Land, also known as dry land, ground, or earth, is the solid terrestrial surface of
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
not submerged by the
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
or another
body of water
A body of water or waterbody is any significant accumulation of water on the surface of Earth or another planet. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as ponds, wetlands, or more rare ...
. It makes up 29.2% of Earth's surface and includes all
continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
s and
island
An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...
s. Earth's land surface is almost entirely covered by
regolith
Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestria ...
, a layer of
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wale ...
,
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
, and
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...
s that forms the outer part of the
crust. Land plays an important role in Earth's
climate system
Earth's climate system is a complex system with five interacting components: the Atmosphere of Earth, atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere ( ...
, being involved in the
carbon cycle
The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycl ...
,
nitrogen cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, atmospheric, terrestrial ecosystem, terrestrial, and marine ecosystems. The conversion of nitrogen can ...
, and
water cycle
The water cycle (or hydrologic cycle or hydrological cycle) is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth across different reservoirs. The mass of water on Earth remains fai ...
. One-third of land is covered in
trees
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only p ...
, another third is used for
agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
, and one-tenth is covered in permanent snow and
glacier
A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...
s. The remainder consists of
desert
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...
,
savannah
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...
, and
prairie
Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...
.
Land
terrain
Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...
varies greatly, consisting of mountains, deserts, plains, plateaus, glaciers, and other
landform
A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement ...
s. In physical geology, the land is divided into two major categories:
Mountain range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...
s and relatively flat interiors called
craton
A craton ( , , or ; from "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and rifting of contine ...
s. Both form over millions of years through
plate tectonics
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
.
Stream
A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...
s – a major part of Earth's water cycle – shape the
landscape
A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal.''New Oxford American Dictionary''. A landscape includes th ...
, carve rocks, transport sediments, and replenish groundwater. At high elevations or
latitude
In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...
s,
snow
Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water througho ...
is compacted and recrystallized over hundreds or thousands of years to form glaciers, which can be so heavy that they warp the Earth's crust. About 30 percent of land has a dry climate, due to losing more water through evaporation than it gains from
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
. Since warm air rises, this generates winds, though
Earth's rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own Rotation around a fixed axis, axis, as well as changes in the orientation (geometry), orientation of the rotation axis in space. Earth rotates eastward, in progra ...
and uneven sun distribution also play a part.
Land is commonly defined as the solid, dry surface of Earth. It can also refer to the collective
natural resources
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. ...
that the land holds, including
rivers
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
,
lakes
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...
, and the
biosphere
The biosphere (), also called the ecosphere (), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to mat ...
. Human manipulation of the land, including
agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
and
architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...
, can also be considered part of land. Land is formed from the
continental crust
Continental crust is the layer of igneous, metamorphic, and sedimentary rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as '' continental shelves''. This layer is sometimes called '' si ...
, the layer of rock on which
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
.
groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...
, and human and animal activity sits.
Though modern terrestrial
plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
s and
animal
Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...
s evolved from aquatic creatures, Earth's
first cellular life likely originated on land. Survival on land relies on
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...
from rivers, streams, lakes, and glaciers, which constitute only three percent of the water on Earth. The vast majority of human activity throughout history has occurred in
habitable land areas supporting agriculture and various
natural resource
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. ...
s. In recent decades, scientists and policymakers have emphasized the need to
manage land and its biosphere more sustainably, through measures such as restoring
degraded soil, preserving
biodiversity
Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...
, protecting
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
, and addressing
climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
.
Definition
Land is often defined as the solid, dry surface of Earth.
The word ''land'' may also collectively refer the collective
natural resources
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. ...
of Earth,
including its
land cover,
river
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...
s, shallow
lake
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...
s, its
biosphere
The biosphere (), also called the ecosphere (), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to mat ...
, the lowest layer of the atmosphere (
troposphere
The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
),
groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...
reserves, and the physical results of human activity on land, such as
architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...
and agriculture.
The boundary between land and sea is called the
shoreline
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
.
Etymology
The word ''land'' is derived from
Old English
Old English ( or , or ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-S ...
, from the
Proto-Germanic
Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the linguistic reconstruction, reconstructed proto-language of the Germanic languages, Germanic branch of the Indo-European languages.
Proto-Germanic eventually developed from ...
word , "untilled land", and then the
Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. No direct record of Proto-Indo-European exists; its proposed features have been derived by linguistic reconstruction from documented Indo-Euro ...
, especially in northern regions that were home to languages like
Proto-Celtic
Proto-Celtic, or Common Celtic, is the hypothetical ancestral proto-language of all known Celtic languages, and a descendant of Proto-Indo-European. It is not attested in writing but has been partly Linguistic reconstruction, reconstructed throu ...
and
Proto-Slavic
Proto-Slavic (abbreviated PSl., PS.; also called Common Slavic or Common Slavonic) is the unattested, reconstructed proto-language of all Slavic languages. It represents Slavic speech approximately from the 2nd millennium BC through the 6th ...
. Examples include
Old Irish
Old Irish, also called Old Gaelic (, Ogham, Ogham script: ᚌᚑᚔᚇᚓᚂᚉ; ; ; or ), is the oldest form of the Goidelic languages, Goidelic/Gaelic language for which there are extensive written texts. It was used from 600 to 900. The ...
''land'', "land, plot, church building" and
Old Irish
Old Irish, also called Old Gaelic (, Ogham, Ogham script: ᚌᚑᚔᚇᚓᚂᚉ; ; ; or ), is the oldest form of the Goidelic languages, Goidelic/Gaelic language for which there are extensive written texts. It was used from 600 to 900. The ...
''ithlann'', "threshing floor", and
Old East Slavic
Old East Slavic (traditionally also Old Russian) was a language (or a group of dialects) used by the East Slavs from the 7th or 8th century to the 13th or 14th century, until it diverged into the Russian language, Russian and Ruthenian language ...
