1. Contribute to energy self-sufficiency
If half the livestock manure in the world were used to produce energy, it could replace about 10 percent of current fossil fuels and save countries billions of dollars. This energy—in the form of methane gas—can be produced from manure and other organic materials through a process of decomposition and bacterial fermentation in a relatively simple apparatus called an anaerobic (oxygen-free) biodigester. The methane can then be used as fuel directly, or used to run engines to produce electricity. Furthermore, the slurry from anaerobic digesters used to generate energy can still be used for fertilizer. Since about one percent of the world’s energy consumption goes into fertilizer production, this is a rare win-win-win situation.
2. Prevent deforestation
Globally, more than two billion people depend on wood energy for cooking and/or heating their homes, putting pressure on already vulnerable forest systems. In many localities, energy from manure (extracted in the manner explained above) can replace much of that dependence on wood fuel.
3. Stabilize global warming
Manure is an important source of methane, which has 23 times as strong an impact on global warming as carbon dioxide. Manure-based anaerobic biodigesters create, contain and use methane as fuel to cook, heat homes and run vehicles. In 2010, the US-EPA reported that the few digester systems already in place directly had reduced methane emissions by 51,000 metric tons, which was the equivalent of removing about 235,500 passenger vehicles from the road.
4. Improve our food supply
Manure can be used more directly in integrated farming systems to generate food for fish and cattle (who can transform, for instance, chicken manure into protein).
5. Improve the drinking water supply
Water quality and quantity are becoming critical issues in the 21st century. By diverting manure through energy production and then into fertilizer, we reduce the contamination of water supplies. And, by using less water to flush personal feces into the public domain, we can reduce water use, as well.
6. Improve public health
Tens of millions of domestic animals (including dogs as well as livestock) produce billions of tons of excrement, some of which contains disease-causing bacteria and parasites. These organisms end up in waterways and food supplies, and are major contributors to bacterial foodborne disease, parasitic infestations and childhood mortality. By channeling the poop through digesters and/or composters, we kill most of the pathogenic bacteria and parasites.
7. Improve our understanding of wildlife
Determining the ranges and food preferences of wild and endangered species by tracking and mapping their scats can lead to more intelligent management of habitats necessary to sustain them.
8. Promote community
If we think locally, the effects of using manure as energy can be profound. Waterloo County, Ontario, where I live, is situated in the Grand River watershed. This area is home to some of the world’s leading computer engineers and physics researchers. It is also intensively farmed by horse-using Mennonite farmers. The human and animal manure produced by citizens and farmers in the Grand River valley could be used to fuel some of the best scientific innovations in theoretical physics, now and into future generations. This would be a collective achievement, bringing people from different industries and communities together, rather than pitting us against each other. There are parts of California that would benefit from similar initiatives.
9. Promote democracy and world peace
Every tyrant, inspirational leader, sage, saint and prophet has produced about 55 kg (120 pounds) of excrement per year of life on earth. Everybody produces more or less the same amount of excrement, regardless of religion, ideology, sex, sexual orientation or economic status. If this were acknowledged, quantified and used to produce energy and fertilizer, we could publicly celebrate each person’s contribution to the global economy. Furthermore, a discussion on these matters could introduce a much-needed sense of levity and humility when our current leaders are shooting the sh*t—I mean, of course, seriously debating—at the United Nations and various councils and conferences of world religions.
10. Promote good public policies and debates
A deeper understanding and discussion about excrement as a resource essential for life will improve everyone’s understanding of ecology, stimulate engineers and landscape architects to devise clever ways to reintegrate excrement production into sustainable urban and rural landscapes and, yes, save the earth for another generation to explore, delight in, and wonder about.
David Waltner-Toews is a veterinarian, epidemiologist, scientist, and popular author. He specializes in diseases other animals share with people, international development, and ecosystem approaches to health. He is the author of "The Chickens Fight Back: Pandemic Panics and Deadly Diseases That Jump from Animals to People," "Food, Sex and Salmonella: Why Our Food Is Making Us Sick," and "The Origin of Feces: What Excrement Tells Us About Evolution, Ecology, and a Sustainable Society."