Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and comprises 30% of its land area. With approximately 4.3 billion people, it hosts 60% of the world's current human population. Asia has a high growth rate in the modern era. For instance, during the 20th century, Asia's population nearly quadrupled.
Asia is defined as comprising the eastwards four-fifths of Eurasia. It is located to the east of the Suez Canal, the Ural river, and the Ural Mountains, and south of the Caucasus Mountains (or the Kuma-Manych Depression) and the Caspian and Black Seas. It is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean and on the north by the Arctic Ocean.
Given its size and diversity, Asia – a toponym dating back to classical antiquity – "is more a cultural concept" incorporating diverse regions and peoples than a homogeneous physical entity. Asia differs very widely among and within its regions with regard to ethnic groups, cultures, environments, economics, historical ties and government systems.
Asia has extremely diverse climates and geographic features. Climates range from arctic and subarctic in Siberia to tropical in southern India and Southeast Asia. It is moist across southeast sections, and dry across much of the interior. Some of the largest daily temperature ranges on Earth occur in western sections of Asia. The monsoon circulation dominates across southern and eastern sections, due to the presence of the Himalayas forcing the formation of a thermal low which draws in moisture during the summer. Southwestern sections of the continent are hot.
Siberia is one of the coldest places in the Northern Hemisphere, and can act as a source of arctic air masses for North America. The most active place on Earth for tropical cyclone activity lies northeast of the Philippines and south of Japan. The Gobi Desert is in Mongolia and the Arabian Desert stretches across much of the Middle East. The Yangtze River in China is the longest river in the continent. The Himalayas between India and China is the tallest mountain range in the world. Tropical rainforests stretch across much of southern Asia and coniferous and deciduous forests lie farther north.
East Asia had by far the strongest overall Human Development Index (HDI) improvement of any region in the world, nearly doubling average HDI attainment over the past 40 years, according to the report’s analysis of health, education and income data. China, the second highest achiever in the world in terms of HDI improvement since 1970, is the only country on the “Top 10 Movers” list due to income rather than health or education achievements. Its per capita income increased a stunning 21-fold over the last four decades, also lifting hundreds of millions out of income poverty. Yet it was not among the region’s top performers in improving school enrolment and life expectancy.
Nepal, a South Asian country, emerges as one of the world’s fastest movers since 1970 mainly due to health and education achievements. Its present life expectancy is 25 years longer than in the 1970s. More than four of every five children of school age in Nepal now attend primary school, compared to just one in five 40 years ago.
Japan and South Korea ranked highest among the countries grouped on the HDI (number 11 and 12 in the world, which are in the “very high human development” category), followed by Hong Kong (SAR) and Singapore. Afghanistan ranked lowest amongst Asian countries out of the 169 countries assessed.
Asia is home to several language families and many language isolates. Most Asian countries have more than one language that is natively spoken. For instance, according to Ethnologue, more than 600 languages are spoken in Indonesia, more than 800 languages spoken in India, and more than 100 are spoken in the Philippines. China has many languages and dialects in different provinces.
Almost all Asian religions have philosophical character and Asian philosophical traditions cover a large spectrum of philosophical thoughts and writings. Indian philosophy includes Hindu philosophy and Buddhist philosophy. They include elements of nonmaterial pursuits, whereas another school of thought from India, Carvaka, preached the enjoyment of material world. As of 2012, Hinduism has around 1.1 billion adherents. The faith represents around 25% of Asia's population and is the second largest religion in Asia. However, it is mostly concentrated in south Asia. Islam is the largest religion in Asia. Christianity is also present in most Asian countries.
Asian mythology is complex and diverse. The story of the Great Flood for example, as presented to Christians in the Old Testament, is first found in Mesopotamian mythology, in the Epic of Gilgamesh. Hindu mythology tells about an Avatar of the God Vishnu in the form of a fish who warned Manu of a terrible flood. In ancient Chinese mythology, Shan Hai Jing, the Chinese ruler Da Yu, had to spend 10 years to control a deluge which swept out most of ancient China and was aided by the goddess Nüwa who literally fixed the broken sky through which huge rains were pouring.