''ljadina'' "wasteland, weeds".
A
country
A country is a distinct part of the world, such as a state, nation, or other political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, state with limited recognition, constituent country, ...
or
nation
A nation is a type of social organization where a collective Identity (social science), identity, a national identity, has emerged from a combination of shared features across a given population, such as language, history, ethnicity, culture, t ...
may be referred to as the
motherland
A homeland is a place where a national or ethnic identity has formed. The definition can also mean simply one's country of birth. When used as a proper noun, the Homeland, as well as its equivalents in other languages, often has ethnic natio ...
,
fatherland
A homeland is a place where a national or ethnic identity has formed. The definition can also mean simply one's country of birth. When used as a proper noun, the Homeland, as well as its equivalents in other languages, often has ethnic nation ...
, or
homeland
A homeland is a place where a national or ethnic identity has formed. The definition can also mean simply one's country of birth. When used as a proper noun, the Homeland, as well as its equivalents in other languages, often has ethnic natio ...
of its people.
Many countries and other places have names incorporating the suffix
-land The suffix -land, which can be found in the names of several countries or country subdivisions, indicates a toponymy - a land. The word derived from the Old English ''land'', meaning "ground, soil", and "definite portion of the earth's surface, home ...
(e.g.
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
,
Greenland
Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...
, and
New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
). The equivalent suffix ''
-stan
-stan ( Persian: ستان )(Sanskrit: ''sthān'' or ''sthānam)'' is a Persian suffix that has the meaning of "a place abounding in" or "place where anything abounds" as a suffix. It is widely used by Iranian languages (mainly Persian) and ...
'' from
Indo-Iranian, ultimately derived from the
Proto-Indo-Iranian
Proto-Indo-Iranian, also called Proto-Indo-Iranic or Proto-Aryan, is the reconstructed proto-language of the Indo-Iranian branch of Indo-European. Its speakers, the hypothetical Proto-Indo-Iranians, are assumed to have lived in the late 3rd ...
,
is also present in many country and location names, such as
Pakistan
Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...
,
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran borde ...
, and others throughout
Central Asia
Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...
. The suffix is also used more generally, as in
Persian
Persian may refer to:
* People and things from Iran, historically called ''Persia'' in the English language
** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples
** Persian language, an Iranian language of the ...
() "place of sand, desert", () "place of flowers, garden", () "graveyard, cemetery", and ''
Hindustân'' () "land of the
Indo people".
Physical science
The study of land and its history in general is called
geography
Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...
.
Mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...
is the study of minerals, and
petrology
Petrology () is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous ...
is the study of rocks.
Soil science
Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, soil classification, classification and Soil survey, mapping; Soil physics, physical, Soil chemistry, chemical, Soil biology, biologica ...
is the study of soils, encompassing the sub-disciplines of
pedology
Pedology (from Greek: πέδον, ''pedon'', "soil"; and λόγος, ''logos'', "study") is a discipline within soil science which focuses on understanding and characterizing soil formation, evolution, and the theoretical frameworks for modelin ...
, which focuses on soil formation, and
edaphology
Edaphology (from Greek , ''edaphos'' 'ground' + , ''-logia'') is concerned with the influence of soils on living beings, particularly plants.
It is one of two main divisions of soil science, the other being pedology. Edaphology includes the stud ...
, which focuses on the relationship between soil and life.
Formation

The earliest material found in the Solar System is dated to (billion years ago);
therefore, Earth itself must have been formed by
accretion around this time. The
formation and evolution of the Solar System
There is evidence that the formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while ...
bodies occurred in tandem with the Sun. In theory, a
solar nebula
There is evidence that the formation of the Solar System began about 4.6 bya, billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, whil ...
partitions a volume out of a
molecular cloud
A molecular cloud—sometimes called a stellar nursery if star formation is occurring within—is a type of interstellar cloud of which the density and size permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, ...
by gravitational collapse, which begins to spin and flatten into a
circumstellar disc
A Circumstellar disc (or circumstellar disk) is a torus, pancake or ring-shaped accretion disk of matter composed of gas, dust, planetesimals, asteroids, or collision fragments in orbit around a star. Around the youngest stars, they are the rese ...
, out of which the planets then grow (in tandem with the star). A nebula contains gas, ice grains and
dust
Dust is made of particle size, fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian processes, aeolian process), Types of volcan ...
(including
primordial nuclide
In geochemistry, geophysics and nuclear physics, primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed. Primordial nuclides were present in the ...
s). In the
nebular hypothesis
The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting t ...
,
planetesimal
Planetesimals () are solid objects thought to exist in protoplanetary disks and debris disks. Believed to have formed in the Solar System about 4.6 billion years ago, they aid study of its formation.
Formation
A widely accepted theory of pla ...
s begin to form as
particulate
Particulate matter (PM) or particulates are microscopic particles of solid or liquid matter suspended in the air. An ''aerosol'' is a mixture of particulates and air, as opposed to the particulate matter alone, though it is sometimes define ...
matter accumulates by
cohesive clumping and then by gravity. The primordial Earth's assembly took 10–.
By , the primordial Earth had formed.
Earth's atmosphere and oceans were formed by
volcanic
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often fo ...
activity and
outgassing
Outgassing (sometimes called offgassing, particularly when in reference to indoor air quality) is the release of a gas that was dissolved, trapped, frozen, or absorbed in some material. Outgassing can include sublimation and evaporation (whic ...
that included
water vapour
Water vapor, water vapour, or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor ...
. The
origin of the world's oceans was condensation augmented by water and ice delivered by
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
s,
protoplanet
A protoplanet is a large planetary embryo that originated within a protoplanetary disk and has undergone internal melting to produce a differentiated interior. Protoplanets are thought to form out of kilometer-sized planetesimals that gravitatio ...
s, and
comet
A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...
s.
