North America

North America is the third-largest continent, occupying the northern part of the Western Hemisphere between the Arctic Ocean and the Panama isthmus, with an area of roughly 24.7 million square kilometres. It contains 23 sovereign states along with numerous dependent territories, from the Canadian Arctic and Greenland in the north to the Caribbean islands and Central America in the south. Its boundaries are partly conventional: geographers differ on whether the southern limit lies at the Darién watershed or at the Panama Canal, and the continent is treated as distinct from the broader concept of continents mainly by its shared geological and climatic history rather than by a single natural border. The continent's physical framework rests on ancient cratons such as Laurentia, which formed more than a billion years ago and still anchors its interior, while younger mountain belts such as the Rocky Mountains and the Appalachians record later episodes of plate tectonic activity. Its landscapes range from Arctic tundra and boreal forest to temperate prairies, deserts and tropical rainforests, which shape the distribution of biodiversity, ecosystems and human settlement.

North America matters for several reasons. Its geology provides much of the world's fossil fuel and mineral resources, and its interior grain belt feeds a large share of global food supply. Its climate and ice history have shaped global patterns of climate and sea level, and its rivers, lakes and coasts are central to continental water systems. Politically and economically, the continent's three largest economies are linked through extensive trade agreements, and its cultural life draws on Indigenous traditions, European colonial legacies, and African and Asian migration. The population, variously estimated at about 565 to 620 million depending on how territories are counted, is concentrated in a small number of large urban regions, while much of the northern land is sparsely inhabited.

This entry proceeds from the continent's definition and naming, through its geological foundations, tectonic history, landforms, drainage, climate and ecological zones, to its human geography. It then covers pre-Columbian and colonial history, political organization, economy and infrastructure, culture and language, and environmental change, ending with the history of mapping and the open questions that remain in the study of the continent.

地理范围、边界与命名

North America occupies the northern part of the Western Hemisphere. Its mainland is bounded by the Arctic Ocean to the north, the North Atlantic to the east, and the North Pacific to the west. In the broad definition used in most atlases, the continent also includes the island of Greenland and the Caribbean archipelago, with its southern limit set at the Isthmus of Panama. Greenland is geologically part of the North American plate, but it is politically a constituent country of the Kingdom of Denmark, so the continental definition and the political one do not coincide.

The southern boundary is the point where the continent is most often disputed. The most common demarcation in atlases and reference works follows the watershed of the Darién Mountains along the Colombia–Panama border, where the isthmus meets South America. This line runs through the Darién Gap, a roadless rainforest and swamp region roughly 100 km long that interrupts the Pan-American Highway. Because the line lies within Panama's territory, Panama as a whole is counted as part of North America and specifically as part of Central America. A less common view places the boundary at the Panama Canal, which crosses the isthmus farther north. Under that convention, the eastern part of Panama, including Darién Province, would fall on the South American side. The choice therefore determines how Panama's territory is assigned, not only where a line is drawn on a map.

Several regional labels are used alongside the continental name, and they overlap in ways that often confuse readers. "Anglo America" generally refers to Canada and the United States, reflecting their shared English-speaking colonial and institutional heritage. "Latin America" usually includes Mexico, Central America, the Caribbean, and the whole of South America, grouping regions where Romance languages became dominant during colonization. Because the Caribbean is treated as a separate cultural and political zone in some contexts, its placement within either North America or Latin America depends on the classification in use. "The Americas" refers to North and South America together. None of these terms has an official geographic status, and their meanings shift between academic disciplines, governments, and journalism.

The relationship between the Americas and the larger landmasses also depends on convention. North and South America are joined by the Isthmus of Panama, but they are separated from Europe, Africa, and Asia by the Atlantic and Pacific oceans. Some schemes treat Eurasia and Africa as a single supercontinent, sometimes called Afro-Eurasia, in which case the Americas form its western portion. This grouping rests on geological history and on the long-standing "Old World" and "New World" distinction, rather than on a natural break in the crust. Tectonically, the boundary between the two continents is also not identical to the isthmus. The Caribbean plate lies between the North American and South American plates, so the plate boundary runs through the Caribbean region rather than along the Darién line, a fact that some geologists use to argue for a different definition of the southern limit.

These choices are not merely academic. Atlases, statistical agencies, and international organizations apply different conventions, which can lead to different totals for the area and population of the continent, and to different classifications for Panama and the Caribbean states. Readers comparing sources should check which convention each one follows.

Precambrian Geological Foundations: Laurentia

Laurentia (North American Craton) is the Precambrian core of North America, also known as the North American craton, and forms the ancient basement of the continental interior. It is a craton—a region of ancient, stable Continental Crust that has undergone little large-scale deformation since the Proterozoic. Its original extent also included Greenland and the Hebridean terrane of northwestern Scotland, which separated from it when the North Atlantic opened. The name derives from the St. Lawrence River, which flows across it. Laurentia is considered one of Earth's largest and possibly oldest cratons, with some rocks approaching four billion years in age.

The ages of rocks within Laurentia vary considerably. Most of its northern crust formed about 1.8 billion years ago or earlier, whereas its southern crust formed mainly between about 1.8 and 1.3 billion years ago, followed by substantial additional accretion during the Mesoproterozoic. Within this framework, the oldest core consists of Archean blocks, generally between 2.5 and 4 billion years old. Among these, the Superior craton is one of Earth's best-preserved and largest Archean cratons. It covers extensive areas of central Canada and extends beneath the northern Great Plains. Its Archean rocks formed about 2.9–2.7 billion years ago. These ancient blocks remained relatively stable throughout subsequent geological history, forming the structural framework of Laurentia.

The main assembly of Laurentia took place during the Paleoproterozoic. About 2.0–1.8 billion years ago, several Archean continental blocks, including the Superior craton, the Hearne–Rae blocks, and the Wyoming craton, collided in a vast episode of Orogeny known as the Trans-Hudson orogeny. The final collision in this orogenic belt occurred about 1.83–1.80 billion years ago, and its scale is thought to have been comparable to that of the present-day Himalayan–Karakoram–Tibetan orogenic belt. The process began with rifting that separated the Superior craton from the other continental blocks; the intervening ocean basin then closed, bringing the blocks back together in collision. The thick crustal roots produced by the collision helped keep this region stable for a long time afterward. Over the next roughly 900 million years, Laurentia continued to grow through the accretion of island arcs and other younger crust. Its southeastern margin underwent the Grenville orogeny about one billion years ago, setting the stage for subsequent supercontinent assembly.

The Canadian Shield (Canadian Shield) is the portion of Laurentia exposed at the surface. It extends across eastern and central Canada and southward into the northern United States, forming a roughly horseshoe-shaped region stretching from the Lake Superior area north to the Arctic Archipelago. Because the overlying sedimentary layers had been eroded before the ice ages, the shield exposes extensive areas of ancient igneous and metamorphic rocks. During the last ice age, the Laurentide Ice Sheet covered the entire shield. Glaciers scraped away most loose material, leaving thin soils, abundant exposed bedrock, and numerous lakes. As a result, drainage is poor, and lakes and swamps are widespread. The shield's bedrock also hosts important mineral resources. Deposits of nickel, copper, gold, silver, and uranium are extensively mined here, with mining districts such as Sudbury located within the shield.

The bedrock structure of Laurentia has therefore played a fundamental role in shaping North America's landforms and the distribution of its resources. The ancient rocks of the northern shield determine the principal distribution of mineral deposits, while its glacially modified terrain influences the arrangement of rivers and lakes. To the south and west, Laurentia is covered by thicker layers of Phanerozoic sediments and adjoins terranes accreted later. These subsequent tectonic processes are discussed in other sections of this article.

