Sagan's deep concern regarding the potential destruction of human civilization in a nuclear holocaust was conveyed in a memorable cinematic sequence in the final episode of Cosmos, called "Who Speaks for Earth?"
A profunda preocupación de Sagan acerca dunha potencial destrución da civilización humana nun holocausto nuclear quedou plasmada nunha memorable secuencia no último episodio da serie Cosmos, titulado Quen fala en nome da Terra?