Editor's Note: This article was originally published in October 2013. The show, from which this article was based, was rebroadcast on Dec. 25, 2013.
The world gains a million people every four and a half days and many are raising concerns about overpopulation and its possible ramifications.
Overpopulation is something that has happened to humans gradually, said Alan Weisman, who is the author of the book, "Countdown: Our Last, Best Hope For a Future On Earth," which examines the question.
According to Weisman, the world’s population in 1968 was 3.5 billion people, and the “population explosion” was a term of concern then. Today, there are 7.2 billion people living on the planet.
As part of his research, Weisman traveled to 21 countries and talked with the world’s top thinkers about the issue of population and sustainability to determine just how many people the planet can fit, how much nature we need to preserve for our own survival and how to design an economy that isn't built on growth and yet, still affords prosperity. He also considered how to convince everyone that this must be done, in a world with a great and large diversity of cultures, religions and politics.
“Every culture starts out with some variation on 'Be fruitful and multiply' because they want to build themselves into a dominant force on the landscape that they inhabit in order to keep inhabiting it,” said Weisman.
This mentality is something that Weisman believes must be overcome. As an example, Weisman indicated that Iran once had the highest growth rate on the planet. Fearing a large unemployed and frustrated generation, the Iranian government started a program acceptable to them under the Koran where the ayatollah issued a fatwa that allowed anyone to access everything from condoms to vasectomies, and provided education on family rearing. According to Weisman this helped bring Iran to a replacement rate a year faster than China.
The impacts of overpopulation to the planet are real and of great concern to Weisman, who said he believes people must do something now to contain it.
“The fastest way we can have a positive influence on our environmental impact is to bring down the number of carbon emitters by gradually bringing our population down over the next couple of generations to a really reasonable level so that the world can continue to hold us,” said Weisman.