As per estimations, only one-eighth of Earth's surface is appropriate for inhabitation of human beings. Oceans cover three quarters of the surface, and the remaining one-quarter of land is also either desert (14%), high mountains (27%), or other unsuitable terrains. Alert, on Ellesmere Island in Nunavut, Canada is the northernmost permanent settlement at lat (82°28′N), whereas Amundsen–Scott South Pole Station, in Antarctica is the southernmost point suitable for living, at lat (90°S).
The 206 listed states of the United Nations are divided into three categories: 193 member states, 2 observer states, and 11 other states. The 191 sovereign states, are the countries whose sovereignty is official, and no disputes linger. There are 15 states under the category of “sovereignty dispute”. These are 5 member states, 1 observer state and 9 other states.