Full of crap: why our growing waste is some serious shit
Dec 20, 2013 12:34PM |EMAIL|PRINT
David Waltner-Toews was in Australia to talk shit.
And he has a lot of fun doing it. The Canadian author is a veterinarian, epidemiologist and scientist whose 17 books to date include The chickens fight back: Pandemic panics and deadly diseases that jump from animals to people and Food, Sex and Salmonella: Why our food is making us sick.
His latest is The Origin of Faeces: What excrement tells us about evolution, ecology, and a sustainable society (though its title works slightly better with its Canadian spelling of “fecies” — geddit?). One of its chapters, which details how animals use faeces for communication, including about the presence of a potential mate, is titled “Turds of Endearment”.
“This isn’t in Bambi,” he laughed, “but the mother deer will eat the faeces of the newborn fawn so predators can’t smell it. I don’t know why Disney left that out of the film!”
The puns and asides are all ways to help win mainstream attention for a serious issue: what to do with the 14 billion tonnes or so of human and animal excrement produced each year.
“It’s a subject which people are queasy about,” Waltner-Toews said. “We don’t have a language that allows us to talk about it in reasonable, complex way. It’s either really technical, ‘we’re undertaking nutrient management of biosolids’ for agricultural engineers and urban sewage treatment plants or kind of locker room-style ‘snicker snicker’.”
Waltner-Toews will also return to Australia next March to discuss the book as part of the 2014 Adelaide Writers’ Week. And there is much to discuss, as the book’s blurb says:
“The Origin of Feces takes an important subject out of locker-rooms, potty-training manuals, and bio-solids management boardrooms into the fresh air of everyone’s lives … Approaching the subject from a variety of perspectives — evolutionary, ecological, and cultural — [it] shows us how integral excrement is to biodiversity, agriculture, public health, food production and distribution, and global ecosystems. From the primordial ooze to dung beetles, from bug frass, cat scats, and flush toilets to global trade, pandemics, and energy, this is the awesome, troubled, unexpurgated story of feces.”
Early in human culture and particularly in agricultural societies, he says, humans mimicked much animal behaviour when it came to using excrement as a resource. In south-east Asia, cow pats were dried and burnt as fuel, while in the early 1700s, in Tokyo (then called Edo), home owners and building owners sold their excrement to farmers. If there were fewer people living in an apartment, everyone’s rent went up because there would be less waste for the landlord to sell, he says.
But now, with half the planet living in crowded urban centres, “excrement is mostly seen as a threat”, he says. “You want to get it out, flush it away.”
That’s all fine, he says, until we start to consider both the necessary role of excrement in the planet’s ecosystem, and the sheer weight and numbers now involved. As he wrote in one article:
“Each person on the planet (the average one, somewhere between starving children in the Sudan and obese adults in the US) puts out 150 grams of excrement per day. That’s about 55 kilograms in a year …
“In 10,000 BCE there were about a million people on the planet. That’s 55 million kilograms of human excrement scattered around the globe in small piles, slowly feeding the grass and fruit trees. In 1800, there were about a billion people on the planet, so about 55 billion kilograms …
“By 2013, with more than 7 billion people on Earth, the total human output was close to 400 million metric tons (400 billion kilograms) of shit per year. That is about 80 million large bull elephants’ weight of crap!”
The main problem, he says, is that it’s only seen as a problem. If half the livestock manure in the world was used to produce energy, he says, it could replace about 10% of current fossil fuels and save billions of dollars.
“It’s trying to get people to rethink this whole thing of excrement not as a problem but as a way that materials are circulated,” he said. “How can we do that in such a way that we minimise [health] risk and get all the value out, because that’s what sustains life on the planet.”