If every couple had exactly two children and maintained that reproductive rate consistently across generations, the human population would eventually stabilize rather than go extinct. This concept is known as "replacement-level fertility," where each couple replaces themselves with two offspring, which means the population remains stable over time.
Here's how it works:
Replacement-Level Fertility: When each couple has two children, they replace themselves in the population. For example, two parents have two children (replacing themselves), and those two children grow up to have two children each (replacing themselves), and so on.
Population Stabilization: Over time, the number of births would equal the number of deaths, resulting in a stable population size. The population growth rate would approach zero, leading to a relatively constant number of people in the world.
It's important to note that this theoretical scenario assumes a constant fertility rate of exactly two children per couple, and it does not account for external factors that can affect population dynamics, such as disease, natural disasters, migration, or changes in social, economic, or cultural factors.
In reality, human population growth has been influenced by various factors throughout history, leading to periods of rapid growth and fluctuations. Currently, the global population is still increasing, but the rate of growth has been slowing down in many regions due to factors like improved education, access to family planning, and economic development.
Sustainable population growth is a significant concern, and many countries are striving to find a balance between maintaining population stability and ensuring the well-being and quality of life for their citizens and future generations.