板块构造演化与大陆形成史

Rodinia: assembly and breakup

The supercontinent Rodinia was assembled during the Grenville orogeny, a long series of collisions that lasted roughly from 1.3 to 1.0 billion years ago and joined cratonic blocks, including the core of Laurentia, into one landmass. Later rifting along Laurentia's western margin began to split the supercontinent apart at about 800 to 750 million years ago. The rifted edge then evolved into a passive margin, which set the stage for the later growth of the western mountain belts. Rodinia's breakup opened the ocean basins that would later close and reopen as the continents rearranged themselves through repeated cycles of plate tectonic motion.

Paleozoic drift and Laurussia

During the Paleozoic, Laurentia drifted northward and rotated while crossing low latitudes. The Iapetus Ocean, which had opened as Rodinia broke up, lay between Laurentia and the blocks that would later join it, and its closure during the Ordovician to Devonian drove the Taconic and Caledonian orogenies. The collisions that closed Iapetus welded Laurentia to Baltica and other fragments into the continent known as Laurussia (sometimes called Euramerica), a major step toward the assembly of Pangaea later in the Paleozoic. Many of the structures produced by these collisions are now buried or deeply eroded, and they are reconstructed mainly from rock records and paleomagnetic data.

Mesozoic–Cenozoic opening of the North Atlantic

The separation of Greenland from North America began much earlier than an 80-million-year date would suggest. Baffin Bay is the northwestern extension and terminus of the North Atlantic-Labrador Sea rift system that started forming 140 million years ago in the Early Cretaceous epoch. Rifting and breakup of these margins began during the Early Cretaceous (~125 Ma) and ended during the Late Cretaceous (~85 Ma) based on borehole data. Seafloor spreading in the Labrador Sea followed, beginning first in the south during the Late Cretaceous (~70-80 Ma), and then propagating to the north and ending in the Late Eocene (~40 Ma) when seafloor spreading ceased. Spreading in Baffin Bay started later, in the Paleocene. Separation from Europe came later still: a major change in spreading occurred at ~55 Ma when rifting began separating Greenland from Europe. The result was a sequence of linked rift basins and a gradual widening of the North Atlantic that continues today.

Cordilleran orogeny and the contrast between the Rockies and the Appalachians

The western mountains of North America formed along an active margin where oceanic plates subducted beneath the continent. Subduction of the Farallon plate and related processes built the Cordilleran belt, and the Laramide phase, roughly 80 to 55 million years ago, raised the Rocky Mountains far inland from the plate boundary, a deformation often attributed to unusually shallow subduction. The Rockies are therefore geologically young and are tied to a convergent-margin setting. The Appalachians, by contrast, are much older: they formed through Paleozoic collisions associated with the closure of the Iapetus Ocean and the later assembly of Pangaea. Long periods of erosion have reduced them to the low, rounded ridges seen today. The two ranges thus differ both in age and in the mechanisms that produced them, a contrast that is central to reconstructing the geological history of the continent.

Major Terrain and Landform Regions

Western Mountain Ranges, Plateaus, and Basins

The mountain ranges of western North America form part of the North American Cordillera; the Alaska Range belongs to the broader American Cordillera. This system forms a relatively continuous belt of highlands across Alaska, western Canada, the western United States, and northern Mexico, with the Rocky Mountains and Mexico’s Sierra Madre ranges forming its principal eastern and western framework. Between the mountain belts, enclosed or partly enclosed basins, such as the Great Basin, alternate with plateaus. Low precipitation in the southwest has produced characteristic desert basin landscapes.

Denali, North America’s highest peak, lies in the Alaska Range and rises to 20,310 feet (6,190 meters). The United States Geological Survey confirmed this elevation in a 2015 survey. Denali’s uplift is generally linked to events about 60 million years ago, when the Pacific Plate subducted beneath the North American Plate, forcing a mass of granite upward. Its vertical relief above the surrounding plateau is approximately 18,000 feet (5,500 meters), among the most pronounced on Earth. The formation of these mountains is directly related to compression at plate boundaries; further details can be found in [Plate Tectonics] and general theories of mountain formation.

The Central Great Plains

The Great Plains extend from western Canada to the southern United States. This physiographic province stretches from the Peace River plains in northwestern Canada to the Edwards Plateau in central Texas, spanning approximately 32 degrees of latitude. Its northern margin lies mainly in the Canadian provinces of Alberta, Saskatchewan, and Manitoba; contrary to a common misconception, it does not extend to the Arctic coast.

The Great Plains are gently sloping overall, but they are not uniformly flat. Much of the region is not especially level, and its overall gradient can also be misleading. Surface elevations gradually decrease from west to east: the western areas near the Rocky Mountains are higher, while elevations decline toward the eastern edge. The soils of the Great Plains are predominantly dark, fertile chernozems. In the southern and central prairie regions, they are characterized by dark A horizons rich in organic matter. Their parent material consists largely of glacial deposits, with glacial till predominating across the region. These conditions have helped earn the area its reputation as the “breadbasket of the world,” and it is one of North America’s principal grain-producing regions.

The East and Northeast: The Appalachians and the Canadian Shield

The Appalachian Mountains and the Canadian Shield are the two principal structural elements of the eastern landscape, although their origins and appearance differ markedly. The Appalachians are remnants of a Paleozoic mountain-building belt—an ancient and complex range whose present foundations are what remains after the erosion of mountains that were once far higher. They extend from northeastern Alabama to the Canadian border, a distance of nearly 2,400 kilometers, separating the Atlantic coast from the interior. The rock strata of this mountain system formed between 540 million and 300 million years ago. Its low, rolling ridges reflect differences in the erosion of softer and harder rock layers over long periods. East of the mountains, the Atlantic Coastal Plain and the Florida Peninsula are low, flat areas formed by more recent sediment deposition.

The Canadian Shield lies north of the Appalachians and the Great Lakes. It is the exposed portion of Laurentia and a classic example of a craton. It is North America’s principal area of exposed Precambrian rocks, which formed more than 542 million years ago. The shield’s surface is characterized by extremely thin soils and extensive exposures of bedrock. This landscape is largely a product of the last glacial period, when a thick Ice Sheet covered the shield and scraped away most of its loose material. Depressions carved by Glacier erosion later filled with water, leaving the shield with numerous lakes and relatively subdued relief. Similar ancient basement rocks also occur in Greenland, where most of the Greenland Shield is covered by an ice sheet.

Topographic Extremes

North America’s topographic extremes can be measured on several scales, from elevation to relative relief. Beyond Denali, Alaska’s Aleutian Islands and Greenland’s ice sheet exemplify volcanic island-arc and continental ice-sheet landscapes, respectively. The former lie near a plate boundary in the North Pacific, while the latter covers most of Greenland and is discussed in the Ice Sheet entry. Denali’s Indigenous name was officially restored in 2015. The mountain is known as “Denali” to the Koyukon people, and in that year its official name was changed from Mount McKinley back to Denali.

水系、湖泊与冰期遗迹

The Mississippi system is the main drainage network of North America's interior, and it is the drainage basin that matters most for the continent's interior plains. The Mississippi River is the largest drainage basin in the United States. Estimates of its size depend on where the boundary is drawn. One federal engineering source says the basin covers more than 1,245,000 square miles, includes all or parts of 31 states and two Canadian provinces, while a general reference gives a total of about 1,151,000 square miles, of which only about one percent is in Canada. The trunk stream starts at Lake Itasca in northern Minnesota, and along its course it receives the Missouri, the Ohio, the Arkansas and the Red. The Missouri is the longest U.S. river, though the Mississippi is the second-longest. The Ohio, by contrast, is a much shorter tributary, about 981 miles from Pittsburgh, Pennsylvania to Cairo, Illinois. The river system as a whole therefore links the Rockies, the Appalachians and the Great Plains into one drainage pattern.