In
this model, atmospheric "
greenhouse gas
Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
es" kept the oceans from freezing while the newly formed Sun was only at 70%
luminosity
Luminosity is an absolute measure of radiated electromagnetic radiation, electromagnetic energy per unit time, and is synonymous with the radiant power emitted by a light-emitting object. In astronomy, luminosity is the total amount of electroma ...
.
By , the
Earth's magnetic field
Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from structure of Earth, Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from ...
was established, which helped prevent the atmosphere from being stripped away by the
solar wind
The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...
.
The atmosphere and oceans of the Earth continuously shape the land by eroding and transporting solids on the surface.
Earth's crust formed when the molten outer layer of Planet Earth cooled to
form a solid mass as the accumulated water vapour began to act in the atmosphere. Once land became capable of supporting life, biodiversity evolved over hundreds of millions of years, expanding continually except when punctuated by mass extinctions.
The two models
that explain land mass propose either a steady growth to the present-day forms
or, more likely, a rapid growth
early in Earth history
followed by a long-term steady continental area.
Continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
s are formed by
plate tectonics
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
, a process ultimately driven by the continuous loss of heat from the Earth's interior. On
time scales
Time scale may refer to:
*Time standard, a specification of either the rate at which time passes, points in time, or both
*A duration or quantity of time:
** Orders of magnitude (time) as a power of 10 in seconds;
**A specific unit of time
A u ...
lasting hundreds of millions of years, the
supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...
s have formed and broken apart three times. Roughly (million years ago), one of the earliest known supercontinents,
Rodinia
Rodinia (from the Russian родина, ''rodina'', meaning "motherland, birthplace") was a Mesoproterozoic and Neoproterozoic supercontinent that assembled 1.26–0.90 billion years ago (Ga) and broke up 750–633 million years ago (Ma). wer ...
, began to break apart. The continents later recombined to form
Pannotia
Pannotia (from Greek: ''wikt:pan-, pan-'', "all", ''wikt:νότος, -nótos'', "south"; meaning "all southern land"), also known as the Vendian supercontinent, Greater Gondwana, and the Pan-African supercontinent, was a relatively short-lived Neo ...
, 600–, then finally
Pangaea
Pangaea or Pangea ( ) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous period approximately 335 mi ...
, which also broke apart .
Landmasses
A continuous area of land surrounded by an ocean is called a landmass. Although it is most often written as one word to distinguish it from the usage "land mass"—the measure of land area—it may also be written as two words. There are four major continuous landmasses on Earth:
Africa-Eurasia,
America (landmass),
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
, and
Australia (landmass), which are subdivided into
continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
s.
Up to seven geographical regions are commonly regarded as continents. Ordered from greatest to least land area, these continents are
Asia
Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...
,
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
,
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
,
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
,
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
,
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
, and
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
.
Terrain

Terrain refers to an area of land and its features. Terrain affects travel, mapmaking, ecosystems, and surface
water flow and distribution. Over a large area, it can influence climate and weather patterns. The terrain of a region largely determines its suitability for human settlement: flatter
alluvial plain
An alluvial plain is a plain (an essentially flat landform) created by the deposition of sediment over a long period by one or more rivers coming from highland regions, from which alluvial soil forms. A ''floodplain'' is part of the process, bei ...
s tend to have better farming soils than steeper, rockier uplands.
Elevation
The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
is defined as the vertical distance between an object and sea level, while
altitude
Altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum (geodesy), datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometr ...
is defined as the vertical distance from an object to Earth's surface. The elevation of Earth's land surface varies from the low point of at the
Dead Sea
The Dead Sea (; or ; ), also known by #Names, other names, is a landlocked salt lake bordered by Jordan to the east, the Israeli-occupied West Bank to the west and Israel to the southwest. It lies in the endorheic basin of the Jordan Rift Valle ...
, to a maximum altitude of at the top of Mount Everest. The mean height of land above sea level is about , with 98.9% of dry land situated above sea level.
Relief
Relief is a sculpture, sculptural method in which the sculpted pieces remain attached to a solid background of the same material. The term ''wikt:relief, relief'' is from the Latin verb , to raise (). To create a sculpture in relief is to give ...
refers to the difference in elevation within a landscape; for example, flat terrain would have "low relief", while terrain with a large elevation difference between the highest and lowest points would be deemed "high relief". Most land has relatively low relief. The change in elevation between two points of the terrain is called a slope or gradient. A
topographic map
In modern mapping, a topographic map or topographic sheet is a type of map characterized by large- scale detail and quantitative representation of relief features, usually using contour lines (connecting points of equal elevation), but histori ...
is a form of
terrain cartography
Terrain cartography or relief mapping is the depiction of the shape of the surface of the Earth on a map, using one or more of several techniques that have been developed. Terrain or relief is an essential aspect of physical geography, and as su ...
which depicts terrain in terms of its elevation, slope, and the orientation of its landforms. It has prominent
contour line
A contour line (also isoline, isopleth, isoquant or isarithm) of a Function of several real variables, function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a ...
s, which connect points of similar elevation, while perpendicular slope lines point in the direction of the steepest slope.
Hypsometric tints
Hypsometric tints (also called layer tinting, elevation tinting, elevation coloring, or hysometric coloring) are colors placed between contour lines to indicate elevation. These tints are shown as bands of color in a graduated scheme or as a col ...
are colors placed between contour lines to indicate elevation relative to
sea level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
.
