In the 1973 sci-fi classic “Soylent Green,” Charlton Heston’s character faces a dystopian future in which a protein made from plankton is grown in test tubes to sustain an overpopulated Earth.

A new National Academies of Sciences study from 18 top scientists suggests that a similar cultured protein will be needed in the not-too-distant future to deal with the problems of population growth and climate change.