The lakes of northern North America are largely a legacy of the most recent ice age. The Wisconsin glaciation was the most recent glacial period of the North American ice sheet complex, peaking more than 20,000 years ago. The ice sheet that did most of the work was the Laurentide, which covered the high latitudes of central and eastern North America. Its maximum extent came about 25,000–21,000 years ago, and its effects radically altered the geography north of the Ohio River, creating the Great Lakes. Ice in the lake region may have been roughly 1,000 metres thick, and possibly more than 9,000 ft (3,000 m) thick farther north. Yet the basins were not created by ice alone. The lakes formed by glacial erosion, but geological features that formed 300 million to 1.2 billion years ago predetermined the shapes of America's huge inland seas. Lake Superior illustrates this: it began life a billion years ago as a huge rift, a crack in the continental crust. Advancing ice lobes also tended to follow earlier drainage lines carved into weaker rock. Together the five lakes hold a very large share of the planet's surface fresh water, about 20% of Earth's liquid surface freshwater.

The retreat of the ice left a landscape of barriers, deposits and new water bodies. About 20,000 years ago the ice sheet began to melt. As the glacier receded northward, floods of meltwater filled the deep depressions it had carved and were trapped in place by the banks of moraines it left behind. The lakes did not appear all at once. At times, flooding caused all the lakes to merge into single larger lakes, such as Lake Algonquin, but as lake levels stabilized, the five modern lakes took shape. Glacial sediments are equally varied, consisting of silt, clay, sand, and gravel left behind after ice and water eroded the bedrock. The same process reorganized rivers across the continent. During the last glacial period, the Laurentide Ice Sheet blocked the Missouri River and created Glacial Lake Great Falls. When the ice retreated, the lake emptied catastrophically in a glacial lake outburst flood. Episodes like this show that the present drainage pattern, including the divides between the Gulf and Hudson Bay watersheds, is the product of ice-age events and not of uniform river erosion.

Groundwater and wetlands are the less visible parts of the same inherited landscape. Large aquifers in the Great Plains, most notably the High Plains (Ogallala) aquifer that lies beneath parts of eight states, supply irrigation water for much of the region's farmland, and in some areas withdrawals have outpaced natural recharge. Along the Atlantic and Gulf coasts, wetlands and estuaries filter sediment, absorb storm surge and serve as nursery habitat for fish and shellfish, which makes them sensitive to coastal development and rising sea levels. The connection between surface water and these coastal systems is also visible at sea. Nutrient runoff from the Mississippi basin feeds the hypoxic zone in the Gulf of Mexico, which reached a maximum of nearly 23,000 km² in 2017. This pattern is a direct example of eutrophication that begins far upstream, and it shows how the drainage system links inland farming to coastal ecology.

气候类型与区域差异

Latitudinal span and climate belts

North America extends from the ice-covered northern islands, beyond 80°N, to the Panama border near 7°N, so its climates range from polar to tropical. Polar and subarctic conditions dominate the Arctic archipelago, northern Canada and the interior of Alaska, where winters are long and severe and some subarctic districts record temperatures far below −40°C. Most of the United States and southern Canada lie in temperate latitudes, where summers are warm and winters cold, and the main contrasts come from elevation and distance from the sea. The Mexican lowlands, the Caribbean islands and Central America lie in the tropics, where temperatures stay high through the year and rainfall, rather than temperature, separates the seasons. The Köppen–Geiger scheme is the standard way to map these belts, and it can be applied to North America's latitudinal sequence from polar to tropical.

Continental and maritime contrasts

Climate on the continent is shaped by the balance between continental and maritime influences. Continental climates, with large annual temperature swings, hot summers and cold winters, prevail in the interior, usually north of about 40°N. The Rocky Mountains intercept moist air from the Pacific, so the region east of them has a drier, more continental regime than the coast to the west. Along the Pacific coast, the prevailing westerlies bring mild, wet winters and cool summers to the Pacific Northwest and British Columbia. Further south, between roughly 30°N and 45°N, California's coast has a Mediterranean pattern, with hot, dry summers and winter rain that falls mostly in storms from the Pacific. The Atlantic and Gulf of Mexico coasts receive warm, humid air masses from the south, which makes the summers of the southeastern United States and the Gulf coast muggy and rainy, and winters there are much milder than in the interior at the same latitude.

Extreme weather systems

Several large-scale systems produce the most damaging weather. Tropical cyclones form over the warm waters of the Gulf of Mexico, the Caribbean and the eastern Pacific, with the Atlantic season running from June to November. Their remnants can bring prolonged rain to inland areas, including central Mexico. In the central United States, the collision of warm, moist air from the Gulf with cool, dry air from the Rockies produces severe convective storms, including tornadoes and hail, mostly in spring and early summer. The El Niño–Southern Oscillation (ENSO) is the most important source of interannual variability. During El Niño winters, the subtropical jet tends to steer storms across the southern tier of the United States and California, while the Ohio Valley and parts of the Pacific Northwest often see drier conditions. Northern states are frequently milder than normal. Strong El Niño events also tend to suppress Atlantic hurricanes by increasing vertical wind shear, while favoring more storms in the eastern Pacific. La Niña produces the opposite pattern, with drier and hotter conditions in the Southwest and the southern Plains that can deepen drought. Because the effects vary from event to event, the strength of the signal depends on both the episode's intensity and local topography.

Mexico's monsoon and rainy season

Mexico has a distinct wet-dry rhythm rather than four temperate seasons. The North American monsoon is a seasonal shift in winds that draws moist air from the Gulf of Mexico and the eastern Pacific northward. Its core lies over the Sierra Madre Occidental in Sinaloa, Durango, Sonora and Chihuahua, and it typically runs from June to mid-September, sending storms into Arizona and New Mexico and occasionally farther north. In central and southern Mexico, the rainy season generally begins in May or June and lasts until October or November. Moist air is forced upward by the surrounding mountain ranges, producing afternoon thunderstorms, often brief and intense, that give the highland valleys of Mexico City and Guadalajara most of their annual rain. The timing of onset depends on latitude, elevation and local topography: the Pacific coast usually receives its first rains before the Yucatán Peninsula, and northern Baja California sees little monsoon influence, relying instead on winter frontal systems. Rainfall totals rise toward the south, and parts of the southern states receive more than 2,000 mm a year. Because the highlands depend on the wet season to recharge aquifers and fill reservoirs, the timing of the rains governs crop cycles and water supply through the dry season, while intense downpours also strain urban drainage systems in low-lying districts.

生物群区与植被

Polar tundra

Treeless tundra covers northern Canada and the ice-free margins of Greenland, where short summers, strong winds and continuous permafrost restrict plant growth. The vegetation is low, mostly mosses, lichens, sedges, grasses, dwarf willows and birches, and heath shrubs such as crowberry and Labrador tea. In summer the upper layer of ground thaws, which leaves many poorly drained surfaces with ponds and wet hollows. Cold temperatures slow decomposition, so tundra soils hold large stores of organic carbon. The southern edge of the tundra is the treeline, which follows the temperature of the warmest months rather than a sharp latitude.

Boreal forest

The boreal forest, known as taiga in Russian usage, runs across Canada and Alaska and forms one of the largest continuous forest belts on Earth. Its dominant trees include black spruce, white spruce, balsam fir, tamarack (a deciduous larch), trembling aspen, paper birch and jack pine. Cold, waterlogged soils favour the growth of peat in bogs and fens, and these peatlands are among the most important carbon stores in the wetland systems of the continent. Large wildfires periodically clear stands, and some species are fire-adapted. Jack pine and black spruce, for example, retain serotinous cones that open and release seeds after burning. Moose, caribou, lynx and many migratory birds depend on this biome, and its carbon storage and albedo make it significant for climate regulation.