A difference between uplands, or
highland
Highlands or uplands are areas of high elevation such as a mountainous region, elevated mountainous plateau or high hills. Generally, ''upland'' refers to a range of hills, typically from up to , while ''highland'' is usually reserved for range ...
s, and lowlands is drawn in several
earth science
Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...
fields. In river ecology, "
upland" rivers are fast-moving and colder than "lowland" rivers, encouraging different species of fish and other aquatic wildlife to live in these habitats. For example, nutrients are more present in slow-moving lowland rivers, encouraging different species of
macrophytes to grow there. The term "upland" is also used in wetland ecology, where "upland" plants indicate an area that is not a wetland. In addition, the term
moorland
Moorland or moor is a type of Habitat (ecology), habitat found in upland (geology), upland areas in temperate grasslands, savannas, and shrublands and the biomes of montane grasslands and shrublands, characterised by low-growing vegetation on So ...
refers to upland
shrubland
Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...
biomes with acidic soils, while
heathland
A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...
s are lowland shrublands with acidic soils.
Geomorphology
Geomorphology refers to the study of the natural processes that shape land's surface, creating landforms.
Erosion and tectonics
The interaction between erosion and tectonics has been a topic of debate since the early 1990s. While the tectonic effects on surface processes such as erosion have long been recognized (for example, river formation as a result of tectonic uplift ...
,
volcanic eruptions
A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior h ...
,
flooding
A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant concern in agriculture, civi ...
,
weathering
Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...
,
glaciation
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...
, the growth of
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...
s, and meteorite impacts are among the processes that constantly reshape Earth's surface over
geological time
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronolo ...
.
Erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...
transports one part of land to another via natural processes, such as
wind
Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...
, water,
ice
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...
, and
gravity
In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...
. In contrast, weathering wears away rock and other solid land without transporting the land somewhere else.
Natural erosional processes usually take a long time to cause noticeable changes in the landscape—for example, the
Grand Canyon
The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a mile ().
The canyon and adjacent rim are contained within Grand Canyon Nati ...
was created over the past 70 million years by the
Colorado River
The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...
,
which scientists estimate continues to erode the canyon at a rate of every 200 years. However, humans have caused erosion to be 10–40 times faster than normal, causing half the
topsoil
Topsoil is the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.
Description
Topsoil is composed of mineral particles and organic mat ...
of the surface of Earth's land to be lost within the past 150 years.
Plate tectonics
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
refers to the theory that Earth's lithosphere is divided into "tectonic plates" that move over the mantle.
This results in
continental drift
Continental drift is a highly supported scientific theory, originating in the early 20th century, that Earth's continents move or drift relative to each other over geologic time. The theory of continental drift has since been validated and inc ...
, with continents moving relative to each other. The scientist
Alfred Wegener
Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
During his lifetime he was primarily known for his achievements in meteorology and ...
first hypothesized the theory of continental drift in 1912. More researchers developed his idea throughout the 20th century into the now widely accepted theory of plate tectonics.
Several key characteristics define the modern understanding of plate tectonics. The place where two tectonic plates meet is called a
plate boundary
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
, with different geological phenomena occurring across different kinds of boundaries. For example, at
divergent plate boundaries,
seafloor spreading
Seafloor spreading, or seafloor spread, is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
History of study
Earlier theories by Alfred Wegener ...
is usually seen,
in contrast with the
subduction
Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...
zones of
convergent or
transform plate boundaries.
Earthquakes
An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they c ...
and
volcanic activity
Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a he ...
are common in all types of boundaries. Volcanic activity refers to any rupture in Earth's surface where
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...
escapes, therefore becoming
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...
.
The
Ring of Fire
The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a tectonic belt of volcanoes and earthquakes.
It is about long and up to about wide, and surrounds most of the Pa ...
, containing two-thirds of the world's volcanos, and over 70% of Earth's
seismological activity, comprises plate boundaries surrounding the
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...
.
Climate

Earth's land interacts with and influences its
climate
Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...
heavily, since the land's surface heats up and cools down faster than air or water.
Latitude
In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...
,
elevation
The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
,
topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps.
Topography is a field of geoscience and planetary sci ...
,
reflectivity
The reflectance of the surface of a material is its effectiveness in Reflection (physics), reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the respon ...
, and
land use
Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. The following categories are used for land use: fo ...
all have varying effects on climate. The latitude of the land will influence how much
solar radiation
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically p ...
reaches its surface. High latitudes receive less solar radiation than low latitudes.
The land's topography is important in creating and transforming airflow and
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
. Large landforms, such as mountain ranges, can divert wind energy and make
air parcels less dense and therefore able to hold less heat.
As air rises, this cooling effect causes
condensation
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor ...
and precipitation.
Different types of land cover will influence the land's
albedo
Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...
, a measure of the solar radiation that is reflected, rather than absorbed and transferred to Earth.
Vegetation
Vegetation is an assemblage of plants and the ground cover they provide. It is a general term, without specific reference to particular Taxon, taxa, life forms, structure, Spatial ecology, spatial extent, or any other specific Botany, botanic ...
has a relatively low albedo, meaning that vegetated surfaces are good absorbers of the sun's energy.
Forest
A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...
s have an albedo of 10–15 percent while
grassland
A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...
s have an albedo of 15–20 percent. In comparison, sandy
desert
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...
s have an albedo of 25–40 percent.
Land use by humans also plays a role in the regional and global climate. Densely populated cities are warmer and create
urban heat island
Urban areas usually experience the urban heat island (UHI) effect; that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds ar ...
s that have effects on the precipitation,
cloud cover
Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud c ...
, and temperature of the region.
Features
A landform is a natural or manmade land feature. Landforms together make up a given terrain, and their arrangement in the
landscape
A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal.''New Oxford American Dictionary''. A landscape includes th ...
is known as
topography
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps.
Topography is a field of geoscience and planetary sci ...
