Science

by By Ciara Nugent / Wallasea Island, U.K.

by Aryn Baker / Mbar Toubab, Senegal

by TIME Staff

by Graça Machel

by Jeffrey Kluger

by Rod McCullom / Undark

by Ban Ki-moon

by Jeffrey Kluger

by Jeffrey Kluger

by Lucas Isakowitz

by Craig Trudell / Bloomberg

by Sanya Mansoor

by Matt Sandy