A dog walker on Longsands beach before sunrise in Tynemouth, UK on April 1, 2016. (Photo by Owen Humphreys/PA Wire)

A girl plays in the Eshash el-Sudan slum in the Dokki neighbourhood of Giza, south of Cairo, Egypt September 2, 2015. Residents of the slum clashed with police in late August, when about 50 ramshackle huts were destroyed and at least 20 people were injured by teargas, local media reported, as authorities attempt to clear the area and rehouse residents. The slum dwellers, some of whom have called Eshash el-Sudan home for 50 years, say there are not enough apartments built nearby to house them. The residents of the slum eke out a living by disposing of rubbish or baking bread. Schooling is too expensive for most of their children, who play with salvaged rubbish amid shacks made out of discarded wood and leather. (Photo by Amr Abdallah Dalsh/Reuters)

A general view of the sunrise over Hawes, Wensleydale, UK on November 24, 2014. (Photo by Neil Squires/PA Wire)

A woman struggles with an umbrella in the wind and rain while walking in Derby city centre, on December 23, 2013. (Photo by Rui Vieira/PA Wire)

Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

Undated David Yarrow handout photo of a gorilla as the self-taught wildlife photographer promotes his book, Encounter. (Photo by David Yarrow/Clearview/PA Wire)

Handout photo dated March 20, 2015 issued by Chester Zoo of lemurs looking at the eclipse over Chester Zoo. (Photo by Steve Rawlins/PA Wire/Chester Zoo)

Members of the Royal Navy respond to a simulated fire in a Vanguard-class submarine control room training facility at Clyde naval base in Faslane, Scotland on January 21, 2016. (Photo by Photograph: Danny Lawson/PA Wire)