. Landforms include
hill
A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent as Mountain, mountains. Hills ...
s,
mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...
s,
canyon
A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency t ...
s, and
valley
A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...
s, as well as
shoreline
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
features such as
bay
A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a ''gulf'', ''sea'', ''sound'', or ''bight''. A ''cove'' is a small, ci ...
s,
capes, and
peninsula
A peninsula is a landform that extends from a mainland and is only connected to land on one side. Peninsulas exist on each continent. The largest peninsula in the world is the Arabian Peninsula.
Etymology
The word ''peninsula'' derives , . T ...
s.
Coasts and islands

The
shoreline
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
is the interface between the land and the
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
. It migrates each day as
tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables ...
s rise and fall and moves over long periods of time as
sea level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
s change. The shore extends from the low tide line to the highest elevation that can be reached by storm waves, and the
coast
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
stretches out inland until the point where ocean-related features are no longer found.
When land is in contact with bodies of water, it can be eroded. The weathering of a coastline may be impacted by the
tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables ...
s, caused by changes in gravitational forces on larger bodies of water.
Coasts are important zones in natural ecosystems, often home to a wide range of
biodiversity
Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...
. On land, they harbour important ecosystems such as freshwater or estuarine
wetland
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
s, which are important for bird populations and other terrestrial animals. In wave-protected areas they harbor
saltmarshes,
mangrove
A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...
s or
seagrasses
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
, all of which can provide
nursery habitat
In marine environments, a nursery habitat is a subset of all habitats where juveniles of a species occur, having a greater level of productivity per unit area than other juvenile habitats (Beck et al. 2001). Mangroves, salt marshes and seagrass ...
for finfish,
shellfish
Shellfish, in colloquial and fisheries usage, are exoskeleton-bearing Aquatic animal, aquatic invertebrates used as Human food, food, including various species of Mollusca, molluscs, crustaceans, and echinoderms. Although most kinds of shellfish ...
, and other aquatic species. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of
sessile animals (e.g.
mussel
Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...
s,
starfish
Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to ...
,
barnacle
Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...
s) and various kinds of
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
s. Along
tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
coasts with clear, nutrient-poor water,
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...
s can often be found between depths of .
According to a
United Nations
The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...
atlas, 44% of all people live within of the sea. Because of their importance in society and high concentration of population, the coast is important for major parts of the global food and economic system, and they provide many
ecosystem service
Ecosystem services are the various benefits that humans derive from ecosystems. The interconnected living and non-living components of the natural environment offer benefits such as pollination of crops, clean air and water, decomposition of wast ...
s to humankind. For example, important human activities happen in
port cities. Coastal
fisheries
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...
for commercial, recreational, and subsistence purposes, and
aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...
are major economic activities and provide jobs, livelihoods, and
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
for the majority of coastal human populations. Other coastal spaces like
beach
A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from Rock (geology), rock, such as sand, gravel, shingle beach, shingle, pebbles, etc., or biological s ...
es and
seaside resort
A seaside resort is a city, resort town, town, village, or hotel that serves as a Resort, vacation resort and is located on a coast. Sometimes the concept includes an aspect of an official accreditation based on the satisfaction of certain requi ...
s generate economic activity through
tourism
Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...
.
Marine coastal ecosystems can also provide protection against
sea level rise
The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...
and
tsunami
A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, ...
s. In many countries, the coastal
mangrove
A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...
is the primary source of wood for fuel (e.g. charcoal) and building materials. Coastal ecosystems have a much higher capacity for
carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. It plays a crucial role in Climate change mitigation, limiting climate change by reducing the amount of Carbon dioxide in Earth's atmosphere, carbon dioxide in the atmosphe ...
than many
terrestrial ecosystem
Terrestrial ecosystems are ecosystems that are found on land. Examples include tundra, taiga, temperate deciduous forest, tropical rain forest, grassland, deserts.
Terrestrial ecosystems differ from aquatic ecosystems by the predominant presen ...
s, and as such can play a critical role in the near future to help
mitigate climate change
Climate change mitigation (or decarbonisation) is action to limit the greenhouse gases in the atmosphere that cause climate change. Climate change mitigation actions include energy conservation, conserving energy and Fossil fuel phase-out, repl ...
effects by uptake of
atmospheric anthropogenic carbon dioxide.
A subcontinental area of land surrounded by water is an
island
An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...
,
and a chain of islands is an
archipelago
An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...
. The smaller the island, the larger the percentage of its land area will be adjacent to the water, and subsequently will be coast or beach. Islands can be formed by a variety of processes. The
Hawaiian islands
The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...
, for example, even though they are not near a plate boundary, formed from
isolated volcanic activity.
Atolls
An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most of ...
are ring-shaped islands made of
coral
Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...
, created when
subsidence
Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope mov ...
causes an island to sink beneath the ocean surface and leaves a ring of reefs around it.
Mountains and plateaus
Mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...
s are features that usually rise at least higher than the surrounding terrain. The
formation of mountain belts is called orogenesis, and results from
plate tectonics
Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...
.
For example, where a plate at a convergent plate boundary pushes one plate above the other, mountains could be formed by either collisional events, such that Earth's crust is pushed upwards,
or subductional events, where Earth's crust is pushed into the mantle, causing the crust to melt, rise due to its low density, and solidify into hardened rock, thickening the crust.
A
plateau
In geology and physical geography, a plateau (; ; : plateaus or plateaux), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. ...
, also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side, creating steep
cliff
In geography and geology, a cliff or rock face is an area of Rock (geology), rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. ...
s or
escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations.
Due to the similarity, the term '' scarp'' may mistakenly be incorrectly used inte ...
s.
Both volcanic activity such as the
upwelling
Upwelling is an physical oceanography, oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted sur ...
of magma and extrusion of lava, or erosion of mountains caused from water, glaciers, or aeolian processes, can create plateaus. Plateaus are classified according to their surrounding environment as intermontane, Foothills, piedmont, or
continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
al. A few plateaus may have a small flat top while others are wider. Buttes are smaller, with less extrusive and more intrusive igneous rock, while plateaus or highlands are the widest, and mesas are a general-sized plateau with horizontal bedrock strata.
