April 11, 2013
From The Strange Beauty of Salt Mines, one of 31 photos. One of the colorful brine pools that are part of a lithium salt pilot plant on the Uyuni salt lake, which holds the world’s largest reserve of lithium, located at 3,656 meters (11,995 ft) above sea level in southwestern Bolivia, on November 5, 2012. (Reuters/David Mercado)

From The Strange Beauty of Salt Mines, one of 31 photos. One of the colorful brine pools that are part of a lithium salt pilot plant on the Uyuni salt lake, which holds the world’s largest reserve of lithium, located at 3,656 meters (11,995 ft) above sea level in southwestern Bolivia, on November 5, 2012. (Reuters/David Mercado)

April 9, 2013
From Signs of Spring, one of 33 photos. Stella Ferruzola, 3, poses with a Blue Morpho butterfly on her nose at the Sensational Butterflies Exhibition at the Natural History Museum in London, on March 25, 2013. (Reuters/Luke MacGregor)

From Signs of Spring, one of 33 photos. Stella Ferruzola, 3, poses with a Blue Morpho butterfly on her nose at the Sensational Butterflies Exhibition at the Natural History Museum in London, on March 25, 2013. (Reuters/Luke MacGregor)

March 25, 2013
From Earth Hour 2013, one of 25 photo pairs. Leifeng Pagoda, behind the West Lake before (left) and with its lights off (right), during Earth Hour in Hangzhou, Zhejiang province, China, on March 23, 2013. Earth Hour, an hour when everyone around the world is asked to turn off lights from 8.30 p.m. local time, is organized by the World Wide Fund for Nature (WWF), and is meant as a show of support for tougher action to confront climate change. (Reuters/Chance Chan)

From Earth Hour 2013, one of 25 photo pairs. Leifeng Pagoda, behind the West Lake before (left) and with its lights off (right), during Earth Hour in Hangzhou, Zhejiang province, China, on March 23, 2013. Earth Hour, an hour when everyone around the world is asked to turn off lights from 8.30 p.m. local time, is organized by the World Wide Fund for Nature (WWF), and is meant as a show of support for tougher action to confront climate change. (Reuters/Chance Chan)

March 22, 2013
From China’s Toxic Water, one of 17 photos. On World Water Day, a look at part of southern China. Here, a woman fetches water from the Yangtze river. Fifty families of fishermen live in Yanglingang village. They fish for their livelihood and have been drinking water from the Yangtze for decades. In the last few years, however, the river has been significantly polluted, and the fishermen noticed that the water has a strange flavor. Since 2003, factory construction has erupted all around Yanglingang. Today the little fishing village is surrounded by power plants, paper-making factories, and chemical plants. (© Lu Guang/Greenpeace)

From China’s Toxic Water, one of 17 photos. On World Water Day, a look at part of southern China. Here, a woman fetches water from the Yangtze river. Fifty families of fishermen live in Yanglingang village. They fish for their livelihood and have been drinking water from the Yangtze for decades. In the last few years, however, the river has been significantly polluted, and the fishermen noticed that the water has a strange flavor. Since 2003, factory construction has erupted all around Yanglingang. Today the little fishing village is surrounded by power plants, paper-making factories, and chemical plants. (© Lu Guang/Greenpeace)

March 13, 2013
From North Dakota’s Oil Boom, one of 30 photos. Roughneck Brian Waldner, covered in mud and oil on a True Company oil drilling rig outside Watford, North Dakota, on October 20, 2012. Thousands of people have flooded into North Dakota to work in state’s oil drilling boom. (Reuters/Jim Urquhart)

From North Dakota’s Oil Boom, one of 30 photos. Roughneck Brian Waldner, covered in mud and oil on a True Company oil drilling rig outside Watford, North Dakota, on October 20, 2012. Thousands of people have flooded into North Dakota to work in state’s oil drilling boom. (Reuters/Jim Urquhart)

February 27, 2013
From A Siberian Winter, one of 31 photos. Here, a man walks through a tunnel formed by ice crystals from surrounding permafrost, outside the village of Tomtor in the Oymyakon valley in northeast Russia, on January 28, 2013. The coldest temperatures in the northern hemisphere since the beginning of the 20th century were recorded in the Oymyakon valley, known as the northern “Pole of Cold”, reaching a temperature of -67.8 degrees Celsius (-90 degrees Fahrenheit) in 1933. (Reuters/Maxim Shemetov)

From A Siberian Winter, one of 31 photos. Here, a man walks through a tunnel formed by ice crystals from surrounding permafrost, outside the village of Tomtor in the Oymyakon valley in northeast Russia, on January 28, 2013. The coldest temperatures in the northern hemisphere since the beginning of the 20th century were recorded in the Oymyakon valley, known as the northern “Pole of Cold”, reaching a temperature of -67.8 degrees Celsius (-90 degrees Fahrenheit) in 1933. (Reuters/Maxim Shemetov)

February 9, 2013
From Northeast Slammed by Blizzard, one of 28 photos. Ice clings to Ken Anderson’s eyebrows and mustache as he uses a snowblower during a blizzard, on February 9, 2013, in Portland, Maine. The storm dumped more than 30 inches of snow as of Saturday afternoon, breaking the local record for the biggest storm. (AP Photo/Robert F. Bukaty)

From Northeast Slammed by Blizzard, one of 28 photos. Ice clings to Ken Anderson’s eyebrows and mustache as he uses a snowblower during a blizzard, on February 9, 2013, in Portland, Maine. The storm dumped more than 30 inches of snow as of Saturday afternoon, breaking the local record for the biggest storm. (AP Photo/Robert F. Bukaty)

