Our excrement is a natural, renewable and sustainable resource – if only we can overcome our visceral disgust of it

sludge derived from wastewater treatment plants is processed further, then turned into high-grade topsoil and sold to farming communities. The cities of New York and Boston, for example, have operating sludge-to-fertilizer schemes. The problem is that most municipal sludge is often heavily contaminated by copper, mercury, zinc, arsenic, and chromiu

A gram of feces, when incinerated, yields some 1.5 kilocalories of energy.

Consider this: if high-income nations were to consume at the average level of the rest of the world, we would not be overshooting the safe boundary at all. We’d be operating roughly within the planet’s biocapacity, rather than staring down the barrel of an ecological emergency. By contrast, if everyone in the world were to consume at the level of h

return the animals to the farm so their manure could be composted and used on site.

scientist, author, Senior Fellow at the Post-Carbon Institute, and one of the foremost analysts of our energy future, explained it to me: In short, our rate of consumption is overshooting our planet’s sustainable sources of production. According to the Global Footprint Network, humanity is currently using the equivalent of 1.75 Earths to provide th