Temperate grasslands and deciduous forests

The Great Plains of the central United States and southern Canada consist of grassland that changes with precipitation. In the east, tallgrass prairie of big bluestem, switchgrass and Indiangrass grows where rainfall is relatively high and fire was frequent. Further west, shortgrass prairie of blue grama and buffalo grass dominates a drier landscape. Moisture declines westward, and the boundary between grassland and forest is largely set by this gradient and by soil texture. Fire historically prevented woody plants from spreading into the grassland. The deep, fertile soils have led to conversion for agriculture, so only small fragments of native prairie remain. East of the plains, deciduous forests of oak, hickory, maple, beech and tulip tree dominate the Appalachian and Midwestern landscapes. Around the Great Lakes these hardwood stands mix with white pine and hemlock, forming a transition zone toward the boreal forest.

Deserts and Mediterranean-type shrublands

The southwestern deserts are structurally distinct. The Sonoran Desert, with saguaro cactus, palo verde and creosote bush, receives rain in both winter and summer, the latter linked to the North American monsoon. The Mojave Desert, home to Joshua trees, is drier and cooler, while the Chihuahuan Desert supports desert grasslands and succulents such as lechuguilla. The Great Basin, further north, is covered by sagebrush and salt-tolerant shrubs. Plants in these deserts rely on deep roots, small or succulent leaves and dormancy during drought. Coastal California has a Mediterranean climate with wet winters and dry summers, and its chaparral consists of dense evergreen, hard-leaved shrubs such as chamise, manzanita and ceanothus. Many chaparral species are fire-adapted, and fire frequency is high in this region.

Tropical and subtropical forests

Southern Mexico, Central America and the Caribbean contain the most structurally complex vegetation on the continent. Tropical rainforest occurs in wet lowlands, such as the Lacandon region of Chiapas and La Mosquitia on the Caribbean coast of Honduras and Nicaragua. Tropical dry forests lose much of their foliage during the dry season, while pine-oak and cloud forests occupy the highlands. Mangroves, chiefly red, black and white species, line sheltered coasts and estuaries, where their roots stabilize sediment and provide nursery habitat for fish and shellfish. Many of these forests contain high numbers of tree species per hectare, along with epiphytes and lianas. Because of this diversity and high endemism, the region is closely tied to the biodiversity hotspot of Mesoamerica and to the wider ecosystem networks of the Caribbean islands.

生物多样性、特有物种与入侵物种

Southern Mexico and Central America form one of the world's most important biodiversity hotspots. The isthmus's mix of ancient crystalline uplands, younger metamorphic mountain ranges, and active volcanoes helped the region develop its own species, and its figures for endemism are high. One regional profile estimates 24,000 species of vascular plants, of which approximately 5,000 (21%) are endemic. Another CEPF species summary gives a lower count, some 17,000 species of vascular plants, nearly 3,000 of which are endemic, so the totals vary with how the hotspot is delimited and which survey is used. Vertebrates show a similar pattern. Of the 521 mammal species, 210 (a remarkable 40%) are endemic. For reptiles and amphibians, more than 690 species are found here, nearly 35 percent of which are endemic, and over 350 of the more than 550 amphibian species are endemic.

The same mountains that generate this diversity also shape where species occur. The highlands and mountain chains along the hotspot's main north-south axis have promoted isolation and speciation, and because they often act as an impassable barrier, species composition differs considerably between the Pacific and Caribbean coasts. By contrast, the valleys and lowlands running parallel to the mountains have long served as natural corridors for animal and human migrations. The region is also a major bird route: it is a critical flyway for at least 225 migratory species, and three of the Western Hemisphere's four migratory bird routes converge in Mesoamerica.

The Caribbean islands show endemism of a different kind, driven by isolation. The relative isolation of the islands has given rise to many endemic forms, and the biodiversity that results is characterized by small populations, a narrow genetic base, reduced competitive abilities, limited dispersal opportunities and restricted distributions. All 200 native amphibian species in the Caribbean are endemic, many to single islands. Birds follow a similar pattern on a smaller scale: the hotspot supports 565 bird species, 26% of which are endemic to the region. Isolated offshore islands near Mexico have comparable cases; on Cozumel, for example, two threatened mammals, the Cozumel harvest mouse and the Cozumel raccoon, are confined to offshore islands. Because the Caribbean as a whole supports one of the highest numbers of globally threatened species of any hotspot in the world, its small populations face compounded risk.

Migratory birds link these regions to the rest of the continent. Banding research helped waterfowl managers map the major migration corridors followed by ducks and geese, which are known today as flyways. For management purposes, North America is divided into four flyways: the Atlantic, Mississippi, Central, and Pacific. These routes are shaped by terrain and resources, since these pathways are influenced by geography, climate, and the availability of food and shelter. The Mississippi route is built around the river's catchment, stretching from the boreal forests and prairie potholes of Canada through the heart of the continent to the Gulf Coast and beyond. Along the Atlantic coast, Red Knots travel from Tierra del Fuego to the Arctic and back each year, with Delaware Bay serving as a critical refueling stop. In arid western North America, the migratory system depends on wetlands fed by lakes and rivers: migratory pathways are structured around endorheic watersheds that support large saline and freshwater lakes, in addition to freshwater palustrine wetlands along lake peripheries and throughout surrounding riparian drainages. Because such stopover wetlands and river corridors are scattered and linked in sequence, the continuity of the wildlife corridor network affects whether migratory populations can complete their annual cycle.

Invasive species pose a particularly severe threat on islands, and the Caribbean is an example. Island biota are vulnerable because of the generally small populations of indigenous species, the evolutionary effects of isolation, and the release of introduced species from natural enemies. The most damaging invasive alien species on islands are typically terrestrial vertebrates, such as goats, feral cats, pigs and rats. These species are responsible for more than half of all animal extinctions on islands globally. A well-documented case is the small Indian mongoose, deliberately introduced to several islands between 1870 and 1900 to control rats (themselves exotic) and venomous snake populations. As predators, mongooses have been found to be the major cause of extinction of several species of skink lizards endemic to the West Indies. Since European arrival, the region has lost a large share of its vertebrate fauna: the Caribbean has experienced 10% of the world's bird extinctions, 38% of mammal extinctions, and over 65% of reptile extinctions, with more than two-thirds attributable to invasive species.

Management has shown that removing invasive predators and herbivores can reverse some of these losses. On Redonda Island in Antigua and Barbuda, following the removal of rats and feral goats, the island's vegetation quickly rebounded and breeding seabird populations increased. Similar results have been recorded elsewhere, with populations of seabirds and other sensitive species increasing dramatically after invasive species were eradicated from uninhabited or lightly populated islands around the world. Globally, invasive species have been identified as a major driver of extinction; invasive alien species have been a major factor in 60% of species extinctions worldwide, according to an IPBES assessment cited by Caribbean conservation bodies. On the mainland, the pressures are less documented in detail, but the same logic of small, isolated, or disturbed populations applies to the species that are most sensitive to change.

人口分布与人口结构

Total population and definitional differences

Estimates of North America's population differ mainly because analysts disagree about which dependent territories to include and which reference year to use. Recent 2026 figures cluster around 620 to 625 million people. One estimate puts the 2026 total at about 623.7 million, and another gives a population of 624,965,770 people as of 1 January 2026. Older figures are still in circulation: a 2021 estimate placed the population at over 592 million people, or about 7.5% of humanity. The continent's political structure adds to the ambiguity, since it includes 23 sovereign states alongside a similar number of non-sovereign territories.

