World Population: 7 Billion

On October 31, 2011, the United Nations is expected to announce a projected world population figure of 7 billion. This global milestone presents both an opportunity and a challenge for the planet. While more people are living longer and healthier lives, says the U.N., gaps between rich and poor are widening and more people than ever are vulnerable to food insecurity and water shortages. Because censuses are infrequent and incomplete, no one knows the precise date that we will hit the 7 billion mark - the Census Bureau puts it somewhere next March. In the last 50 years, humanity has more than doubled. What could the next decade mean for our numbers and the planet? In this post, we focus on births, but we'll be back with population-related content including it's affect on the environment and our food supply. -- Paula Nelson (47 photos total)

A baby, minutes after he was born inside the pediatric unit at hospital Escuela in Tegucigalpa, Oct. 21, 2011. According to Honduras' health authorities, about 220,000 babies are born in Honduras each year. The cost of having a baby delivered at the public hospital is $10. (Edgard Garrido/Reuters)

A Cuban doctor inspects patient Amareli Suarez, 22, who is 36 weeks pregnant, at a public maternity hospital in Gatire on the outskirts of Caracas, Oct. 5, 2011. The hospital is part of the 'Barrio Adentro' program, which is a collaboration between the governments of Venezuela and Cuba, where highly trained Cuban doctors help provide publicly-funded health care for poor and alized communities in Venezuela. (Jorge Silva/Reuters)

A Cuban doctor covers the eyes of a premature baby in the natal intensive care unit of a public maternity hospital in Gatire on the outskirts of Caracas, Oct. 5, 2011. (Jorge Silva/Reuters)

Cuban doctors attend a birth as Venezuelan students watch at a public maternity hospital in Gatire, Oct. 5, 2011. (Jorge Silva/Reuters)

Obstetrician Ana Lara carries baby Diego Alejandro, born by caesarean in the private Aquamater clinic in Caracas, Sept. 10, 2011. Aquamater opened in 1999 and is the first centre specializing in waterbirths in Venezuela. It aims to advise couples, who pay a fee, on techniques for breastfeeding, pain relief and different ways of giving birth. (Jorge Silva/Reuters)

Cuban neonatologists watch over premature babies in the natal intensive care unit of a public maternity hospital in Gatire, Oct. 5, 2011. The hospital is part of the 'Barrio Adentro' program, which is a collaboration between the governments of Venezuela and Cuba. (Jorge Silva/Reuters)

A premature baby sleeps in an incubator in the natal intensive care unit at a public maternity hospital in Gatire, Oct. 5, 2011. Highly trained Cuban doctors help provide publicly-funded health care for poor and alized communities in Venezuela as part of the 'Barrio Adentro' program (Jorge Silva/Reuters)

Katy, who is 37 weeks pregnant, takes part in a prenatal course in the swimming pool of the private Aquamater clinic in Caracas, Oct. 1, 2011. Aquamater opened in 1999 and is the first centre specializing in waterbirths in Venezuela. (Jorge Silva/Reuters)

Katy and her husband Facundo, practice her breathing during a swimming pool prenatal course run by the private Aquamater clinic in Caracas, Oct. 1, 2011. (Jorge Silva/Reuters)

Pregnant couple Kerwin and Astrid, both 19 years-old, attend a prenatal course given by the private Aquamater clinic in Caracas, Oct. 1, 2011. (Jorge Silva/Reuters)

Pregnant women exercise during a prenatal course conducted by the civil association Nina Madre (Child Mother) in Caracas, Sept. 21, 2011. (Carlos Garcia Rawlins/Reuters)

Pregnant women wait for their turn to undergo a Cesarean section (c-section) procedure at the Santa Ana public maternity hospital in Caracas, Oct. 19, 2011. (Carlos Garcia Rawlins/Reuters)

Doctors hold one of the newborn triplets of Yojaimi Garcia, 20, as she undergoes a caesarean section at the Santa Ana public maternity hospital in Caracas, Oct. 23, 2011. (Carlos Garcia Rawlins/Reuters)

A newborn baby is measured by a doctor minutes after he was born, inside the childbirth unit of the Santa Ana public maternity hospital in Caracas, Oct. 19, 2011. (Carlos Garcia Rawlins/Reuters)

A nurse fills baby bottles inside the child care unit at the Santa Ana public maternity hospital in Caracas, Oct. 22, 2011. (Carlos Garcia Rawlins/Reuters)

Idaima Lopez, 24, pregnant with triplets, waits in a bed in a public maternity hospital in Gatire, Oct. 5, 2011. (Jorge Silva/Reuters)

A Cuban doctor checks on a pregnant woman at a Barrio Adentro clinic in Naiguate in the state of Vargas, Oct. 6, 2011. The Barrio Adentro' program, which is a collaboration between the governments of Venezuela and Cuba, brings highly trained Cuban doctors to help provide publicly-funded health care for poor and alized communities in Venezuela. (Jorge Silva/Reuters)

A mother and her newborn lay on a bed inside the childbirth unit at hospital Escuela in Tegucigalpa, Oct. 21, 2011. The cost of having a baby delivered at the public hospital is $10. (Edgard Garrido/Reuters)

The bloodstained feet of mothers are seen after they've given birth inside the childbirth unit at hospital Escuela in Tegucigalpa, Oct. 21, 2011. (Edgard Garrido/Reuters)

