Last fall, the world marked a major milestone: According to the United Nations (UN), the number of people on Earth reached 7 billion and couting
A crowded planet
It took from the dawn of humankind, some 50,000 years ago, until 1804 for the population to reach a billion.In 123 years it gained another billion – and yet another billion just 32 years later.Some people alive today have seen the population triple in their lifetimes!
A crowded planet
The world's population reached 1 billion in 1800 and 2 billion in 1925 according to UN data reported in the journal Science. The world's population has grown spectacularly since the industrial periods of the mid-18th century.
A crowded planet
By 2050, the population will hit 9.3 billion, and 97 percent of the growth will come from less developed regions said David Bloom, the author of the study and economist at Harvard University.
A crowded planet
However, the growth rate is expected to slow down by the year 2100 as the countries with the highest birth rates develop better female education and family-planning systems.
A crowded planet
What caused the population explosion? Medical advances like vaccines, along with better nutrition, and sanitation have helped more children survive to adulthood.People are also living longer than ever before.
A crowded planet
If there are more births than deaths, the population grows,” says Gerhard Heiling, who compiles demographic information, or statistics about the characteristics of populations, for the UN.
A crowded planet
More people means strain on the environment.Luckily, human population growth has slowed in the past 50 years.”People, on average, are having fewer children than in the past” says Heilig
A crowded planet
As humanity grows, so do the challenges it faces.Many people still lack basic necessities, such as clean water and food.There also aren’t enough jobs or schools for everyone.Tackling these problems is important for everyones future as Earth becomes increasingly cramped.
A crowded planet
Worldwide fertility rates have fallen to the current global average of 2.6 children per woman.Areas with higher fertility rates have a growing, younger population, while araeas with lower fertility rates are experiencing a shrinking, aging population.