[4] More recently, the 18,000 km (11,000 mi) coastline has been used extensively for export-oriented trade, causing the coastal provinces to become the leading economic center.

The exact land area is sometimes challenged by border disputes, most notably about Taiwan, Aksai Chin, the Trans-Karakoram Tract, and South Tibet.

[5] It is diverse with snow-capped mountains, deep river valleys, broad basins, high plateaus, rolling plains, terraced hills, sandy dunes with many other geographic features and other landforms present in myriad variations.

The Ming-era walls run over 2,000 km (1,200 mi) east to west from Shanhaiguan on the Bohai coast to the Hexi Corridor in Gansu.

The Loess Plateau is bound to the east by the Luliang Mountain of Shanxi, which has a narrow basin running north to south along the Fen River.

In the north, the plateau is hemmed in by the Kunlun Mountains, which extends eastward from the intersection of the Pamirs, Karakorum and Tian Shan.

Flowing from its source in the Qingzang highlands, the Yellow River courses toward the sea through the North China Plain, the historic center of Chinese expansion and influence.

Han Chinese people have farmed the rich alluvial soils since ancient times, constructing the Grand Canal for north–south transport during the Imperial Era.

China has substantial mineral reserves and is the world's largest producer of antimony, natural graphite, tungsten, and zinc.

Other major minerals are aluminum, bauxite, coal, crude petroleum, diamonds, gold, iron ore, lead, magnetite, manganese, mercury, molybdenum, natural gas, phosphate rock, tin, uranium, and vanadium.

With comparatively little land planted to permanent crops, intensive agricultural techniques are used to reap harvests that are sufficient to feed the world's largest population and still have surplus for export.

Some overlap exists between the two regions because of natural dispersal and migration, and deer or antelope, bears, wolves, pigs, and rodents are found in all of the diverse climatic and geological environments.

The far-south of present-day China, the northern parts of today's Vietnam, and the Tarim Basin were first reached and durably subdued by the Han dynasty's armies.

Manchuria became strongly integrated into the Chinese empire during the late Qing dynasty, while the west side of the Changbai Mountains, formerly the home of Korean tribes, thus also entered China.

[8] A substantial number of Buddhists live in the southwestern Tibetan region of the country which borders Nepal, Bangladesh, and Bhutan and most notably India, the birthplace of Buddhism.

The Islamic population, consisting mostly of Hui and Uighur Muslims, is concentrated in the northwestern Xinjiang region of the country which shares borders with Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, India, and Russia.

[11] Other significant agricultural exports from China are potatoes, corn, tobacco, peanuts, tea, apples, cotton, pork, mutton, eggs, fish, and shrimp.

To the Han Chinese population, the territory of the country is defined by the regions of Tibet, inner Mongolia, Manchuria, and the Xinjiang Province which is the most western land of China.

[15] China's borders have more than 20,000 km (12,000 mi) of land frontier shared with nearly all the nations of mainland East Asia, and have been disputed at a number of points.

In a September 1986 speech in Vladivostok, the Soviet leader Mikhail S. Gorbachev offered the Chinese a more conciliatory position on Sino-Soviet border issues.

Eastward from Bhutan and north of the Brahmaputra River (Yarlung Zangbo Jiang) lies a large area controlled and administered by India but claimed by the Chinese.

The area was demarcated by the British McMahon Line, drawn along the Himalayas in 1914 as the Sino-Indian border; India accepts and China rejects this boundary.

Both countries had various claims to disputed territories such as the South Tibetan region of Zangnan which is considered to be part of the Arunachal Pradesh state in India.

[15] On 13 January 2011, the parliament of Tajikistan voted to ratify a 1999 deal to cede 1,000 km2 (390 sq mi) of land in the remote Pamir Mountain range, which thoroughly resolved a century-long border dispute with China.

[18] Owing to tremendous differences in latitude, longitude, and altitude, the climate of China is extremely diverse, ranging from tropical in the far south to subarctic in the far north and alpine in the higher elevations of the Tibetan Plateau.

During the summer, the East Asian Monsoon carries warm and moist air from the south and delivers the vast majority of the annual precipitation in much of the country.

Only in some pockets of the Dzungaria region of Xinjiang is the conspicuous seasonal variation in precipitation that defines Chinese (and, to a large extent, East Asian) climate absent.

Seasonal patterns in sunshine vary considerably by region, but overall, the north and the Tibetan Plateau are sunnier than the south of the country.

Heavy deforestation with an estimated loss of one-fifth of agricultural land since 1949 to soil erosion and economic development is occurring with resulting desertification.

China has signed, but not ratified, the Kyoto Protocol (but is not yet required to reduce its carbon emission under the agreement, as is India) and the Nuclear Test Ban treaty.