Mothers wait to be admitted to give birth at hospital Escuela in Tegucigalpa, Oct. 21, 2011. (Edgard Garrido/Reuters)

A premature baby sleeps in an incubator in the natal intensive care unit in a public maternity hospital in Gatire, Oct. 5, 2011. (Jorge Silva/Reuters)

Maria Pena, 19, carries her five day-old baby as Carmen Cartaya holds her four day-old nephew in a public maternity hospital in Gatire, Oct. 5, 2011. (Jorge Silva/Reuters)

Mothers and newborn babies wait on beds inside the childbirth unit at hospital Escuela in Tegucigalpa, Oct. 21, 2011. (Edgard Garrido/Reuters)

A baby's foot is exposed between the sheets at hospital Escuela in Tegucigalpa, Oct. 21, 2011. (Edgard Garrido/Reuters)

Newly born babies rest inside a ward at a hospital on the occasion of "World Population Day" in the northern Indian city Lucknow, July 11, 2009. (Pawan Kumar/Reuters)

A baby stretches its hand from under a quilt at a local hospital in Jiaxing, Zhejiang province, Oct. 25, 2011. (Reuters)

A nurse cares for babies inside the maternity ward of a hospital in Taipei, Oct. 25, 2011. (Pichi Chuang/Reuters)

A nurse looks after a three-day-old baby inside the maternity ward in Taipei, Oct. 25, 2011. (Pichi Chuang/Reuters)

Neelum, 19, lies with her newborn at a maternity ward in Karachi, Oct. 25, 2011. (Insiya Syed/Reuters)

Twelve-day-old Fatima is held up by her grandmother at a maternity ward in Karachi, Oct. 25, 2011.(Insiya Syed/Reuters)

Nurses stand around a newborn baby lying in a trolley inside a maternity ward in Karachi, Oct. 25, 2011. (Insiya Syed/Reuters)

A nurse checks Yang Huiqing before she has a cesarean section in Ruijin Hospital in Shanghai, Oct. 24, 2011. Yang and her husband Chen Yiming, both born under the one-child policy, had their first baby as the world population was about to reach the seven billion mark. (Carlos Barria/Reuters)

Chen Yiming talks to his wife as she is carried to the operating room before a cesarean section in Ruijin Hospital in Shanghai, Oct. 24, 2011. China, the world's most populated country with more that 1.34 billion people, introduced a law that limits most urban families to one child. The policy is meant to avoid over-population, but as families shrink and the population structure moves towards an inverted pyramid, many demographers worry that a shrinking pool of young people won't be able to support and care for their elders. (Carlos Barria/Reuters)

A nurse speaks to Yang Huiqing before she has a cesarean section in Shanghai, Oct. 24, 2011. Yang and her husband Chen Yiming, both born under the one-child policy. (Carlos Barria/Reuters)

Nurses watch as Yang Huiqing has a cesarean section, October 24, 2011. Yang and her husband Chen Yiming, both born under the one-child policy, had their first baby as the world population was about to reach the seven billion mark. China introduced a law that limits most urban families to one child. The policy is meant to avoid over-population. (Carlos Barria/Reuters)

A doctor holds up the newborn baby of Yang Huiqing, Oct. 24, 2011. (Carlos Barria/Reuters)Chen Yiming waits in the lobby of the delivery room, Oct. 24, 2011. (Carlos Barria/Reuters)

Chen Yiming waits in the lobby of the delivery room, Oct. 24, 2011. (Carlos Barria/Reuters)

Yang Huiqing meets her baby after a cesarean section in Ruijin Hospital in Shanghai, Oct. 24, 2011. (Carlos Barria/Reuters)

Chen Yiming touches his newborn baby's hand, Oct. 24, 2011. (Carlos Barria/Reuters) (Carlos Barria/Reuters)

Wang Hui Qio and Guo Hua Li, grandmothers of the newborn baby of Yang Huiqing, celebrate the birth in Ruijin Hospital in Shanghai, Oct. 24, 2011. (Carlos Barria/Reuters)

Yang Huiqing, 26, texts her husband as she rests in the delivery room in Ruijin Hospital in Shanghai, Oct. 24, 2011. (Carlos Barria/Reuters)

Pregnant women lie on beds while waiting to give birth in the maternity ward of the Central Obstetrics Hospital in Hanoi, Oct. 27, 2011. (Kham/Reuters)

Doctors help Le Thi Nga, 26, give birth in the maternity ward of the Central Obstetrics Hospital in Hanoi, Oct. 27, 2011. (Kham/Reuters)

Newborn babies lie on trolleys at the Central Obstetrics Hospital in Hanoi, Oct. 27, 2011.(Kham/Reuters)

The Central Obstetrics Hospital's 15,966th newborn baby lies on a trolley in Hanoi, Oct. 27, 2011. (Kham/Reuters)

A nurse cleans the baby of Le Thi Nga, just after birth, in the maternity ward of the Central Obstetrics Hospital in Hanoi, Oct. 27, 2011. (Kham/Reuters)

A newborn baby lies in a warming box in the special care ward at the Central Obstetrics Hospital in Hanoi, Oct. 27, 2011. The United Nation projects the world's population will reach 7 billion on October 31, 2011. (Kham/Reuters)