A participant, surrounded by red chilli peppers, takes part in a chilli-eating competition at a hot spring in Yichun, Jiangxi province, China on December 9, 2018. (Photo by Chen Fei/China News Service via Reuters)

A visitor to The Brooklands Double Twelve Motorsport Festival admires a 1914 Morgan Three Wheeler in front of a Hawker P1127 prototype jet aircraft on June 18, 2011 in Weybridge, England. Two hundred vintage cars are competing in various races, tests and speed trials over the two day event held at the Brooklands Museum. Brooklands was the world's first purpose-built, permanent motorsport venue that opened in 1907. (Photo by Peter Macdiarmid/Getty Images)

People help a woman overwhelmed by emotion and the heat during the mass funeral, attended by tens of thousands of mourners, of 613 coffins of newly-identified victims of the 1995 Srebrenica massacre at the Potocari cemetery and memorial near Srebrenica on July 11, 2011 in Potocari, Bosnia and Herzegovina. (Photo by Sean Gallup/Getty Images)

(L-R) Zandea,18, and Jessica, 21, pose showing off their clothing backstage during a show featuring OPT jeans December 8, 2011 in Yangon, Myanmar. (Photo by Paula Bronstein /Getty Images)

A competitor poses before the Tough Guy Challenge endurance race on January 27, 2013 in Telford, England. Every year thousands of people run the 8 mile assault course which involves freezing temperatures, fire and ice. (Photo by Michael Regan)

Tourists watch the sunrise and pray outside a church on the summit of Mount Moses, near the city of Saint Catherine, in the Sinai Peninsula, south of Egypt, December 9, 2015. (Photo by Amr Abdallah Dalsh/Reuters)

Tiny pieces of space rocks, called meteorites, are seen burning in the atmosphere over the night sky near Salgótarján, some 109km northeast of Budapest, Hungary, 21 April 2018 (issued 22 April 2018). (Photo by Peter Komka/EPA/EFE)

Global wildlife populations will decline by 67% by 2020 unless urgent action is taken to reduce human impact on species and ecosystems, warns the biennial Living Planet Index report from WWF (World Wide Fund for Nature) and ZSL (Zoological Society of London). From elephants to eels, here are some of the wildlife populations most affected by human activity. Here: The maned wolf is among the large mammals in the Brazilian Cerrado that are threatened by the increasing conversion of grasslands into farmland for grazing and growing crops. (Photo by Ben Cranke/Nature Picture Library/Alamy Stock Photo)