President Barack Obama watches as Joey Hudy (L), 14, from Phoenix, Arizona pumps the Extreme Marshmallow Cannon he invented, while touring student science fair projects on exhibit in the State Dining Room at the White House February 7, 2012 in Washington, DC. Obama hosted the second White House Science Fair celebrating the student winners of science, technology, engineering and math (STEM) competitions from across the country. (Photo by Molly Riley-Pool/Getty Images)

The #8 DP Starworks Motorsports Ford Rley driven by Enzo Potolicchio, Ryan Dalziel, Alex Popow, Lucas Luhr and Allan McNish runs off the track during the Rolex 24 at Daytona International Speedway on January 28, 2012 in Daytona Beach, Florida. (Photo by John Harrelson/Getty Images)

Director Pawel Pawlikowski holds his Oscar for best foreign language film for “Ida”, with presenters Chiwetel Ejiofor (L) and Nicole Kidman during the 87th Academy Awards in Hollywood, California February 22, 2015. (Photo by Lucy Nicholson/Reuters)

A Southwest Airlines jet takes off from Reagan National Airport with a thunderhead to the east on June 20, 2017 in Alexandria, VA. (Photo by Jonathan Newton/The Washington Post)

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)

An elephant from Earl's Court Circus with a man in its mouth, 1928. P.S. All pictures are presented in high resolution.

A view of trees shrouded in fog on a late summer morning between Tureby and Slimminge on Zealand, Denmark, 10 September 2021. (Photo by Mads Claus Rasmussen/EPA/EFE)

A model presents a creation of Peruvian designer Ani Alvarez Calderon during Fashion Week in Lima, Peru, April 25, 2017. (Photo by Guadalupe Pardo/Reuters)