Last week I watched the 1973 dystopian film thriller "Soylent Green" for the first time in probably 30 years. The film depicts a society in which climate change has put most of the world into a hellish, near perpetual heat wave (at least during the summer), dramatically increased the inequality of wealth (with the fortunate few living in luxury apartments with air-conditioning), and caused a scarcity of food such that most people are reduced to eating what is called "soylent," a processed wafer-like food that supplies essential nutrients (the production of which is monopolized by one huge corporation called the Soylent Corporation).
You don't have to stretch your mind all that much to see that a lot of what is depicted in "Soylent Green" is already coming true. I found one part of the plot particularly prescient in predicting the decline of plankton in the oceans. You see, in the film plankton form the basis for one type of soylent, namely soylent green. (Soylent red and yellow are also available but less desirable.)
Ostensibly a crime drama, the film follows a police detective played by Charlton Heston who is trying to solve the murder of one of the members of the board of directors of the Soylent Corporation. Ultimately, the detective stumbles onto a forbidden secret: The plankton in the oceans are dying thus threatening the worldwide food supply. As the investigation continues, the detective penetrates a production facility for soylent green where he discovers (spoiler alert!) that soylent green is now being made from recycled bodies of the dead, a sort of civilization-wide cannibalism.