Plains and valleys

Wide, flat areas of land are called plains, which cover more than one-third of Earth's land area.
When they occur as lowered areas between mountains, they can create
valley
A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...
s,
canyon
A canyon (; archaic British English spelling: ''cañon''), gorge or chasm, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency t ...
s or gorges, and ravines. A plateau can be thought of as an elevated plain. Plains are known to have fertile soils and be important for agriculture due to their flatness supporting grasses suitable for livestock and facilitating the harvest of crops. Floodplains provided agricultural land for some of the Cradle of civilization, earliest civilizations. Erosion is often a main driver for the creation of plains and valleys, with rift valleys being a noticeable exception. Fjords are glacial valleys that can be thousands of meters deep, opening out to the sea.
Caves and craters
Any natural void in the ground which can be entered by a human can be considered a cave. They have been important to humans as a place of Shelter (building), shelter since the dawn of humanity.
Craters are depressions in the ground, but unlike caves, they do not provide shelter or extend Subterranea (geography), underground. There are many kinds of craters, such as impact craters, volcanic calderas, and isostatic depressions. Karst processes can create both solution caves, the most frequent cave type, and craters, as seen in karst sinkholes.
Layers
The pedosphere is the outermost layer of Earth's continental surface and is composed of soil and subject to Pedogenesis, soil formation processes. Below it, the lithosphere encompasses both Earth's crust and the uppermost layer of the Earth's mantle, mantle. The lithosphere rests, or "floats", on top of the mantle below it via isostasy.
Above the solid ground, the
troposphere
The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
and humans' use of land can be considered layers of the land.
Land cover

Land cover refers to the material physically present on the land surface, for example, woody crops, herbaceous crops, barren land, and shrub-covered areas. Artificial surfaces (including cities) account for about a third of a percent of all land.
Land use refers to human allocation of land for various purposes, including farming, ranching, and recreation (e.g. national parks); worldwide, there are an estimated of cropland, and of pastureland.
Land cover change detection using remote sensing and geospatial data provides baseline information for assessing the climate change impacts on habitats and biodiversity, as well as natural resources, in the target areas. Land cover change detection and mapping is a key component of interdisciplinary land change science, which uses it to determine the consequences of land change on climate. Land change modeling is used to predict and analyze changes in land cover and use.
Soil

Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Soil consists of a solid phase of minerals and organic matter (the soil matrix),
as well as a porous phase that holds Soil gas, gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-State of matter, state system of solids, liquids, and gases. Soil is a product of several factors: the influence of
climate
Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...
, Terrain, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time.
It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering and erosion.
Given its complexity and strong internal connectedness, Soil ecology, soil ecologists regard soil as an ecosystem. Soil acts as an engineering medium, a habitat for soil organisms, a recycling system for nutrients and organic wastes, a regulator of water quality, a modifier of Atmospheric chemistry, atmospheric composition, and a medium for plant growth, making it a critically important provider of ecosystem services. Since soil has a tremendous range of available Ecological niche, niches and habitats, it contains a prominent part of the Earth's genetic diversity. A gram of soil can contain billions of organisms, belonging to thousands of species, mostly microbial and largely still unexplored.
Soil is a major component of the Earth's ecosystem. The world's ecosystems are impacted in far-reaching ways by the processes carried out in the soil, with effects ranging from ozone depletion and global warming to rainforest destruction and water pollution. With respect to Earth's
carbon cycle
The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth. Other major biogeochemical cycles include the nitrogen cycle and the water cycl ...
, soil acts as an important Carbon sink, carbon reservoir, and it is potentially one of the most reactive to human disturbance and climate change.
[{{cite journal , last1=Davidson , first1=Eric A. , last2=Janssens , first2=Ivan A. , year=2006 , title=Temperature sensitivity of soil carbon decomposition and feedbacks to climate change , url=https://www.nature.com/articles/nature04514.pdf , url-status=live , journal=Nature (journal), Nature , volume=440 , issue=9 March 2006 , pages=165‒73 , bibcode=2006Natur.440..165D , doi=10.1038/nature04514 , pmid=16525463 , archive-url=https://web.archive.org/web/20220706182824/https://www.nature.com/articles/nature04514.pdf , archive-date=July 6, 2022 , access-date=April 3, 2022 , doi-access=free , s2cid=4404915] As the planet warms, it has been predicted that soils will add carbon dioxide to the atmosphere due to increased Soil biology, biological activity at higher temperatures, a positive feedback (amplification). This prediction has, however, been questioned on consideration of more recent knowledge on soil carbon turnover.
Continental crust
{{Main, Continental crust, Continental shelf
{{See also, Abundance of elements in Earth's crust
Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called ''sial'' because its bulk composition is richer in aluminium silicate and has a lower density compared to the oceanic crust, called ''Sima (geology), sima'' which is richer in magnesium silicate. Changes in seismic wave velocities have shown that at a certain depth (the Conrad discontinuity), there is a reasonably sharp contrast between the more felsic upper continental crust and the lower continental crust, which is more mafic in character.
The composition of land is not uniform across the Earth, varying between locations and between strata within the same location. The most prominent components of upper continental crust include silicon dioxide, aluminium oxide, and magnesium.
