Population Change
Population change is a dynamic process that refers to the fluctuation in the number of individuals in a population over a specific period. This change can arise from various factors, mainly births, deaths, and migration.
The world's population has historically not been stable, with its growth influenced significantly by the number of births and deaths. For considerable periods, particularly up to the 1800s, the population increased very slowly due to high death rates that outpaced birth rates, primarily attributed to poor health facilities and inadequate food supply. In fact, by 1804, the global population reached one billion, and by 1959, it surged to three billion in a phenomenon often referred to as the 'population explosion'. By 1999, this figure doubled once more to six billion, showcasing rapid population growth fueled by declining death rates facilitated by improved health and food security.
Key Points:
- Population Distribution: The distribution of the global population is uneven, with more than 90% residing in approximately 30% of the land area, in crowded regions like South and Southeast Asia and sparsely populated locations such as deserts and high mountains.
- Population Density: Population density measures individuals within a unit area, predominantly expressed as individuals per square kilometer. For instance, India has an average population density of 382 persons per square km.
- Factors Influencing Population Change: Geographical, cultural, social, and economic factors contribute to how populations are distributed across the globe.
- Population Composition: This examines the demographic qualities of the population including age, sex, education, and occupation, often represented visually through population pyramids revealing age-sex distributions.
- Natural Growth Rate: The growth of a population is defined by the difference between the birth rate and the death rate. Migrations also contribute to numerical changes, enhancing the complexity of studying population dynamics.
Understanding population change is vital as it offers insights into societal growth, resource management, and the developmental challenges countries face as they adapt to these shifts.