A girl looks up to the sky after hearing the sound of shelling as she sits on a toy pony in the playground of Al-Tawheed school in Aleppo, Syria on Jan. 1.

Children play in the playground of Al-Tawheed school in Aleppo on Jan. 1.

Children play with a toy car in the playground of Al-Tawheed school in Aleppo on Jan. 1.

Children sit on school benches at Al-Tawheed school in Aleppo on Jan. 1.

Children attend a class at Al-Tawheed school in Aleppo on Jan. 1.

Seven-year-old Achta stands in the door of her family's cooking hut, as her mother prepares dinner over a wood fire by the light of a flashlight, in the village of Louri, in the Mao region of Chad, Nov. 1. Achta's birth seven years ago coincided with the first major drought to hit the Sahel this decade. Climate change has meant that the normally once-a-decade droughts are now coming every few years. The droughts decimated her family's herd. With each dead animal, they ate less. (AP Photo/Rebecca Blackwell)

A woman walks toward a well through clouds of dust raised by cattle in the wadi outside Louri village in the Mao region of Chad, Nov. 1. For generations, the people of this bone-dry region lived off their herds, but climate change has meant that the normally once-a-decade droughts are now coming every few years.

Teacher Djobelsou Guidigui Eloi works with a student at the blackboard in Louri village's school hut in the Mao region of Chad, Nov. 2. Many of the children, unable to read, attempted to pass the lesson by memorizing the sounds and their order on the blackboard. In 2011, 78 boys and girls enrolled in the equivalent of first grade in Chad's school system. Of those children, 42 failed the test to graduate into the next grade, a percentage that almost exactly mirrors the number of children stunted in the county.

Young men walk in the wadi alongside Louri village, in the Mao region of Chad, Nov. 2. Climate change has meant that the normally once-a-decade droughts are now coming every few years, decimating food production.

Health workers measure the height of a boy during a mobile clinic to identify cases of underweight, stunted, or malnourished children, in Michemire, in the Mao region of Chad, Nov. 4.

A boy watches as women pump water from the village borehole in Louri, in the Mao region of Chad, Nov. 3.

A little girl cries as she is weighed as part of a mobile nutrition clinic to examine local children and identify cases of underweight, stunted, or malnourished children, in Michemire, in the Mao region of Chad, Nov. 4.

Children gather under a sole shade tree as they take a break from class outside their schoolhouse made of reeds in the village of Louri, in the Mao region of Chad, Nov. 2.

In this Nov. 1, 2012 photo, 7-year-old Achta, right, walks with her mother Fatme Ousmane in the village of Louri in the Mao region of Chad. Achta's birth seven years ago coincided with the first major drought to hit the Sahel this decade. Climate change has meant that the normally once-a-decade droughts are now coming every few years. The droughts decimated her family's herd. With each dead animal, they ate less. (AP Photo/Rebecca Blackwell)

Seven-year-old Achta looks at the blackboard during class in the village of Louri in the Mao region of Chad, Nov. 2. In this village where malnutrition has become chronic, children have simply stopped growing. In the county that includes Louri, 51.9 percent of children are stunted, one of the highest rates in the world, according to a survey published by UNICEF - more than half the children in the village.

Seven-year-old Achta, her older brother, and their mother Fatme Ousmane share a dinner of rice and meat, a rare treat, leftovers from the recent Eid holiday, in the village of Louri, in the Mao region of Chad. The droughts decimated her family's herd. With each dead animal, they ate less.

Afghan children wind up and collect their takings for the day after scavenging for recyclables at a garbage dump site.

Afghan Pashtun boys, warm themselves by a fire near to a garbage dump site at night.

Girls turning 15 pose in their gowns for photos inside a pink limousine before their debutante ball, in the Mangueira favela, or shantytown, in Rio de Janeiro.

A girl turning 15 pauses to look out the limousine that drove her and other girls to a group debutante ball, organized by the Peacemaker Police Unit program, as the car's interior disco lights illuminate her friend's dress.

A girl rests on the sidewalk in her gown before attending the debutante ball in the Rio de Janeiro shantytown.

A girl turning 15, dances with her friend during a group debutante ball in Rio de Janeiro.

A debutante ball party goer sits on the floor as she adjusts her high heel shoe.

An Egyptian child stands in front of a tire repair shop where he works in Cairo, Egypt. Photo taken on Oct. 2.

An Egyptian girl fills water containers at a pottery workshop in old Cairo. Photo taken on Oct. 18.

An Egyptian child helps his father to load a donkey cart with hay in a farm at the outskirts of Qalyobiya, 27 miles north of Cairo, Egypt. Photo captured on Oct. 17.

An Egyptian child loads a cart with cement bricks in a brick factory at the outskirts of Qalyobiya, 27 miles north of Cairo.

An Egyptian child carries a clay roof tile in a pottery workshop in old Cairo. Photo captured on Oct. 18.

An Egyptian child takes a tea break during his work at a mechanics workshop in Cairo, Egypt. Photo captured Oct. 4.

Anais Nickol, with cerebral palsy, hugs Hershey, a therapeutically trained dog, during a therapy session.

Anais Yisel (L) with cerebral palsy and Josue Salazar with autism lie on top off Fiona, a therapeutically trained dog, during a therapy session at the Colitas Foundation in Panama City.

Afghan jugglers rehearse before the 7th Afghanistan Juggling Championships in Kabul on Aug. 27.

Afghan jugglers preform during the 7th Afghanistan Juggling Championships in Kabul.

Young female Afghan audience members watch a performance during the 7th Afghanistan Juggling Championships in Kabul.

A girl wearing a brace on her leg is assisted by a physical therapist during a hydrotherapy session at the AACD on April 3.

A physical therapist supports Luiza Ezaledo, 2, during a hydrotherapy session on April 2.

Luara Crystal, 5, who suffers from brittle bone disease, lifts a weight next to her physical therapist during a session at the AACD.

Ivan Bevenuto, 4, sits next to his skateboard after taking part in a Capoeira therapy session at the AACD on March 21.

Yara Santos, 9, talks with her mother before a session of physical therapy on March 21.

A nurse plays with a child in an orphanage in Bulembu, Swaziland, on March 1, 2012. [Pictures made available March 23]

Workers renovate the old miners' houses in Bulembu.

Pupils drawing during a school lesson.