 It is estimated that one @-@ eighth of Earth 's surface is suitable for humans to live on – three @-@ quarters of Earth 's surface is covered by oceans , leaving one quarter as land . Half of that land area is desert ( 14 % ) , high mountains ( 27 % ) , or other unsuitable terrain . The northernmost permanent settlement in the world is Alert , on Ellesmere Island in Nunavut , Canada . ( 82 ° 28 ′ N ) The southernmost is the Amundsen – Scott South Pole Station , in Antarctica , almost exactly at the South Pole . ( 90 ° S ) 