January 10, 2013
From Wintry Weather: Middle East Edition, one of 32 photos. Boys play in the courtyard of the Sultanahmet mosque, known as the Blue mosque, during a snow storm in Istanbul, Turkey, on January 8, 2013. (Reuters/Murad Sezer)

From Wintry Weather: Middle East Edition, one of 32 photos. Boys play in the courtyard of the Sultanahmet mosque, known as the Blue mosque, during a snow storm in Istanbul, Turkey, on January 8, 2013. (Reuters/Murad Sezer)

October 24, 2012
From Fall Is in the Air, Part II, one of 32 photos. Here, three year-old Annie Wood rides her scooter in front of changing autumn leaves in Sheffield Park Gardens near Haywards Heath in southern England, on October 17, 2012. (Reuters/Luke MacGregor)

From Fall Is in the Air, Part II, one of 32 photos. Here, three year-old Annie Wood rides her scooter in front of changing autumn leaves in Sheffield Park Gardens near Haywards Heath in southern England, on October 17, 2012. (Reuters/Luke MacGregor)

August 28, 2012
From The Drought of 2012, one of 36 photos. Here, rancher Gary Wollert pauses before heading out for work near Eads, on the plains of eastern Colorado, on August 23, 2012. The nation’s severe drought has been especially hard on cattlemen, made worse when Congress recessed for 5 weeks without passing disaster relief legislation. Most of the high plains areas of eastern Colorado and virtually all of Nebraska and Kansas are still in extreme or exceptional drought, despite recent lower temperatures. (John Moore/Getty Images)

From The Drought of 2012, one of 36 photos. Here, rancher Gary Wollert pauses before heading out for work near Eads, on the plains of eastern Colorado, on August 23, 2012. The nation’s severe drought has been especially hard on cattlemen, made worse when Congress recessed for 5 weeks without passing disaster relief legislation. Most of the high plains areas of eastern Colorado and virtually all of Nebraska and Kansas are still in extreme or exceptional drought, despite recent lower temperatures. (John Moore/Getty Images)

June 20, 2012
From Rio+20, one of 37 photos. An indigenous child from Kayapo tribe attends first indigenous assembly for the Rio+20 Conference at Kari-Oca village in Rio de Janeiro, on June 14, 2012. Indigenous people from around the world are visiting the village for the Rio+20 United Nations Conference on Sustainable Development. (Reuters/Ricardo Moraes)

From Rio+20, one of 37 photos. An indigenous child from Kayapo tribe attends first indigenous assembly for the Rio+20 Conference at Kari-Oca village in Rio de Janeiro, on June 14, 2012. Indigenous people from around the world are visiting the village for the Rio+20 United Nations Conference on Sustainable Development. (Reuters/Ricardo Moraes)

April 23, 2012
From Images of Earth From Above, one of 39 photos. A view of Earth, the stars, and red and green auroras above cities in western North America, as seen from the International Space Station, on February 19, 2012. (NASA)

From Images of Earth From Above, one of 39 photos. A view of Earth, the stars, and red and green auroras above cities in western North America, as seen from the International Space Station, on February 19, 2012. (NASA)

April 11, 2012
From The Nenets of Siberia, one of 17 photos. Nenets herders move seasonally with their reindeer, traveling along ancient migration routes. During the winter, when temperatures can plummet to -50C, most Nenets graze their reindeer on moss and lichen pastures in the southern forests, or taiga. In the summer months, when the midnight sun turns night into day, they leave the larch and willow trees behind to migrate north. By the time they have crossed the frozen waters of the Ob River and reached the treeless tundra on the shores of the Kara Sea, they might have traveled up to 1,000 km. (© Steve Morgan)

From The Nenets of Siberia, one of 17 photos. Nenets herders move seasonally with their reindeer, traveling along ancient migration routes. During the winter, when temperatures can plummet to -50C, most Nenets graze their reindeer on moss and lichen pastures in the southern forests, or taiga. In the summer months, when the midnight sun turns night into day, they leave the larch and willow trees behind to migrate north. By the time they have crossed the frozen waters of the Ob River and reached the treeless tundra on the shores of the Kara Sea, they might have traveled up to 1,000 km. (© Steve Morgan)

March 22, 2012
From World Water Day, one of 36 photos. A therapist from the Gezenguz (Rascal) Foundation works with an infant during an underwater nerve therapy session in Budapest, on October 27, 2011. Infants and children who have birth injuries and congenital developmental conditions or diseases seek rehabilitation at the foundation. (Reuters/Ferenc Redei)

From World Water Day, one of 36 photos. A therapist from the Gezenguz (Rascal) Foundation works with an infant during an underwater nerve therapy session in Budapest, on October 27, 2011. Infants and children who have birth injuries and congenital developmental conditions or diseases seek rehabilitation at the foundation. (Reuters/Ferenc Redei)

March 21, 2012
From World Water Day, one of 36 photos. Here, a journalist takes a sample of polluted red-colored water in the Jianhe River in Luoyang, Henan province, China, on December 13, 2011. According to local media, the sources of the pollution were two illegal chemical plants discharging their production waste water into the rain sewer pipes. (Reuters/China Daily)

From World Water Day, one of 36 photos. Here, a journalist takes a sample of polluted red-colored water in the Jianhe River in Luoyang, Henan province, China, on December 13, 2011. According to local media, the sources of the pollution were two illegal chemical plants discharging their production waste water into the rain sewer pipes. (Reuters/China Daily)