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Supplementary Materials

Erratum: several readers have pointed out to me an error on page 36 of the printed book. I said: “The waste that plants excrete (through the leaves) is mostly oxygen (at night) and carbon dioxide (by day).” My bad! This is incorrect. Plants combine carbon dioxide + water + light and produce sugars and oxygen. This is called photosynthesis. Obviously this only happens when there is light – sunlight in daytime, or under special lights. To grow, plants take the sugars & oxygen and produce energy (for growth etc) and carbon dioxide. This is called respiration, and happens 24 hrs a day.

The Ecology of Gut and Environmental Microbiomes are the frontier of ecology and medicine in the 21st century. See



Researchers culture new evolutionary branch of bacteria from human bowels and the environment.

Page 145 of Nature Volume 502, dated 10 October 2013, has the following bit of exciting news:
New bacteria from the bowels
A new evolutionary branch of bacteria has been discovered in human guts and in groundwater.
While characterizing microbial communities in human faeces and environmental samples, a team led by Jillian Banfield at the University of California, Berkeley, and Ruth Ley at Cornell University, Ithaca, New York, found DNA sequences that were distantly related to photosynthetic cyanobacteria.  Further sequencing produced three complete and three partial genomes for the bacteria.  The authors assigned the microbes their own phylum — Melainabacteria. 
The Melainabacteria lack genes required for photosynthesis and for coping with oxygen.  They probably generate energy by fermenting various carbon-containing molecules, and may provide their human hosts with the vitamins B and K.

The Importance of Wild Animal Poop: Big Animal Extinction Impoverishes Soil

What a waste: Turning poo into plastic – see more here

Been There, Dung That: 10 ways excrement can save the world


Reprinting an article by David Waltner-Toews that first appeared in, Indian Country notes that: “These concepts are not new in Indian country. Witness the technical assistance grant earlier this year bestowed by the U.S. Department of Energy on the Ho-Chunk Nation of Black River Falls, Wisconsin, to develop a one- to two-megawatt biomass waste-to-energy plant. “The plant could potentially use municipal solid waste, agriculture waste or other biomass resources to offset tribal facility energy costs,” the DOE said in a press release in May. ”



Herbicide Passes Through Cow – Cow fine, Manure bad

First Use of Manure as Fertilizer in Europe dates back 8000 years: “subsistence farmers are extremely observant” – of course they are!

Why Marie Myung-ok Lee Donated her Poo

Earthworm poo can be used to measure past temperatures, providing a window into the ancient climate.

See the story here on the BBC Science site


An ingenious use for frass (insect feces) – Anthony can Dyck introduces us to “Bug-Shit Tea” Chinese tea!



Some people have requested more details of how I calculated the amount of excrement in the world.

For a table of how I did the calculations, have a look at this. You can download the table here.



There are many companies that are taking integrated and enlightened approaches to dealing with excrement. A couple of which I am aware in my own region (Waterloo) are below. I will add to the list as I become aware of more.

  • Lystek, a Canadian company based in Waterloo, Ontario, sees excrement and other organic wastes as resources. Click here to read more.
  • Enermodal Engineering describes itself as “Canada’s largest consulting firm exclusively dedicated to creating green buildings and communities”. Click here to read more.

Dog Shit Goes Global

In the book, I talk about Matthew Mazzotta’sPark Spark in Cambridge, MA, using dog poop to power a park lamp. His idea is now inspiring others. See more here.

Indiana Dairy Farm uses Manure to Fuel its Trucks

Connecticut Company Turns Horse Manure into Fuel

Biogas for the home:


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