You can refer to everyone who will be alive in the future as posterity. A photographer recorded the scene on video for posterity. all the people in the future who will be alive after you are dead preserve/record/keep etc sth for posterity
The race that proceeds from a progenitor; offspring to the furthest generation; the aggregate number of persons who are descended from an ancestor of a generation; descendants; contrasted with ancestry; as, the posterity of Abraham
all of the offspring of a given progenitor; "we must secure the benefits of freedom for ourselves and our posterity"
[MW] n 1 : the offspring of one progenitor to the furthest generation; 2 : all future generations