[{{Cite book , last1=Rudnick , first1=Roberta L. , url=https://www.sciencedirect.com/referencework/9780080983004/treatise-on-geochemistry , title=Treatise on Geochemistry , last2=Gao , first2=S. , publisher=Elsevier , year=2014 , isbn=978-0-08-098300-4 , editor1-last=Holland , editor1-first=Heinrich D. , editor1-link=Heinrich Holland , edition=2nd , volume=4: The Crust , pages=1–51 , chapter=Composition of the Continental Crust , author1-link=Roberta Rudnick , access-date=September 3, 2022 , editor2-last=Turekian , editor2-first=Karl K. , editor2-link=Karl Turekian , chapter-url=https://www.sciencedirect.com/science/article/pii/B9780080959757003016 , archive-url=https://web.archive.org/web/20220903010959/https://www.sciencedirect.com/referencework/9780080983004/treatise-on-geochemistry , archive-date=September 3, 2022 , url-status=live] The
continental crust
Continental crust is the layer of igneous, metamorphic, and sedimentary rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as '' continental shelves''. This layer is sometimes called '' si ...
consists of lower density material such as the igneous rocks granite and andesite. Less common is basalt, a denser volcanic rock that is the primary constituent of the ocean floors.
[{{cite web , author=Staff , title=Layers of the Earth , url=http://volcano.oregonstate.edu/vwdocs/vwlessons/plate_tectonics/part1.html , url-status=dead , archive-url=https://web.archive.org/web/20130211014443/http://volcano.oregonstate.edu/vwdocs/vwlessons/plate_tectonics/part1.html , archive-date=February 11, 2013 , access-date=March 11, 2007 , work=Volcano World , publisher=Oregon State University] Sedimentary rock is formed from the accumulation of sediment that becomes buried and Diagenesis, compacted together. Nearly 75% of the continental surfaces are covered by sedimentary rocks, although they form about 5% of the crust.
[{{cite web , last1=Jessey , first1=David , title=Weathering and Sedimentary Rocks , url=http://geology.csupomona.edu/drjessey/class/Gsc101/Weathering.html , url-status=dead , archive-url=https://web.archive.org/web/20070703170212/http://geology.csupomona.edu/drjessey/class/Gsc101/Weathering.html , archive-date=July 3, 2007 , access-date=March 20, 2007 , website=California State Polytechnic University, Pomona]
The most abundant silicate minerals on Earth's surface include quartz, feldspars, amphibole, mica, pyroxene and olivine.
[{{cite book , last1=de Pater , first1=Imke , title=Planetary Sciences , last2=Lissauer , first2=Jack J. , date=2010 , publisher=Cambridge University Press , isbn=978-0-521-85371-2 , edition=2nd , page=154 , author1-link=Imke de Pater , author2-link=Jack J. Lissauer] Common carbonate minerals include calcite (found in limestone) and Dolomite (mineral), dolomite.
[{{cite book , last1=Wenk , first1=Hans-Rudolf , title=Minerals: their constitution and origin , last2=Bulakh , first2=Andreĭ Glebovich , date=2004 , publisher=Cambridge University Press , isbn=978-0-521-52958-7 , page=359 , author1-link=Hans-Rudolf Wenk , author2-link=:ru:Булах, Андрей Глебович] The rock that makes up land is thicker than oceanic crust, and it is far more varied in terms of composition. About 31% of this continental crust is submerged in shallow water, forming continental shelves.
Life science
{{Main, Terrestrial ecosystem, Landscape ecology
Land provides many
ecosystem service
Ecosystem services are the various benefits that humans derive from ecosystems. The interconnected living and non-living components of the natural environment offer benefits such as pollination of crops, clean air and water, decomposition of wast ...
s, such as mitigating climate change, regulating water supply through drainage basins and river systems, and supporting food production. Land resources are finite, which has led to regulations intended to safeguard these ecosystem services, and a set of practices called sustainable land management.
Land biomes
{{Main, Biome
A biome is an area "characterized by its vegetation, soil, climate, and wildlife."
[{{Cite web , date=May 20, 2022 , title=The Five Major Types of Biomes {{! National Geographic Society , url=https://education.nationalgeographic.org/resource/five-major-types-biomes/ , access-date=October 4, 2022 , website=National Geographic , archive-date=October 8, 2022 , archive-url=https://web.archive.org/web/20221008074316/https://education.nationalgeographic.org/resource/five-major-types-biomes/ , url-status=live] There are five major types of biomes on land: grasslands, forests, deserts, tundras, and freshwater.
Other types of biomes include shrublands,{{efn, World Wildlife Fund's definition of 14 biomes includes Temperate grasslands, savannas and shrublands, Mediterranean forests, woodlands, and scrub, and Deserts and xeric shrublands.
[{{cite web , url=https://www.arcgis.com/apps/View/index.html?appid=d60ec415febb4874ac5e0960a6a2e448 , title=WWF Terrestrial Ecoregions Of The World (Biomes) , publisher=World Wildlife Fund , access-date=October 11, 2022 , archive-date=July 13, 2022 , archive-url=https://web.archive.org/web/20220713001111/https://www.arcgis.com/apps/View/index.html?appid=d60ec415febb4874ac5e0960a6a2e448 , url-status=live] wetlands,{{efn, World Wildlife Fund's definition of 14 biomes includes Flooded grasslands and savannas, and Mangroves, which are both wetlands.
and polar ice caps. An ecosystem refers to the interaction between organisms within a particular environment, and a habitat refers to the environment where a given species or population of organisms lives. Biomes may span more than one continent, and contain a variety of ecosystems and habitats.
* Deserts have an arid climate, generally defined to mean that they receive less than {{convert, 25, cm, in of
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
per year. They make up around one fifth of the Earth's land area, are found on every continent, and can be very hot or very cold (see polar desert). They are home to animals and plants which evolved to be tolerant of droughts. In deserts, most erosion is caused by running water, usually during violent thunderstorms, which cause flash floods. Deserts are expanding due to desertification, which is caused by excessive deforestation and overgrazing.
{{Rp, pages=598–621
* Tundra is a biome where tree growth is hindered by frigid temperatures and short growing seasons. There are types of tundra associated with different regions: Arctic tundra, alpine tundra, and Antarctic tundra.
