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)

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)

Hannah Maule-ffinch, “Wild Swimmers”, 2020, Hinksey Lake, Oxfordshire. Category: People. The series Wild Swimmers explores how humans are strongest when coming together in the face of adversity. In this photo, Emma and Emma have an amazing bond and friendship, built through their daily ritual of cold swimming in often bracing conditions. (Photo by Hannah Maule-ffinch/Earth Photo 2022)

A guard dog in the suburbs of Yakutsk, Russia, considered to be the coldest city in the world, January 2014. (Photo by Amos Chapple/REX Features)

The newly-discovered gaseous planet Kepler-16b orbits it's two stars. NASA's Kepler Mission discoverd the world orbiting two Stars, the larger a K dwarf and the smaller a red dwarf. (Photo by NASA/JPL-Caltech/T. Pyle via Getty Images)

In this artist illustration handout from the National Aeronautics and Space Administration (NASA), the Upper Atmosphere Research Satellite (UARS) is seen. According to NASA, the 12,500 pound satellite will fall from orbit into earth's atmosphere anytime between September 22 through 24. It is estimated that the space craft will break up into about 100 pieces, with an estimated 26 of which could hit the earth over a possible 500 mile debris field. (Illustration by NASA via Getty Images)