On approximately October 31st, 2011, the population of the earth is expected to reach seven billion people. By the year 2045, we may have nine billion. National Geographic magazine is giving us a year-long series of articles, photo galleries, and interactive features focused on this population milestone. Can our planet take the strain? What can we do to ease the demands on resources? These images are from National Geographic magazine's new "7 Billion" app, based on its year-long series on world population, now available as a free app for iPad.
*


Photo ©Jonas Bendiksen/National Geographic
Population: 7 Billion January 2011

Venezuela Sharing a hillside with high-rise apartment dwellers, children dance at a shop in one of the squatter communities that ring Caracas, a city of three million. One in seven people on Earth lives in slums today. Providing them with better housing and education will be one of the great challenges facing a world of seven billion people and counting.
*



Photo ©Randy Olson/National Geographic
Population: 7 Billion January 2011

India Its steaming streets crammed with vendors, pedestrians, and iconic Ambassador taxis, Kolkata throbs with some 16 million people—and more pour in every day from small towns. In 1975 only three cities worldwide topped ten million. Today 21 such mega cities exist, most in developing countries, where urban areas absorb much of the globe's rising population.
*


Photo ©Randy Olson/National Geographic
Population: 7 Billion January 2011

Spain Immigrants like these Indians at a Sikh festival in Barcelona are bolstering Europe's stagnant population growth rate. Around the world, the childbearing decisions of young women will determine whether global population stabilizes or not. Research shows that the more education a woman receives, the fewer children she is likely to have.
*


Photo ©John Stanmeyer/National Geographic
Population: 7 Billion January 2011

United States Bundled newborns on September 1, 2010, are arranged for a portrait at Orlando's Winnie Palmer Hospital, the second busiest birth facility in the U.S. Unusual among industrial nations, the U.S. has a comparatively high fertility rate, due in part to the significant rate of teenage pregnancies and a steady influx of immigrants. By 2050 America's population is expected to top 400 million.
*


Photo ©Jonas Bendiksen/National Geographic
Bangladesh May 2011

Taxi boats called kheya nouka cross the Buriganga River to Sadar Ghat, Dhaka's main boat terminal, providing transport in one of the world's most densely populated cities. Low-lying Dhaka is among those most at risk from rising seas.
*


Photo ©Jonas Bendiksen/National Geographic
Bangladesh May 2011

At a Breaking Point: Dhaka slums such as Korail (foreground) are bursting with environmental refugees, putting more pressure on a city laid low by aging infrastructure, intense poverty, and frequent flooding.
*


Photo ©John Stanmeyer/National Geographic
Brazil's Girl Power September 2011

The Shrinking Family
The seven children of 61-year-old Maria do Livramento Braz (left, seated in their midst) of Rio are a reminder of Brazil's once high fertility rate. The number of kids per woman has plummeted since the 1960s. Working-class families now aspire to the middle-class lifestyle—and family size—of Maria Corrêa de Oliveira (right, seated), a Rio psychoanalyst. She and her husband have only Henrique, 8, and Diana, 12.
*


Photo ©Pascal Maitre/National Geographic
Africa's Albertine Rift November 2011

Forests are thinning out too, as hardwood trees are turned into charcoal, filling the bags of men careering toward a Congo market.
*

You'll find links to all the articles in National Geographic's year-long series at the 7 Billion hub. NatGeo also produced videos about the population growth called 7 Billion and Are You Typical?