The rapid aging of populations around the world presents an unprecedented set of challenges: shifting disease burden, increased expenditure on health and long-term care, labor-force shortages, dissaving, and potential problems with old-age income security. We view longer life spans, particularly longer healthy life spans, as an enormous gain for human welfare. The challenges come from the fact that our current institutional and social arrangements are unsuited for aging populations and shifting demographics; our proposed solution is therefore to change our institutions and social arrangements. The first section of this essay provides a statistical overview of global population aging and its contributing factors. The second section outlines some of the major challenges associated with widespread population aging. Finally, the third section of the essay describes various responses to these challenges, both current and prospective, facing individuals, businesses, institutions, and governments.