"Soylent Green" takes place in 2022 in a New York City that has ballooned to hold 40 million residents. The world is polluted, the human population too big, and life in the city is hard. Food mostly takes the form of processed rations sold by the Soylent Corporation — but even that is in short supply. The streets are full of hungry homeless people, and New York City Police Detective Ty Thorn has a murder to solve.
In the course of his investigation, Thorn uncovers the disturbing truth that Soylent Green — the newest brand of food rations produced by the Soylent Corporation — is made from people, not algae as the company claims.
While it is a bit far-fetched to think that we'll ever be eating human-based processed food, we do have a fairly fragile food system that's entirely dependent on cheap energy. What will everyone eat when gas is $20/gallon? What will people eat when a head of lettuce costs $100, an apple $50?