World population

3.8 Water transfer - Case study: China south-north water transfer project

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World population

  1. Past

    1. Until the 1800s, the global population increased slowly to around 1 billion
    2. Since then, it has grown rapidly, at an “exponential” rate
    3. Billion milestones from 2 billion: 1927, 1960, 1974, 1987, 1999 & 2011

  2. Future

    1. There are three models for the projection of future population growth: high, medium and low
    2. All predict initial growth
    3. High continues this growth, with a possible slight increase in growth rate, to 16 billion by 2100
    4. Low predicts overpopulation, with population falling to 6 billion by 2100
    5. Medium compromises between the two, predicting growth at a slowing rate, reaching 10 billion by 2100