Due to immigration, the decline in mortality rates, medical breakthroughs, and increased birth rates, populations will always increase and eventually gives rise to overpopulation.
Falling Mortality Rate
The primary (and perhaps most obvious) cause of population growth is an imbalance between births and deaths.
When demographers attempt to forecast changes in the size of a population, they typically focus on four main factors: fertility rates, mortality rates (life expectancy), the initial age profile of the population (whether it is relatively old or relatively young to begin with) and migration.
The number of humans existing on Earth has never been as high as it is now. In 1800, Earth had approximately 1 billion inhabitants, which rose to 2.3 billion in 1940, then 3.7 billion in 1970, and approximately 7.5 billion today. In the last five decades, Earth has experienced an extreme population boom.
Human population has grown exponentially over the past century. It has done so largely by producing large amounts of food, and learning how to control disease. Ten thousand years ago, when humans first invented agriculture, there were maybe one million humans on the planet.
According to demographers — people who study the growth, density, and other characteristics of the population — there are three major factors that affect population growth. These factors are fertility rate, life expectancy, and net immigration levels.
The Philippines' Commission on Population and Development selected Vinice Mabansag, a baby girl born in Manila, as the symbolic eight billionth person on Earth.
Estimates vary, but we're expected to reach "peak human" around 2070 or 2080, at which point there will be between billion and 10.4 billion people on the planet.
Earth's capacity
Many scientists think Earth has a maximum carrying capacity of 9 billion to 10 billion people.
Larger populations require more food, water, and energy, and consequently tax the earth's ability to replace used resources. Overpopulation depletes wildlife to dangerously low levels. Overfishing has ruined many formerly fertile fishing grounds.
What's behind India's growing population? The biggest factor behind India's massive population is its young people: 650 million Indians—nearly half the country's population—are below the age of 25.
One of the most obvious ways to decrease population is for people to have fewer children. In countries where babies and young children are less likely to survive into adulthood, it is more common for families to have a larger number of children.
In fact, China's population is greater than the entire population of Europe (744 million) or the Americas (1.04 billion) and roughly equivalent to that of all nations in Africa (1.427 billion).
Overpopulation in China began after World War II in 1949, when Chinese families were encouraged to have as many children as possible in hopes of bringing more money to the country, building a better army, and producing more food.
What are the 5 effects of rapid population growth? The 5 effects of rapid population growth are increased economic growth of a country, growing demand for jobs, lack of housing and schools, lack of infrastructure leading to poor living, and increase in pollution and waste.
The study, commissioned by the nonprofit organization The Club of Rome, predicts that if current trends continue, the world's population, which is currently 7.96 billion, will peak at 8.6 billion in the middle of the century before declining by nearly 2 billion before the century's end.
China currently holds the number one spot on this list. But the population of India is expected to surpass that of China's by later this year, eventually reaching a total of 1.67 billion in 2050.
Picture This. In just 30 years, the world will look very different. Since 1950, the global population has grown from 2.5 billion to more than 7.7 billion. By 2050, however, that number is projected to reach just 9.7 billion.
About 385,000 babies are born each day according to the UN. That adds up to more than 140 million a year.
With this context and timeframe in mind, the demographers estimate that 109 billion people have lived and died over the course of 192,000 years. If we add the number of people alive today, we get 117 billion humans that have ever lived.
Have you ever considered how many babies are born every second around the world? There are an estimated 130 million babies born each year around the globe, in the UK, Europe and Central Asia, there are 0.35 babies born every second, which equates to 21 every minute.