A woman walks through flood water during heavy downpour at a street in Genoa, Italy, 10 October 2014. At least one person died due to flooding after heavy rains caused the Bisagno river, which runs through Genoa city to overflow. Part of the city was in black-out with flooded streets and parked cars dragged away by the water's force. (Photo by Luca Zennaro/EPA)

A Naga sadhu, or naked Hindu holy man, pauses inside a tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Thursday, August 27, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Bernat Armangue/AP Photo)

“Asaro from the Eastern Highlands”. The mudmen could not cover their faces with mud because the people of Papua New Guinea thought that the mud from the Asaro river was poisonous. So instead of covering their faces with this alleged poison, they made masks from pebbles that they heated and water from the waterfall, with unusual designs such as long or very short ears either going down to the chin or sticking up at the top, long joined eyebrows attached to the top of the ears, horns and sideways mouths. (Photo and caption by Jimmy Nelson)

Snorkellers approach an adult manatee at Three Sisters Spring, Crystal River, Florida. You might imagine that coming face to face with one of these enormous underwater mammals would cause some concern. However, the likelihood is that the rotund creature just wants you to scratch its belly while it floats around happily, as world-renowned underwater photographer Alex Mustard discovered. (Photo by Alexander Mustard/Barcroft Media)

Ebiowei, 48, carries an empty oil container on his head to a place where it would be filled with refined fuel at an illegal refinery site near river Nun in Nigeria's oil state of Bayelsa November 27, 2012. Locals in the industry say workers can earn $50 to $60 a day. Thousands of people in Nigeria engage in a practice known locally as “oil bunkering” – hacking into pipelines to steal crude then refining it or selling it abroad. The practice, which leaves oil spewing from pipelines for miles around, managed to lift around a fifth of Nigeria's two million barrel a day production last year according to the finance ministry. (Photo by Akintunde Akinleye/Reuters)

A sadhu, or a Hindu holy man, blesses a devotee as he smokes marijuana at a transit camp on the way to Gangasagar, in Kolkata, India, Sunday, January 7, 2018. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan. 14. (Photo by Bikas Das/AP Photo)

A horse is ridden out of the River Eden after being washed on the first day of the Appleby Horse Fair on June 7, 2018 in Appleby, England. The fair is an annual gathering for Gypsy, Romany and travelling communities. The event has existed under the protection of a charter granted by James II since 1685 and it remains one of the key meeting points for these communities. Around 10,000 travellers are expected to attend the event who traditionally come to buy and sell horses and it offers an opportunity for the traveller community to come together to celebrate their heritage and culture. (Photo by Ian Forsyth/Getty Images)

A butterfly flies into the jaws of a crocodile inhabiting the Tarcoles River, the most polluted basin in Central America and one of the most polluted in Latin America, in the place of Tarcoles, province of Puntarenas, Costa Rica, 05 June 2018. Costa Rica, a country recognized worldwide for its environmental policies, seeks to be a leader in the replacement of single-use plastic with renewable and compostable alternatives, despite its lag in terms of recycling and integrated waste management. (Photo by Jeffrey Arguedas/EPA/EFE)