Synopsis
When sewers were built in the 19th century, they were regarded as a blessing. Deadly epidemics that wiped out millions of people became a thing of the past in the Western world. However, sewers also abolished the millennia-old tradition of using our excrement as fertilizer, and broke the nutrient cycle of grow-eat-excrete-compost-to grow food again. The modern flush and forget toilet discards our excrement as waste, while agriculture uses more mineral fertilizers to produce food. Mineral fertilizers which require large amounts of fossil fuels to be extracted or are non-renewable and whose global reserves are uncertain and difficult to predict.