Uneven spatial distribution

The United States is the demographic core of the continent. Its population was 341,784,857 on July 1, 2025, according to the U.S. Census Bureau. Mexico follows with roughly 132 million people, and Canada has about 40 million residents. Greenland, by contrast, has a population of under 60,000 people. Settlement is strongly coastal: large metropolitan areas line the coasts and the Great Lakes, and where they grow close enough to overlap they form megalopolises. The Boston-Washington corridor is the classic example, while the Los Angeles–San Diego corridor on the West Coast is another. Interior areas are far less dense; the Great Plains and Rocky Mountain regions have much lower population density and smaller, more dispersed cities. Mexico displays a different pattern, in which one city dominates the entire system, and Mexico City's metropolitan area alone holds over 21 million people.

Urbanization

North America is among the most urbanized regions on Earth. The degree of urbanization is over four-fifths of the population residing in urban areas, and a World Bank series based on UN data gives 82.55 as of 2020 for the share of urban population. Definitions vary across countries, so such figures should be read with care; some countries count settlements with 100 houses or more as urban, while others only include the capital of a country or provincial capitals. Large agglomerations are also prominent. In 2023, New York ranked among the world's largest urban areas with 21.4 million inhabitants. Urban growth has taken a suburban form as well. Sprawl, defined as the expansion of human settlements away from central cities and into low-density, car-dependent communities, has shaped metropolitan growth, and counterurbanization, the shift in populations from urban centers to suburban and rural settlements, has been prevalent in North America since the end of World War II. Toronto illustrates the pattern: its city proper has about 2.8 million residents, while its metropolitan area exceeds 5.5 million. Infrastructure, housing and environmental pressures follow from this concentration, and they are particularly acute in the largest metropolitan areas.

Migration and population structure

Natural increase remains positive across the region; in 2025, births exceeded deaths by more than five million people. Yet the balance is shifting toward migration. The continent's largest economy is aging and slowing. In the United States, the total fertility rate was 1.58 children born per woman (2025), and people aged 65 and over made up 18.4% of the population. The U.S. population growth rate of 0.5% in 2025 was tied to a decline in net international migration, which means fewer arrivals from abroad drove the slowdown. Immigrants made up 15.2% (2024) of the U.S. population.

Migration has also shaped the ethnic and cultural composition of the continent. Migrants from Europe, Africa, Asia and Latin America have all contributed to contemporary populations, and the mix differs sharply between countries, for example between the United States, Canada, Mexico and the Caribbean states. Population growth rates, age structures and the share of foreign-born residents therefore vary considerably from one country to another, and these differences are central to debates about labor supply, pensions and regional planning in the coming decades.

前哥伦布时期的原住民社会

Most researchers link the first human arrival in the Americas to Beringia, the region around the Bering Strait that connected northeastern Asia and western Alaska when lower sea levels during glacial periods exposed the seabed. The date of that crossing is still debated. Conflicting evidence has led to wide disagreement about the timing and number of migrations across Beringia, which may have occurred as early as 28,000 years ago or as late as 11,000 years ago. The vast majority of radiocarbon dates from secure archaeological contexts in the Americas favor migration dates in the latter half of this range. Because the ice sheets of the Last Glacial Maximum sealed off the continental interior, a Pacific Coast route was the more likely pathway for dispersals from Beringia into North America, and boats may have carried early groups down the coast. Once south of the ice, populations spread fairly rapidly throughout North and South America. The Bluefish Caves in Yukon, which hold some of the oldest dated human remains in North America, are one of the sites that support an early presence in the north.

In Mesoamerica, the agricultural base was maize, which domesticated by 5000 BCE, formed the basis of their diet. The Olmec, who built urban centers of San Lorenzo and La Venta, used these centers mainly for ceremonial purposes, while most people lived in villages. Their successors inherited a range of traits. The Zapotec developed a calendar and a logosyllabic system of writing that used a separate glyph to represent each of the syllables of the language. This writing system is thought to be one of the first writing systems of Mesoamerica. The Maya, whose earliest settlements date to around 1800 B.C., were agricultural, growing crops such as corn (maize), beans, squash and cassava. Their classic period peaked around the sixth century A.D., and most of the great stone cities of the Maya were abandoned by A.D. 900, a decline whose causes are still studied.

Mesoamerican calendars were built on the rhythm of the agricultural year. The Maya ran a 260-day sacred count, and one interpretation holds that the Maya understood the 260-day calendar to be a representation of the life cycle of maize. The 260-day count was combined with a solar year of 365 days, and 52 years will pass until the three cycles line up again. The Aztec, or Mexica, used the same structure: the 365-day xiuhpōhualli is considered to be the agricultural calendar, since it is based on the sun, while the 260-day tōnalpōhualli served ritual purposes. The Aztec empire, centered on Tenochtitlan, flourished from the 14th to the 16th century.

North of the Mexican highlands, subsistence strategies differed sharply. Arctic peoples, including the ancestors of today's Inuit, developed sea-mammal hunting and adapted to snow and ice; Pacific Northwest coastal groups relied on salmon and other marine resources to support large, settled communities; and Plains societies combined bison hunting with, in some river valleys, small-scale farming. These patterns produced varied social organizations, from kin-based bands to ranked villages. On the island of Newfoundland, the sequence of occupation was long: the earliest peoples were the Maritime Archaic, followed by the Groswater and Dorset cultures, as well as the ancestors of the now culturally extinct Beothuk.

The Norse presence on the continent was brief and localized. Around 1000 CE, Norse voyagers from Greenland and Iceland established a camp at the northern tip of Newfoundland, now known as L'Anse aux Meadows. Situated at the tip of the Great Northern Peninsula of the island of Newfoundland, this exceptional archaeological site consists of eight timber-framed turf structures built in the same style as those found in Norse Greenland and Iceland from the same period. Radiocarbon work places the occupation around AD 990–1050. Archaeologists suggest that the settlement served as an exploratory base and winter camp, with industrial activity for iron production and woodworking, likely used for ship repair. The lack of burials and agricultural features suggests the site was occupied only for a short period. The site was excavated by Helge and Anne Stine Ingstad after its discovery in 1960, and it is now a UNESCO World Heritage Site. Its remains match the Vinland accounts in the Icelandic sagas, and L'Anse aux Meadows was inhabited by Indigenous peoples at least 4,000 years before the arrival of the Norse.

欧洲殖民、奴隶贸易与独立运动

From the late fifteenth century, Spain, France, England and, in South America, Portugal established colonies across the Americas. Spain conquered the Aztec Empire in 1519–1521 and built the viceroyalty of New Spain, with administrative centres in Mexico City and Lima, and extended its rule over the Caribbean and Central America. France developed New France along the St. Lawrence River and later the Mississippi valley, while England founded Atlantic seaboard colonies from Virginia in 1607 onward. Epidemic diseases brought by Europeans caused a demographic collapse among Indigenous peoples, and forced labour systems, land seizure and missionary campaigns reshaped economies, languages and religious life. Many Indigenous communities survived but lost much of their territory and political autonomy, and the colonial societies that replaced them were organised around European legal and religious institutions.

The colonies depended heavily on enslaved African labour. Between 1500 and 1866, about 12.5 million enslaved Africans were transported to the Americas, and roughly 1.8 million of them died during the Middle Passage. Most were sent to Brazil and the Caribbean, where they worked on sugar plantations and in mines, while a smaller share went to North America, where they were concentrated in tobacco, rice and, later, cotton production in the southern colonies and states. Portuguese merchants dominated the trade for much of its history, and British slave traders later became the largest carriers. The system created large populations of African descent in the Caribbean, Brazil and the American South, and it also established racial hierarchies in law and social life that persisted long after abolition. Its effects on demography and social institutions remain central to the study of the region's population structure.

