The size of the world’s population has profound implications for demand for food, energy and resources, land use change and greenhouse gas emissions. This study examines why most population projections have underestimated world population growth, and the implications for actions required to achieve sustainable societies. The main determinant of future population is family size choices. Population projections by different research groups embed different assumptions about drivers of fertility decline. The common assumptions that fertility decline is driven by economic betterment, urbanisation or education levels are not well supported in historical evidence. In contrast, voluntary family planning provision and promotion achieved rapid fertility decline, even in poor, rural and illiterate communities. Projections based on education and income as drivers of fertility decline ignore the reverse causation, that lowering fertility through family planning interventions enabled economic advancement and improved women’s education access. In recent decades, support for family planning has waned, and global fertility decline has decelerated as a result. Projections calibrated across the decades of strong family planning support have not acknowledged this change and are consequently underestimating global population growth. Scenarios used to model sustainable futures have used overly optimistic population projections while inferring these outcomes will happen without targeted measures to bring them about. Unless political will is rapidly restored for voluntary family planning programs, the global population will almost certainly exceed 10 billion, rendering sustainable food security and a safe climate unachievable.
  • kbal
    3•17 days ago

    From the abstract:

    Projections based on education and income as drivers of fertility decline ignore the reverse causation, that lowering fertility through family planning interventions enabled economic advancement and improved women’s education access

    Interesting. I’d noticed that the best-known projections were unreasonably optimistic in some ways when you look at them in detail, but this angle is novel to me.

  • @Phytolacca@r.nfEnglish
    2•16 days ago

    voluntary family planning provision and promotion achieved rapid fertility decline, even in poor, rural and illiterate communities.

    I’d assumed that family planning was more quickly adopted in wealthier areas where people had greater expectations that their kids would survive. Interesting to learn that that’s not necessarily true.

  • LesbianLiberty [she/her]English
    -3•17 days ago

    Yeah, a Queensland university would publish microwaved Malthusianism and call it a day. 10 billion people is possible, we just need socialism.

    • @maketotaldestr0i@lemm.eeMEnglish
      2•14 days ago

      10 billion is possible but so is 16 billion if we all eat cardboard and roach pellets. we are already over carrying capacity socialism doesnt prevent people from continuing environmental destruction. A socialist Iphone …ahem… WePhoneTM destroys the environment just as much. we are already ballls deep into a mass extinction, giving the proles more money just accelerates the ability to be rapacious shitbags.