The planet will be far more populated than previously estimated, so says a new analysis led by the United Nations. We reached the 7 billion mark just three years ago; another 4 billion people will join our ranks by the century’s end.
“The consensus over the past 20 years or so was that world population would go up to nine billion and level off or probably decline,” said co-author Adrian Raftery, professor of statistics and of sociology at the University of Washington, adding, “We found there’s a 70 percent probability the world population will not stabilize this century.”
The new study, published in the US journal Science Magazine and based on the most recent UN population data released in July, estimates that world population will reach 11 billion people by the end of this century. That uptick is largely due to high birth rates in Africa.
Earlier estimates relied upon expert opinions about future life expectancy and fertility rates; the new analysis used Bayesian statistics to generate more accurate predictions. (Bayes theorem is a mathematical method of determining probability. It often produces results that are in stark contrast to our intuitive understanding.)
“This work provides a more statistically driven assessment that allows us to quantify predictions and offer a confidence interval that could be useful in planning,” said UN demographer Patrick Gerland.
The bulk of the boom will occur in Africa, where population is expected to rise from one billion today to four billion by the end of this century. Previous metrics assumed that African birth rates – the world’s highest – would steadily decline with improved access to contraception and women’s education. Instead, birth rates in most African countries have stagnated, likely due to unmet targets in social welfare programs. Wider access to birth control and education for girls and women have been proven to cause a decline in population.
While Africa expands, other populations will likely peak or decline. North America, Latin America, the Caribbean and Europe are all expected to remain stable at under one billion each. Asia is likely to grow from 4.4 billion today around 5 billion people in 2050 and then start to decline.
“Population, which had sort of fallen off the world’s agenda, remains a very important issue,” said Raftery. Overpopulation is a root cause of the planet’s most critical environmental and social problems. More people on Earth will likely exacerbate climate change, infectious diseases and poverty and negatively impact the health and survival of other species. Overcrowding incites social conflict, and places unsustainable demand on all our resources.
Bear in mind, the numbers are projections. John Bongaarts, vice president of the Population Council in New York City said, “It could very well be that we could have epidemics, or wars, or unrest that creates massive mortality. But to be honest, it would require something of a huge magnitude to alter this trajectory.”
Syria’s civil war has caused over 200,000 deaths. In the first half of 2014, IS terrorists murdered an estimated 5,500 Iraqis. The recent Israel-Gaza conflict killed over 2,200. It’s impossible to quantify fatalities linked to record-breaking regional drought. There has to be a better way to stem population growth.
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