World Population Poised to Hit 7 Billion.

BY: LARISA EPATKO

On Monday, a baby will be born somewhere and demographers will proclaim that the world's population has reached 7 billion. That's good news and bad news, according to a United Nations Population Fund report released Wednesday.

People are living longer and leading healthier lives. But there are plenty of worries that the globe may not have enough food and water to sustain rapidly growing populations.

The date itself, Monday, is a symbolic one, extrapolated from census data, surveys and population registers, but the implications are real, the United Nations says. (Read the U.N. Population Fund's full report.)

Even though fertility rates are lower than in the past, the population is still expected to rise naturally through what is known as population momentum, said Richard Kollodge, editor of the U.N. report.

Each incremental growth of a billion takes less and less time. Those increases are attributable to positive factors, said Kollodge. "People are healthier; they're living longer. Child mortality is down. This relatively recent surge in population growth for the most part can be seen as good news."

View past and projected global population growth:

In South Asia and Africa, population growth is most prolific. Many countries in sub-Saharan Africa have high population growth rates and high fertility rates but low economic growth rates, which can be problematic, said Kollodge. "The population is growing faster than the government's ability to meet the need for services, education and health. Economic growth isn't keeping up with population growth," so the countries become poorer.

In the middle-income countries -- mainly in Latin America -- population growth has stabilized, he said. But they still face challenges of rapid urbanization and people moving in and out of the countries quickly, which governments are trying to manage.

Asia's population, currently at 4.2 billion, is expected to remain the highest during the 21st century, according to the Population Division of the United Nations Department of Economic and Social Affairs. Photo of Dotombori, the entertainment district of Osaka, Japan, by photholic.com via Flickr Creative Commons.

But even while the world's population is growing, in some wealthy industrialized countries -- including several European nations and Japan -- populations are shrinking because fertility rates are not high enough to replace population losses. That means there aren't enough young people entering the work force to sustain economic growth and pension systems are receiving less funding to support the elderly, said Kollodge.

"They're also dealing with issues of migration and asking questions of, 'If our populations are shrinking, should we invite more people from other countries to come in and meet labor shortages?'" he said.

The U.N. report makes some recommendations for addressing population challenges, such as giving women access to reproductive health services, education and good jobs. "When women are educated and healthy, they choose to have smaller families, and when they do have smaller families, their children end up being healthier," said Kollodge.

Africa's population is expected to more than triple, from 1 billion in 2011 to 3.6 billion in 2100, according to the United Nations. Photo by Novartis AG via Flickr Creative Commons.

The report also recommends investing in youth. About 1.8 billion young people, between the ages of 10 and 24, live around the world now, he said. "That's the largest youth cohort in human history. So we're advocating for making sure that all these young people have education, that they're all in good health and free of HIV, that they have opportunities, that they are empowered to drive our future economies."

But all of that takes money. Sexual reproductive health initiatives alone -- an action plan was proposed at a 1994 population summit of 179 countries -- would cost $68 billion in 2011. Countries agreed to pay $34 billion and international donors $10.8 billion, but that left a nearly $25 billion gap, Kollodge said.

The elderly also are a growing segment of the population, raising the challenge of who will take care of them and how social security programs will be funded. "But also look at the flip side -- let's not create a world where the elderly are only dependent," but are active and independent and continuing to contribute to their communities, he said.

"Those are big challenges and it's better to plan for them now because the world is only going to grow older in the years ahead," he said.

And depending on fertility rates, the next milestone birthday -- when the world hits 8 billion people -- might be as soon as 2025.