Independence movements in the late eighteenth and early nineteenth centuries produced a set of separate states rather than a single political unit. The United States declared independence in 1776 and drafted its federal constitution in 1787–1788. Haiti declared its independence in 1804 after a revolution led by formerly enslaved people, making it the first state in Latin America to end colonial rule and slavery together. Mexico's independence war began with the Grito de Dolores in 1810 and ended in 1821, and the Central American provinces of the former Spanish captaincy general declared independence in the same year, before their short-lived federation fragmented into separate republics. Canada's path was different: the British North America Act of 1867 created the Dominion of Canada from several British colonies, and additional provinces joined in the following decades, so that the country moved toward full sovereignty gradually within the British Empire. These transitions are part of the broader pattern of decolonization in the Western Hemisphere, although their timing and outcomes differed widely among the states involved.

Territorial expansion in the nineteenth century fixed the continent's modern borders. The United States acquired the Louisiana territory from France in 1803, and its westward expansion displaced many Indigenous nations, a process accelerated by the Indian Removal Act of 1830. After the annexation of Texas in 1845, the Mexican–American War of 1846–1848 ended with the Treaty of Guadalupe Hidalgo, under which Mexico ceded roughly half of its territory, and the Gadsden Purchase of 1854 completed the southern boundary of the contiguous United States. Canada's expansion relied on infrastructure as much as diplomacy: the Canadian Pacific Railway, completed in 1885, linked the Atlantic and Pacific coasts and helped bind western territories such as Manitoba and British Columbia to the federation. Together these developments produced the borders, federal arrangements and national capitals that define the present political map, with the boundaries between Mexico and the United States and between Canada and the United States becoming the most consequential for later trade and migration. The sovereignty claims and federal structures that emerged from this period still shape the region's politics.

政治地理与国家构成

Political organization in North America is uneven. The mainland is divided among sovereign states, while several islands and the large territory of Greenland remain under European or US control.

主权国家与属地

North America contains 23 sovereign states, and the continent also includes a number of dependent territories. The largest is Greenland. It has been Danish territory for centuries and part of the Kingdom of Denmark since 1953. Caribbean dependencies are tied mainly to European states: the Netherlands administers Aruba, Curaçao and Sint Maarten, the United Kingdom holds territories such as Anguilla, the Cayman Islands and the Turks and Caicos Islands, and France governs Guadeloupe and Martinique. Puerto Rico and the US Virgin Islands are US territories. Some small island disputes remain, for example over Machias Seal Island between Canada and the United States, and over Navassa Island, which the United States administers and Haiti also claims.

格陵兰的自治与主权

Greenland's status is the most legally complex question in the region. It gained home rule in 1979, becoming self-governing in its internal affairs, while remaining part of the Kingdom of Denmark. The current framework dates from 2009. Greenland, an autonomous part of the Kingdom of Denmark, has a unique status under the Self-Government Act, which came into effect on June 21, 2009. The arrangement followed a referendum in which 75.5% of Greenlandic voters approved the new autonomy arrangement in November 2008.

The Act treats Greenlanders as a people entitled to self-determination. It also sets out a route to independence: any decision regarding Greenland's independence must be taken by the people of Greenland, and the Greenlandic and Danish governments would then negotiate an agreement on the path to independence. Denmark keeps control over several core areas. Self-government authorities may take over most fields of responsibility, but the constitution, foreign affairs, defence and security policy, the Supreme Court, nationality, and exchange rates and monetary policy are excluded. Greenland's legislature has 31 members elected for four-year terms, and the territory sends two representatives to the Danish parliament.

Recent US interest in Greenland has brought these questions into international legal debate. Scholars have asked whether self-determination could ever permit a transfer of territory to a third state, and how that would interact with the principle of territorial integrity.

联邦制与地方行政

The three largest states of the mainland use federal structures, though their arrangements differ. The United States has 50 states, each with its own constitution, legislature and courts, and the Tenth Amendment reserves to the states the powers not delegated to Washington. Canada has ten provinces and three territories. Its provinces control natural resources, education and health care, while the federal government manages defence, currency and criminal law. Mexico has 31 states and a federal district, Mexico City. Its federal system has long coexisted with a strong presidency and a centralized tax system.

In all three countries, the division of powers is an ongoing political issue. Debates often focus on fiscal transfers between central and regional governments, control of energy and mineral revenues, and the balance between federal authority over security and immigration and provincial or state authority over local policy. These questions appear in court rulings, budget negotiations and, in Canada, recurring disputes over resource development and interprovincial pipelines.

区域合作机制

Regional cooperation is organized around several frameworks. The most economically significant is the United States–Mexico–Canada Agreement, which was signed in 2018 and came into effect in 2020. It replaced NAFTA. The agreement contains a scheduled review: the Free Trade Commission must now conduct a joint review every year for the remainder of the Agreement's 16-year term after the United States declined to extend it in July 2026. The three partners still operate under the existing text, and the extension can be approved at any time.

In the Caribbean, the Caribbean Community (CARICOM) has operated as a regional grouping since 1973. It coordinates trade, foreign policy and development among mainly English-speaking island states, and it also maintains relations with Latin American and European partners. In Central America, the Central American Integration System (SICA) provides the institutional framework. It was established on December 13, 1991, and Belize and the Dominican Republic subsequently joined as full members in 2000 and 2013, respectively. Some sources describe the Dominican Republic as an associate member instead, so its status varies across references.

These arrangements overlap. Some Caribbean states belong to both CARICOM and SICA, and both groups interact with the broader Western Hemisphere through the Organization of American States. Their agreements complement, rather than replace, the customs union and free-trade structures among the larger economies. The trade relationships between the United States, Canada and Mexico remain the largest single economic bloc on the continent.

边界与海洋主权

Sovereignty disputes on land have mostly been settled, but maritime and island boundaries continue to matter. Exclusive economic zones extend far into the Atlantic, Pacific and Arctic, and their boundaries affect fisheries, seabed minerals and shipping routes. The Arctic has attracted particular attention because melting sea ice opens new routes and resources. Canada, Denmark (on behalf of Greenland), and the United States all assert claims in the Arctic Ocean, and international law, particularly the United Nations Convention on the Law of the Sea, provides the framework for resolving them. The 2022 agreement dividing Hans Island between Canada and Denmark showed that even small features can be settled through negotiation.

经济结构与自然资源

农业

The Great Plains of the central United States and southern Canada form one of the world's largest grain and oilseed production zones. Wheat is the region's leading crop. Although China grows more wheat, the United States and Canada together supply more than half of the world's wheat exports . Canola has pushed cultivation northward across Canada's prairies because the crop performs well in short northern seasons with long summer days . Canada also ships large volumes of canola and sunflower oil to the United States, Europe and Asia . Canada's oilseed output is forecast to fall 4% in 2026–27, to about 27.55 million tonnes, as a larger share of seed is crushed domestically . Since the 1930s, governments in both countries have managed surpluses that would otherwise depress prices, and they have pursued overseas markets for grain exports .

能源与矿产

Canada's oil sands in Alberta are the largest single component of its petroleum resources. Roughly 159 billion barrels of proven reserves are in the oil sands, about 98% of the national total, which places Canada fourth in the world . Output reached 3.5 million barrels per day in 2024 , close to 60% of Canadian crude production . Extraction methods depend on how deep the bitumen lies . Royalties from the sector, at $17 billion in fiscal 2024–25, were the largest single source of government revenue . The oil sands are developed mainly by private firms, with investment from Canada, the United States, Europe and Asia . An EIA country analysis based on 2014 data found that nearly all of Canada's crude exports went to US refineries .

