In this January 27, 2015 photo, penguins walk on the shore of Bahia Almirantazgo in Antarctica. Antarctica “is big and it's changing and it affects the rest of the planet and we can't afford to ignore what's going on down there”, said David Vaughan, science director of the British Antarctic Survey. (Photo by Natacha Pisarenko/AP Photo)

A new book of photos by legendary photographer Weegee shows what industrialized, pre-gentrified New York looked like in the mid-20th century, before the city was crammed with towers and billboards. Here: this combination shows the 1945 photo “Derelict sleeping on the sidewalk outside police headquarters” by Weegee, provided by the International Center of Photography in New York, and a woman walking on the same spot on Wednesday, March 18, 2015. (Photo by AP Photo/Copyright Weegee/The International Center of Photography, Mark Lennihan)

In this September 16, 1983 file photo, actor and bodybuilder Arnold Schwarzenegger shows off his new U.S. citizenship papers as Maria Shriver, daughter of Sargent and Eunice Shriver, looks on at the Shrine Auditorium in Hollywood, Calif. (Photo by Wally Fong/AP Photo)

A migrant holds a placard which reads “No Forced Deportations” as he rides his bicycle at the makeshift camp called “The New Jungle” in Calais, France, September 18, 2015. Around 3,500 migrants and refugees are camped in Calais, fleeing war and poverty in the Middle East, Africa and Asia and now living in the jungle. Most of them are hoping to make the crossing to England. (Photo by Regis Duvignau/Reuters)

A zoo employee carries three-month-old female giant panda cub, born to mother Liang Liang and father Xing Xing, on display to the public for the first time at the national zoo in Kuala Lumpur, Malaysia, November 17, 2015. (Photo by Olivia Harris/Reuters)

A child dressed in an imitation dress of army soldier enjoys a cold drink during a religious procession in Amritsar, India, 15 December 2015. The religious procession was taken out on the eve of the martyrdom day of the 9th Guru or Master of the Sikhs Sri Guru Tegh Bahadur Ji. Guru Tegh Bahadur was executed for not converting to Islam on the orders of Mughal Emperor Aurangzeb in Delhi in 1675 AD. The place of this occurrence is called Gurudwara Sis Ganj at Delhi. Guru Tegh Bahadur the youngest of the five sons of Guru Hargobind was born in Amritsar in 1621. (Photo by Raminder Pal Singh/EPA)

According to the U.S. government, Moldova, one of the poorest countries in Europe, depends on about $1.6 billion annually sent back from the roughly one million Moldovans who left for work in in Europe, Russia, and other former Soviet Bloc countries. Photographer Myriam Meloni went to Moldova to document what she refers to as “social orphans” – children whose parents have emigrated to another country in search of a job and a better future for their families. Here: Lulia is seen washing dishes in her grandmother's house, where she lives. (Photo by Myriam Meloni)

A girl sits on railway tracks at a makeshift camp for refugees and migrants at the Greek-Macedonian border near the village of Idomeni, Greece, March 19, 2016. (Photo by Alkis Konstantinidis/Reuters)