1. David E. Bloom Department of Global Health and Population Harvard School of Public Health Global Scenario 2: Demography and Health

3. World population milestones World population in billions Population and year Time taken to add a billion 1 billion in 1804 About 1,000,000 years 2 billion in 1927 123 years 3 billion in 1960 33 years 4 billion in 1974 14 years 5 billion in 1987 13 years 6 billion in 1999 12 years 7 billion in 2012 13 years 8 billion in 2025 13 years 9 billion in 2045 20 years

7. Future demographic and population health indicators and their implications

9. Key Trend #1a Sharp rise in population size UN World Population Prospects, 2006 Revision

10. Key Trend #1b Population growth, but at a declining rate UN World Population Prospects, 2006 Revision

11. Key trend #2 Declining fertility UN World Population Prospects, 2006 Revision

12. Key trend #3 Increasing longevity UN World Population Prospects, 2006 Revision

13. Key trend #4 Modest migration: poor to rich countries UN World Population Prospects, 2006 Revision Countries averaging >100,000 migrants/yr, 2000-2005 (figures are in thousands) Top sending countries (accounting for 59% of all emigrants) Top receiving countries (accounting for 72% of all immigrants)

15. Key trend #5a Changes in median age of population UN World Population Prospects, 2006 Revision

16. Key trend #5b Trends in working-age population share UN World Population Prospects, 2006 Revision

17. Key trend #5c Population aging in China and India UN World Population Prospects, 2006 Revision

18. Key trend #5d Abundance of adolescents and young adults UN World Population Prospects, 2006 Revision

19. Key Trend #6a We’re at the urban “tipping point”

20. Urbanization: Boon or Bane?

21. Key Trend #6b Megacities and beyond…. Tokyo Mexico City New York Sao Paulo