The United States holds extensive shale oil and gas formations, and its hydrocarbon output has grown considerably in recent years. Coal, natural gas and a range of metallic minerals are also produced across the continent. These resources give North America a significant position in global energy trade, while raising questions about emissions and the transition to renewable energy.

制造业与服务业

The automotive sector is the most tightly integrated part of the region's industrial base. Intra-bloc auto trade reached about $280 billion a year, a 38% rise since 2021 . Around 70% of this trade consists of capital or intermediate goods, which indicates how interdependent the three economies have become . Components often cross borders several times before a vehicle is finished . In 2024, Canada and Mexico together supplied nearly half of US vehicle and parts imports and took roughly three-quarters of US auto exports .

Services account for the largest share of economic output in the United States and Canada, with finance, health care, professional services and information industries playing central roles. Manufacturing is concentrated in the United States, Canada and Mexico, where electronics and machinery chains extend across the three countries.

贸易一体化

The United States–Mexico–Canada Agreement governs about $1.6 trillion in annual cross-border commerce . It keeps zero tariffs for most goods traded among the three countries while setting detailed rules on what counts as North American production . Passenger vehicles must now contain 75% regional value content to qualify, up from 62.5% under NAFTA , and steel and aluminum used in vehicles must be 70% North American by value . The US International Trade Commission has found that these rules support US parts and materials producers, but they also raise costs for vehicle manufacturers and shift some imports toward non-member countries . A 2022 dispute panel ruled against the United States on one aspect of the auto rules of origin . The 2026 review of the agreement has become a focal point, and analysts are weighing whether added uncertainty could erode the investment and supply-chain resilience the agreement was built to support .

交通、城市与基础设施

Overland travel across North America relies on a few long corridors. The Pan-American Highway was conceived in a 1937 agreement among a group of American states that included Canada, the United States and Mexico, with the aim of linking Alaska with South America. Its length depends on which branches are counted. The main trunk from Prudhoe Bay, Alaska, is most often put at about 30,000 kilometres (19,000 miles), but totals quoted by different sources range from roughly 16,000 to over 30,000 miles. The route is not continuous. The Darién Gap, a roughly 100-kilometre stretch of roadless rainforest on the Colombia–Panama border, has never been bridged by a road, so travellers usually ship their vehicles around it. Because it is the only land connection between the two continents, the gap has also become a major migration route, which makes it a point of concern for border management as well as for road planning.

Waterborne transport is organized around three systems. The Great Lakes–St. Lawrence Seaway System connects the freshwater lakes to the Atlantic. Binational work completed the waterway and opened it to deep-draft navigation in 1959. In 2022 about 135.7 million metric tons of cargo moved through its ports, valued at more than US$26 billion. Most of this tonnage is bulk cargo, such as grain, iron ore, coal, potash and petroleum products, and it supports a large number of jobs in the region. The Mississippi River system functions as an inland artery for barges carrying grain, coal and petrochemicals, linking the Gulf of Mexico to the interior. The Panama Canal provides a shortcut between the Atlantic and Pacific oceans and handles a significant share of cargo moving between the coasts of the United States and East Asia and Latin America.

Urban networks are dense and unevenly distributed. Greater Mexico City is the largest metropolitan area on the continent, although estimates differ with the counting method: about 21.4 million people in the 2020 count, roughly 22.8 million in other recent estimates, and more than 25 million in some projections for 2026. The capital proper holds only a little over 7% of Mexico's population, but about one in five Mexicans lives in the wider metropolitan area. The city sits on the former bed of Lake Texcoco, which shapes its drainage, subsidence and water problems. New York, Los Angeles, Chicago, Toronto and Monterrey follow, and sixteen of the world's hundred largest urban areas are located in North America. These metropolitan regions concentrate jobs, ports and airports, and in turn generate heavy commuting, freight congestion and sprawl. Public transit investment, roads and freight corridors are therefore constant planning issues, and urban growth has often outpaced the capacity of existing networks.

Energy infrastructure is integrated across borders to a greater degree than most other systems. Oil and natural gas pipelines carry fuel between producing regions in Canada and the United States and into the energy markets of the United States' southern neighbour, and cross-border transmission lines allow electricity to be traded between the three countries. The continent's power system is not a single network: it is divided into several largely separate regional grids, and Mexico's system is connected to the north only through a limited number of ties. This structure has made grid reliability a central concern, particularly during extreme weather, when a failure in one region can quickly affect others. At the same time, the growth of wind and solar generation, along with large hydroelectric resources in Canada, is pushing planners to expand transmission and storage so that renewable output can be moved and balanced across regions.

Languages, Religion, and Cultural Traditions

North America's linguistic landscape has been shaped by colonial history, immigration, and the continuity of Indigenous communities. The English Language predominates in the United States and most of Canada. Canada is officially bilingual in English and French at the federal level, with French speakers concentrated in Quebec. Spanish is Mexico's national language, while dozens of Indigenous languages are also recognized as national languages. Nahuatl and the Mayan languages still have substantial numbers of speakers in some regions. In the southwestern United States, Indigenous languages such as Navajo also retain sizable speaker communities. The Caribbean has a more complex linguistic landscape: English, Spanish, French, and Dutch serve as official languages in various island nations and territories, while creole languages originating in the colonial period are also spoken throughout the region. Research on Language often regards these creoles as products of contact and blending.

Haiti is a characteristic example. Haitian Creole (Kreyòl) shares official status with French. Much of its vocabulary is borrowed from French, but its grammatical structure differs markedly. The language developed through communication between French colonists and enslaved Africans and had acquired distinct linguistic features by the early eighteenth century. Haiti's constitution recognized its official status in 1987; before then, it had long been regarded as a language of lower standing than French. Louisiana Creole and Michif—a language blending French and Cree, spoken in some communities in Canada's Maritime provinces—are similar phenomena on the North American mainland. Creole language formation is directly linked to forced migration within colonial economies, making these languages important case studies in language contact.

In religion, Christianity is North America's dominant tradition, although its composition varies significantly by region. Mexico's 2020 census found that approximately 77.7% of the population identified as Catholic, and Catholics have also long accounted for a large share of the population in most Central American countries. In recent decades, however, the overall proportion of Catholics has declined, Protestant and evangelical churches have grown rapidly, and the share of people with no religious affiliation has risen. A 2026 Pew Research Center survey of six major Latin American countries found that Catholics accounted for between 46% and 67% of adults, with declines in all six countries over the preceding decade. Beyond Christianity, communities practicing Judaism are concentrated mainly in major cities such as New York, Toronto, and Montreal, while Islam has expanded with increasing immigration. Traditional Indigenous beliefs also endure, and many communities have developed religious practices that combine Indigenous rituals with Catholic worship. Diversity in Religion is particularly evident in cities, while the blending of traditional beliefs and Christianity remains widespread in rural areas and Indigenous communities.

In literature and the arts, North America has developed two major traditions. English-language literature, centered on the United States and Canada, encompasses a range of strands, from realist novels to contemporary narratives reflecting diverse perspectives; Canadian writer Margaret Atwood is one notable representative. Spanish-language literature has developed distinctive styles in Mexico, the Caribbean, and Central America. Mexican poet Octavio Paz received the Nobel Prize in Literature, while the Mexican muralist movement, represented by figures such as Diego Rivera and José Clemente Orozco, transformed public art in the twentieth century. In music, American jazz and blues, Jamaican reggae, Mexican mariachi, and Caribbean merengue and salsa have all achieved widespread influence beyond their places of origin. Indigenous oral narratives, songs, and crafts continue to inform contemporary creative work and are intertwined with questions of Culture, identity, and land rights.

