Eurasia /jʊˈreɪʒə/ is the combined continental landmass of Europe and Asia. The term is a portmanteau of its constituent continents. Located primarily in the Northern and Eastern Hemispheres, it is bordered by the Atlantic Ocean to the west, the Pacific Ocean to the east, the Arctic Ocean to the north, and by Africa, the Mediterranean Sea, and the Indian Ocean to the south. The division between Europe and Asia as two different continents is a historical and cultural construct, with no clear physical separation between them; thus, in some parts of the world, Eurasia is recognized as the largest of five or six continents. In geology, Eurasia is often considered as a single rigid megablock. However, the rigidity of Eurasia is debated based on the paleomagnet data.
Eurasia covers around 55,000,000 square kilometres (21,000,000 sq mi), or around 36.2% of the Earth's total land area. The landmass contains around 5.0 billion people, equating to approximately 70% of the human population. Humans first settled in Eurasia between 60,000 and 125,000 years ago. Some major islands, including Great Britain, Iceland, and Ireland, and those of Japan, the Philippines and Indonesia, are included under the popular definition of Eurasia, in spite of being separate from the massive landmass.
Physiographically, Eurasia is a single continent. The concepts of Europe and Asia as distinct continents date back to antiquity and their borders are geologically arbitrary. In ancient times the Black Sea and the Sea of Marmara, along with their associated straits, were seen as separating the continents, but today the Ural and Caucasus ranges are more seen as the main delimiters between the two. Eurasia is connected to Africa at the Suez Canal, and Eurasia is sometimes combined with Africa as the supercontinent Afro-Eurasia. Due to the vast landmass and differences in latitude, Eurasia exhibits all types of climate under the Köppen classification, including the harshest types of hot and cold temperatures, high and low precipitation and various types of ecosystems.
Eurasia formed 375 to 325 million years ago with the merging of Siberia (once a separate continent), Kazakhstania, and Baltica, which was joined to Laurentia, now North America, to form Euramerica. Chinese cratons collided with Siberia's southern coast.
Eurasia has been the host of many ancient civilizations, including those based in Mesopotamia, the Indus Valley and China. In the Axial Age (mid-first millennium BC), a continuous belt of civilizations stretched through the Eurasian subtropical zone from the Atlantic to the Pacific. This belt became the mainstream of world history for two millennia.
Originally, “Eurasia” is a geographical notion: in this sense, it is simply the biggest continent; the combined landmass of Europe and Asia. However, geopolitically, the word has several different meanings, reflecting the specific geopolitical interests of each nation. “Eurasia” is one of the most important geopolitical concepts; as Zbigniew Brzezinski observed:
“... how America "manages" Eurasia is critical. A power that dominates “Eurasia” would control two of the world’s three most advanced and economically productive regions. A mere glance at the map also suggests that control “Eurasia” would almost automatically entail Africa’s subordination, rendering the Western Hemisphere and Oceania geopolitically peripheral to the world’s central continent. About 75 per cent of the world’s people live in “Eurasia”, and most of the world’s physical wealth is there as well, both in its enterprises and underneath its soil. “Eurasia” accounts for about three-fourths of the world’s known energy resources.”
At the moment one of the most prominent projects of the European Union (EU) is the Russia - EU Four Common Spaces Initiative. A political and economic union of former Soviet states named the Eurasian Economic Union was established in 2015, similar in concept to the EU.
The Russian concept of “Eurasia” corresponded initially more or less to the land area of Imperial Russia in 1914, including parts of Eastern Europe. One of Russia's main geopolitical interests lies in ever closer integration with those countries that it considers part of “Eurasia.”
Every two years since 1996 a meeting of most Asian and European countries is organised as the Asia-Europe Meeting (ASEM).
In ancient times, the Greeks classified Europe (derived from the mythological Phoenician princess Europa) and Asia (derived from Asia, a woman in Greek mythology) as separate "lands". Where to draw the dividing line between the two regions is still a matter of discussion. Especially whether the Kuma-Manych Depression or the Caucasus Mountains form the southeast boundary is disputed, since Mount Elbrus would be part of Europe in the latter case, making it (and not Mont Blanc) Europe's highest mountain. Most accepted is probably the boundary as defined by Philip Johan von Strahlenberg in the 18th century. He defined the dividing line along the Aegean Sea, Dardanelles, Sea of Marmara, Bosporus, Black Sea, Kuma–Manych Depression, Caspian Sea, Ural River, and Ural Mountains.
Located primarily in the eastern and northern hemispheres, Eurasia is considered a supercontinent, part of the supercontinent of Afro-Eurasia or simply a continent in its own right. In plate tectonics, the Eurasian Plate includes Europe and most of Asia but not the Indian subcontinent, the Arabian Peninsula or the area of the Russian Far East east of the Chersky Range.
Eurasia is also sometimes used in geopolitics to refer to organizations of or affairs concerning the post-Soviet states, in particular, Russia, the Central Asian republics, and the Transcaucasian republics. A prominent example of this usage is in the name of the Eurasian Economic Community, the organization including Kazakhstan, Russia, and some of their neighbors, and headquartered in Moscow, Russia, and Astana, the capital of Kazakhstan.
The word "Eurasia" is often used in Kazakhstan to describe its location. Numerous Kazakh institutions have the term in their names, like the L. N. Gumilev Eurasian National University (Kazakh: Л. Н. Гумилёв атындағы Еуразия Ұлттық университеті; Russian: Евразийский Национальный университет имени Л. Н. Гумилёва) (Lev Gumilev's Eurasianism ideas having been popularized in Kazakhstan by Olzhas Suleimenov), the Eurasian Media Forum, the Eurasian Cultural Foundation (Russian: Евразийский фонд культуры), the Eurasian Development Bank (Russian: Евразийский банк развития), and the Eurasian Bank. In 2007 Kazakhstan's President, Nursultan Nazarbayev, proposed building a "Eurasia Canal" to connect the Caspian Sea and the Black Sea via Russia's Kuma-Manych Depression in order to provide Kazakhstan and other Caspian-basin countries with a more efficient path to the ocean than the existing Volga-Don Canal. This usage is comparable to how Americans use "Western Hemisphere" to describe concepts and organizations dealing with the Americas (e.g., Council on Hemispheric Affairs, Western Hemisphere Institute for Security Cooperation).