In human geography and in the English-speaking world outside the United States, particularly in Canada, 'North America' and 'North American' can refer to just Canada and the United States together. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population. North America is the third-largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. North America covers an area of about 24,709,000 square kilometres (9,540,000 square miles), about 16.5% of Earth's land area and about 4.8% of its total surface area. Because it is on the North American Tectonic Plate, Greenland is included as a part of North America geographically. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. Map of populous North America showing physical, political and population characteristics as per 2018
