Under the high-fertility projection (in which fertility rates descend from todays levels, but not as rapidly as in other projections), the worlds youth population would exceed 3.5 billion by the end of the century. The need for social resilience is likely to grow, and today’s young will need in their own adulthood to be the main agents of tomorrow’s resilience. Their resilience depends in part on whether they are healthy and educated, whether they have options and opportunities in life, and whether they are fully engaged citizens whose rights are upheld. If girls and young women continue to face gender discrimination, early marriage and barriers to sexual and reproductive health and rights, resilience to rapid social and environmental change will be further undermined.