In cultural heritage, numerous Indigenous sites and colonial-era remains have been inscribed on UNESCO's World Heritage List. Mexico has the largest number of World Heritage sites in the Americas, with sources reporting between 35 and 36, depending on the date of the count. These include the remains of the Maya city of Chichén Itzá, the combined heritage site of the Historic Centre of Mexico City and Xochimilco, and the Zapotec site of Monte Albán. Franciscan monasteries and missions built in the sixteenth century reflect religious and architectural exchanges during the early colonial period. Mexican mariachi music and the Day of the Dead (Día de Muertos) have also been inscribed on the United Nations' intangible cultural heritage lists. Mesa Verde and the Chaco cultural sites in the United States, along with Head-Smashed-In Buffalo Jump in Alberta, Canada, are likewise important sites for conservation and tourism. Questions of who has the authority to interpret this heritage and how it should be presented often prompt discussion between Indigenous communities and the institutions that manage these sites.

环境变化、气候影响与资源压力

Low-lying land along the Atlantic seaboard, the Gulf of Mexico and the Caribbean islands is among the most exposed to rising seas. A higher baseline sea level lets storm surges from tropical cyclones reach farther inland, and it accelerates the erosion of beaches, wetlands and barrier islands. Because many of these coasts hold dense cities, ports and farmland, even modest increases in water level raise the stakes for flood defence and land-use planning.

The Arctic side of the continent is changing faster than most regions. Temperatures in the Arctic are already warming two to four times faster than the global average, and in Alaska annual mean temperatures have risen about 0.4°C per decade since the late 1970s, about twice as fast as the global average. The consequences reach into the ground itself. Thawing permafrost has begun to release stored carbon: the frozen soils of Alaska, western Canada and Siberia hold twice as much carbon as currently resides in the atmosphere. Researchers have found that the region has become a net contributor to warming in recent decades, largely because of methane, a gas that traps far more heat per molecule than carbon dioxide.climate-change Thaw also damages built environments. The ground becomes increasingly unsteady as permafrost soils thaw, which is causing damage to buildings and roads. Along northern shorelines, thawing permafrost is causing erosion, which threatens Arctic coastal communities. Canada's northern territories illustrate the scale of the problem: these areas have warmed at a rate two to three times greater than the global average in the past fifty years. Visible signs are emerging as well; in Alaska's Brooks Range, rivers are increasingly common, the result of thawing permafrost, and their orange colour comes from iron released by thawing ground.

Drought and wildfire are the second major pressure, concentrated in the West and Southwest. Research shows that changes in climate create warmer, drier conditions, leading to longer and more active fire seasons. Attribution studies have estimated that warming accounted for more than half of the decline in fuel moisture in western U.S. forests between 1979 and 2015, and that burned area roughly doubled over 1984–2015. Drought has also spread widely: in 2024, 48 of 50 US states faced drought conditions, the highest proportion ever recorded in the country. Analyses by Climate Central cited in one data review report that the average western fire season now runs 105 days longer than before. The 2020–2022 seasons were particularly severe, with all three years far surpassing the average of 1.2 million acres burned since 2016. These trends bear directly on water supply, forest health and the safety of expanding suburbs bordering wildland areas.

The Great Lakes show how nutrient pollution can undo decades of progress. In 2011, Lake Erie experienced the largest harmful algal bloom in its recorded history, with a peak intensity over three times greater than any previously observed bloom. Phosphorus is the main driver. Of the agricultural sources, about 70 percent of the nutrients are from commercial fertilizer application and 30 percent from animal manure. Earlier, the lake had recovered after phosphorus controls in the 1970s and 1980s, including limits on wastewater discharge and bans on phosphate detergents. Blooms nevertheless returned in the 2000s from new sources. Researchers also point to invasive quagga mussels and zebra mussels as a possible factor in the resurgence. In response, Ohio, Michigan and Ontario committed in 2015 to cutting phosphorus inputs by 40% by 2025, but data consistently shows that it is unlikely the 2025 goal will be met. Because the lakes straddle the Canada–U.S. border and the rivers that feed them cross state and provincial lines, the management of algal blooms depends on the binational cooperation that the Great Lakes Water Quality Agreement was designed to provide.

研究历史、测绘与未解问题

European mapping of the continent accelerated after 1492, and the naming of the New World is itself a cartographic story. The earliest known use of the name America dates to April 25, 1507, when Martin Waldseemüller applied it to what is now South America on his world map. The map also treated the Americas as a separate landmass. Its compilers drew on the Italian cartographer Amerigo Vespucci's survey of the Brazilian coast in 1501–2, which had convinced him that these lands formed a new continent. The northern part of the continent acquired its own name only later. In 1538, Gerardus Mercator placed both names on one of his maps, and these two names remain in use today. In the centuries that followed, coastal surveys, overland exploration and the mapping of interior rivers and lakes gradually fixed the continent's outline and internal structure, a process traced in cartography and exploration history.

The modern geological picture of North America rests on plate tectonics, a framework that gained general acceptance in the twentieth century. Once continents were understood as moving plates, researchers could place the evolution of the ancient core, Laurentia, within global plate reconstructions. These reconstructions are repeatedly revised as new isotopic dating, paleomagnetic records and seismic imaging become available, particularly for the Archean and Proterozoic assembly of the cratonic core, where the sequence of collisions remains only partly resolved.

Some boundary questions are settled by convention rather than by nature, and they depend on the purpose of a given study. The southern limit is the most consequential. Most geographers place it along the Darién divide on the Colombia–Panama frontier, which keeps Panama within Central America. A minority view places it along the Panama Canal, which would assign Panama differently. Greenland raises a related problem: it lies on the North American side of the North Atlantic rift system, yet it is politically part of the Kingdom of Denmark and is often grouped with Europe in statistical and political contexts. The position of the Caribbean islands is handled in a similar way, since their inclusion in North America, the Caribbean or South America varies with the criteria used. These choices affect population totals, regional statistics and the sovereignty questions attached to each territory.

Among the most debated questions in the continent's recent past is the disappearance of its large mammals at the end of the Ice Age. Extinctions in North America were concentrated around 13,800–11,400 years before present, coincident with the onset of the Younger Dryas cooling period and the emergence of the Clovis culture. Overall losses in North America reached 72% of megafaunal species, the highest proportion on any continent apart from Australia and South America. Researchers have generally divided into camps that emphasize human overhunting, climate change, or some combination of the two. Analyses of population signals in the archaeological record have not produced a single answer. One study concluded that in three cases extinctions appear linked to hunting, in five others they are consistent with the ecological effects of climate change, and in one case both appear responsible. The role of megafauna in ecosystem structure, which is closely tied to this debate, is itself an active research area.

The timing and route of human arrival in the Americas also remain open. People were widespread across the Americas by at least 13,000 calibrated years BP, but their population sizes were small, and how strongly hunting affected megafauna populations remains unresolved. This uncertainty underlies the so-called "one-two punch" hypothesis, in which climate change and human impacts combined to drive the losses. Continued work in archaeology and paleoecology is still refining that picture. Finally, the long-term consequences of rapid environmental change in the Arctic, where warming outpaces the global average, are being studied through models and field records, but their full trajectory is not yet established.

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120. The Oil Sands October 2025capp.ca
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131. The Great Lakes-St. Lawrence Seaway Navigation System: Options for Growthcongress.gov
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133. Great Lakes-St. Lawrence Seaway System - Port Authorityduluthport.com
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150. Record-setting algal bloom in Lake Erie caused by agricultural and meteorological trends consistent with expected future conditionspnas.org
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