The sustainability of global human society depends on both the total number of people on Earth and the amount of resources each person uses. Thus a sustainable society could either be composed of many people using few resources each or fewer people using many resources each. If you asked a given human which of these worlds she would prefer, the obvious answer would be fewer people, more resources. We want to be able to travel, to keep our homes at comfortable temperatures, and to have enough food and fresh water that we need never go hungry. Beyond a relatively small population necessary for human culture and diversity to flourish, the addition of more people to the planet does not significantly benefit the people already here, and when we begin to reach resource limits a good case could be made that adding more people is harmful to those already here.
I do not want to be overly prescriptive. I believe in allowing people to make their own decisions, and I certainly don’t want to suggest that anyone alive today ought to be dead. I do, however, want to encourage my readers to weigh the added resource burden of children against the joy and connection to the next generation that children bring into our lives. I offer my own story as a possible model.
For most of my childhood, I was effectively raised by four parents, two of whom had no children of their own. This worked out well enough for me – I maintain a strong connection with all four of my “parents”, and all four have a connection to the next generation through me. I liked this system well enough that I would like to carry it forward, participating in raising children as part of a community without necessarily having children of my own. This type of community child-rearing offers both an opportunity to invest more in our children (through one-on-one time from multiple adult mentors), and a way to achieve negative population growth while addressing the human desire to procreate and raise children.