- The climate of East Asia is both similar to and different from that of Europe and the United States. It is similar in that it is a temperate climate, with colder winters and warm summers. It is different in that most of the rainfall occurs during the warm summer months, rather than during the winter months. This abundant water supply during the warm growing season allows for intensive agriculture, with two and sometimes three crop cycles per year. (The summer rains are borne by monsoon winds, determined by the land mass of Central Asia: in the winter, the cold, dry heavy air over Central Asia flows outward toward the sea; in the summer months, the warm air over the Central Asian land mass rises and cooler, moist air from the ocean flows back bringing rainfall over the land.) [See Notes section, below]
- Rice, the primary cereal crop grown in East Asia, is particularly suited to the warm, wet growing season. (Rice is best grown in flooded fields, or paddies.) Since rice produces a much higher yield per acre than does a crop such as wheat, it can support a much greater population per acre than does wheat. Climate, agriculture, and population size are closely related in East Asia where large population densities have existed throughout history. [See Notes section, below]
- The distinctive geographical characteristics of China (continental), Japan (insular), Korea (peninsular), and Vietnam (peninsular/continental) affected the historical development of each country.
- Chinese civilization (written script, Confucian thought, and Buddhism that had come to China from India) spread northward to the Korean peninsula and then to the islands of Japan, and southward to what is today northern Vietnam -- engendering dialogue and exchange among the four countries of the East Asian cultural sphere. The climate of all four countries supports wet rice agriculture.
- Chinese civilization first developed along the major river systems of the Yellow River (Huang He) and then the Yangzi (Chang Jiang) in eastern China. China's population and agricultural settlement spread southward through history and remain concentrated today in the central and southern regions of east China, south of the Great Wall, in an area known as "China proper."
- The west and north of what is China today are dominated by mountains, steppe lands, plateaus, and deserts. These areas were predominantly settled in the past by nomadic peoples. Over the course of Chinese history, nomadic peoples from China's border regions have often intruded upon the settled, agricultural civilization of "core" China, and in recent centuries, Chinese farmers have settled in the interior regions.
- Japan is an island country composed of four main islands and thousands of smaller ones. The main islands are, at their closest point, 120 miles off the coast of Asia. Japan's geographic distance from the Asian mainland is cited as one reason why Japan has been able so consciously and deliberately to borrow and adapt innovations from other civilizations and to forge a strong cultural identity.
- China and Japan are two of the world's most populous countries. China, which ranks #1 among countries in population, supports approximately one-fifth of the world's population but has only 7% of the world's arable land. Japan is the tenth most populous country in the world; its land area is comparable to that of Italy or California. Japan's population in 2010 was approximately 127,000,000, less than half that of the United States, which had approximately 309,000,000 people. China's population is nearly five times larger than that of the United States.
- The Japanese islands lack most of the natural resources necessary to support an industrialized economy. These resources must be imported.
- The Korean peninsula shares borders with China and Russia; it is the portion of the Asian mainland closest to the Japanese islands. The Korean peninsula is well endowed with natural resources. South Korea ranked #25 among the countries of the world in population, with approximately 49,000,000 people in 2010. North Korea ranked #49, with approximately 24,000,000 people in 2010. If the population of the two Koreas is combined, the peninsula would have a total of approximately 73,000,000 people and rank #18 among world countries – with more people than Turkey, France, or England.
- Vietnam is divided naturally into northern and southern areas, divided by mountains that reach the sea in the central area. Both the northern and southern regions are in turn dominated by a river delta: that of the Red River in the north and of the Mekong River in the south. Historically, different groups held power respectively in the northern, central, and southern regions of Vietnam. Vietnam ranked #13 among the countries of the world in population, with approximately 85,000,000 people in 2010, a population larger than that of Germany.
Notes: For more information on the climate of East Asia in comparison with that of India and Europe, see John K. Fairbank, Edwin O. Reischauer, and Albert Craig, East Asia: Tradition and Transformation (Boston: Houghton Mifflin). Please see also, the AFE module devoted to EAST ASIA in GEOGRAPHIC PERSPECTIVE [http://afe.easia.columbia.edu/geography/]