A sci-fi horror story, set in New York in 2022 when about 20 million citizens, half of New York's population, are out of work. Voluntary death is encouraged by government clinics and people live on a green food called Soylent. An America plunged into a permanent heat wave, where nature has disappeared. Mostly homeless, its inhabitants are fed only by strange plankton-based biscuits distributed by a sprawling company. In 1973, Richard Fleischer's "Soylent Green", starring Charlton Heston, was the first science-fiction film to evoke a climatic and environmental catastrophe for which man is solely responsible. A true ecological plea, the film also marked the beginnings of environmental awareness on the big screen and was followed by many emulators in Hollywood. But what lessons have been learned over the past fifty years? Soylent Green, directed by Richard Fleischer, is a monument of social science fiction. Released in 1973, it is the first science-fiction film that doesn't evoke an exoge