Aavikoituminen

By USDA emp­loy­ee [Pub­lic do­main], via Wi­ki­me­dia Com­mons; http://up­lo­ad.wi­ki­me­dia.org/wiki­pe­dia/com­mons/6/68/De­ser­ti­fi­ca­ti­on_map.png

By USDA emp­loy­ee [Pub­lic do­main], via Wi­ki­me­dia Com­mons; http://up­lo­ad.wi­ki­me­dia.org/wiki­pe­dia/com­mons/6/68/De­ser­ti­fi­ca­ti­on_map.png

By USDA emp­loy­ee [Pub­lic do­main], via Wi­ki­me­dia Com­mons; http://up­lo­ad.wi­ki­me­dia.org/wiki­pe­dia/com­mons/6/68/De­ser­ti­fi­ca­ti­on_map.png

By USDA emp­loy­ee [Pub­lic do­main], via Wi­ki­me­dia Com­mons; http://up­lo­ad.wi­ki­me­dia.org/wiki­pe­dia/com­mons/6/68/De­ser­ti­fi­ca­ti­on_map.png

By USDA emp­loy­ee [Pub­lic do­main], via Wi­ki­me­dia Com­mons; http://up­lo­ad.wi­ki­me­dia.org/wiki­pe­dia/com­mons/6/68/De­ser­ti­fi­ca­ti­on_map.png

A com­po­si­te of ima­ges sho­wing the di­mi­nis­hing en:Lake Chad from 1973 to 2001.File:Shrin­king­La­keC­had-1973-1997-EO.jpg; NASA; Pub­lic Do­main

A com­po­si­te of ima­ges sho­wing the di­mi­nis­hing en:Lake Chad from 1973 to 2001.File:Shrin­king­La­keC­had-1973-1997-EO.jpg; NASA; Pub­lic Do­main

A com­po­si­te of ima­ges sho­wing the di­mi­nis­hing en:Lake Chad from 1973 to 2001.File:Shrin­king­La­keC­had-1973-1997-EO.jpg; NASA; Pub­lic Do­main