A tower belonging to the Abengoa solar plant at the Solucar solar park is seen in Sanlucar la Mayor, Spain on October 1, 2018. (Photo by Marcelo del Pozo/Reuters)

An Exmoor wild goat silhouetted in the sky over the Bristol Channel at the valley of the Rocks, North Devon, as the UK's heat wave continues on July 19, 2018. (Photo by Paul Silver/South West News Service)

A peformance artist attends an election rally for Cameroon presidential candidate for the opposition Univers party, Cabral Libii in Yaounde, Cameroon 06 October 2018. Africa's oldest president Paul Biya who has been in power since 1982 is up against eight candidates when voters go to the polls 07 October 2018. 6.9 million registered voters will head to the polls but marginalised anglophone separatists in the North West and South West of the country threaten to disrupt the elections. (Photo by Nic Bothma/EPA/EFE)

A Palestinian man argues with an Israeli soldier during clashes over an Israeli order to shut down a Palestinian school near Nablus, in the occupied West Bank, October 15, 2018. (Photo by Mohamad Torokman/Reuters)

Icicles are seen on a handrail along the coast at Donggang business district in Dalian, Liaoning province, China on December 27, 2018. (Photo by Reuters/China Stringer Network)

Australian performers illuminated with real clocks titled “The Time Minder” attend a media preview of the Night Festival in Singapore on August 23, 2017. Singapore's arts and heritage district will be transformed into Singapore largest outdoor performing arts festival to celebrate its 10th year edition Night Festival from August 24 to 26. (Photo by Roslan Rahman/AFP Photo)

Polar bears prepare to feast on the remains of a bowhead whale, harvested legally by whalers during their annual subsistence hunt, just outside the Inupiat village of Kaktovik, Alaska, USA, 10 September 2017. As climate change shrinks their natural habitat, polar bears are turning Kaktovik into their very own sanctuary city. (Photo by Jim Lo Scalzo/EPA/EFE)

A golden pheasant and squirrels are seen in Lushan County of Pingdingshan City, central China's Henan Province, November 14, 2017. (Photo by Liu Xianguo/Xinhua/Barcroft Images)