INTER-RELATIONS BETWEEN POPULATION AND ENVIRONMENT
Trends in Population Growth
The term “Human population” has been defined as “the dynamics of people, their
numbers, distribution (age and sex structure) and the activities undertaken within a
defined environment”. The scientific gathering, compilation and presentation of data on
human populations vis a vis the changing number of births, deaths and diseases is termed
as Demography. It is derived from two Greek words demos, meaning people or
population and graphos, which means to write, measure, draw or describe. Those
involved in this study are called demographers.
The current world population of 7.6 billion is expected to reach 8.6 billion in 2030, 9.8
billion in 2050 and 11.2 billion in 2100, according to a new United Nations report being
launched today. With roughly 83 million people being added to the world’s population
every year, the upward trend in population size is expected to continue, even assuming that
fertility levels will continue to decline.
China (with 1.4 billion inhabitants) and India (1.3 billion inhabitants) remain the two most
populous countries, comprising 19 and 18% of the total global population. In roughly seven
years, or around 2024, the population of India is expected to surpass that of China.
Among the ten largest countries worldwide, Nigeria is growing the most rapidly.
Consequently, the population of Nigeria, currently the world’s 7th largest, is projected to
surpass that of the United States and become the third largest country in the world shortly
Most of the global increase is attributable to a small number of countries. From 2017 to
2050, it is expected that half of the world’s population growth will be concentrated in just
nine countries: India, Nigeria, the Democratic Republic of the Congo, Pakistan, Ethiopia, the
United Republic of Tanzania, the United States of America, Uganda and Indonesia (ordered
by their expected contribution to total growth).
The group of 47 least developed countries (LDCs) continues to have a relatively high level
of fertility, which stood at 4.3 births per woman in 2010-2015. As a result, the population
of these countries has been growing rapidly, at around 2.4 % per year. Although this rate of
increase is expected to slow significantly over the coming decades, the combined
population of the LDCs, roughly one billion in 2017, is projected to increase by 33 %
between 2017 and 2030, and to reach 1.9 billion persons in 2050.
Similarly, Africa continues to experience high rates of population growth. Between 2017
and 2050, the populations of 26 African countries are projected to expand to at least double
their current size.
The concentration of global population growth in the poorest countries presents a
considerable challenge to governments in implementing the 2030 Agenda for Sustainable
Development, which seeks to end poverty and hunger, expand and update health and
education systems, achieve gender equality and women’s empowerment, reduce inequality
and ensure that no one is left behind.
In recent years, fertility has declined in nearly all regions of the world. Even in Africa,
where fertility levels are the highest of any region, total fertility has fallen from 5.1 births
per woman in 2000-2005 to 4.7 in 2010-2015.
Europe has been an exception to this trend in recent years, with total fertility increasing
from 1.4 births per woman in 2000-2005 to 1.6 in 2010-2015.