[{{cite web , title=The Tundra Biome , url=http://www.ucmp.berkeley.edu/glossary/gloss5/biome/tundra.html , url-status=live , archive-url=https://web.archive.org/web/20160121074551/http://www.ucmp.berkeley.edu/glossary/gloss5/biome/tundra.html , archive-date=January 21, 2016 , access-date=March 5, 2006 , work=The World's Biomes , publisher=University of California, Berkeley][{{cite web , title=Terrestrial Ecoregions: Antarctica , url=http://www.nationalgeographic.com/wildworld/profiles/terrestrial_an.html , url-status=dead , archive-url=https://web.archive.org/web/20110805095438/http://www.nationalgeographic.com/wildworld/profiles/terrestrial_an.html , archive-date=August 5, 2011 , access-date=November 2, 2009 , work=Wild World , publisher=National Geographic Society]
* A forest is an area of land dominated by trees. Many definitions of "forest" are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as: "land spanning more than 0.5 hectares with trees higher than 5 meters and a Canopy (biology), canopy cover of more than 10 per cent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use."
[{{Cite book , url=http://www.fao.org/3/I8661EN/i8661en.pdf , title=Global Forest Resources Assessment 2020 – Terms and definitions , publisher=FAO , year=2018 , location=Rome , access-date=October 11, 2022 , archive-date=December 8, 2021 , archive-url=https://web.archive.org/web/20211208192636/https://www.fao.org/3/i8661en/i8661en.pdf , url-status=live] Types of forests include rainforests, deciduous forests, and boreal forests.
* Grasslands are areas where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found, along with variable proportions of legumes like clover and other Herbaceous plant, herbs. Grasslands occur naturally on all continents except
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
and are found in most ecoregions of the
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. Types include natural, semi-natural, and agricultural grasslands. Savannas are grasslands with occasional, scattered trees.
Fauna and flora
Land plants evolved from green algae, and are called embryophytes. They include trees, shrubs, ferns, grass, moss, and flowers. Most plants are vascular plants, meaning that their tissues distribute water and minerals throughout the plant. Through photosynthesis, most plants nourish themselves from sunlight and water, breathing in carbon dioxide and breathing out oxygen. Between 20 and 50% of oxygen is produced by land vegetation.
Unlike plants, terrestrial animals are not a Monophyly, monophyletic group—that is, a group including all terrestrial animals does not encompass all lineages from a common ancestor. This is because there are organisms, such as the whale, that Evolution of cetaceans, evolved from terrestrial mammals back to an aquatic lifestyle.
[{{cite journal , last1=Garwood , first1=Russell J. , last2=Edgecombe , first2=Gregory D. , date=September 2011 , title=Early Terrestrial Animals, Evolution, and Uncertainty , journal=Evolution: Education and Outreach , location=New York , publisher=Springer Science+Business Media , volume=4 , issue=3 , pages=489–501 , doi=10.1007/s12052-011-0357-y , doi-access=free] Many megafauna of the past, such as non-avian dinosaurs, have become extinct due to extinction events, e.g. the Quaternary extinction event.
Humans and land
Land is "deeply intertwined with human development."
{{Rp, page=21 It is a crucial resource for human survival, humans depend on land for subsistence, and can develop strong symbolic attachments to it. Access to land can determine "survival and wealth," particularly in developing countries, giving rise to complex power relationships in production and consumption. Most of the world's philosophies and religions recognize a human duty of Stewardship (theology), stewardship towards land and nature.
Culture
{{Main, Earth in culture

Many humans see land as a source of "spirituality, inspiration, and beauty." Many also derive a sense of belonging from land, especially if it also belonged to their ancestors.
Various religions teach about a connection between humans and the land (such as veneration of Bhumi (goddess), Bhumi, a personification of the Earth in Hinduism, and the obligation to protect land as Hima (environmental protection), hima in Islam), and in almost every Indigenous group there are etiological stories about the land they live on.
For Indigenous peoples, connection to the land is an important part of their identity and culture,
[{{cite web , url=http://www.un.org/development/desa/indigenouspeoples/wp-content/uploads/sites/19/2021/03/State-of-Worlds-Indigenous-Peoples-Vol-V-Final.pdf , title=State of the World's Indigenous Peoples, Volume V, Rights to Lands, Territories and Resources , author=United Nations Department of Economic and Social Affairs , access-date=October 20, 2022 ] and some religious groups consider a particular area of land to be sacred, such as the Holy Land in the Abrahamic religions.
Creation myths in many religions involve stories of the creation of the world by a supernatural deity or deities, including accounts wherein the land is separated from the oceans and the air. The Earth itself has often been personified as a deity, in particular a goddess. In many cultures, the mother goddess is also portrayed as a fertility deity. To the Aztecs, Earth was called ''Tonantzin''—"our mother"; to the Incas, Earth was called ''Pachamama''—"mother earth". In Norse mythology, the Earth giantess Jörð was the mother of Thor and the daughter of Annar. Ancient Egyptian religion, Ancient Egyptian mythology is different from that of other cultures because Earth (Geb) is male and the sky (Nut (goddess), Nut) is female.
Ancient Near Eastern cultures conceived of the world as a flat disk of land surrounded by ocean. The Pyramid Texts and Coffin Texts reveal that the ancient Egyptians believed Nu (mythology), Nun (the ocean) was a circular body surrounding ''nbwt'' (a term meaning "dry lands" or "islands"). The Hebrew Bible, drawing on other Near Eastern ideas, Biblical cosmology#Earth, depicts the Earth as a flat disc floating on water, with another expanse of water above it.
[{{Cite book , last=Berlin , first=Adele , title=The Oxford Dictionary of the Jewish Religion , publisher=Oxford University Press , year=2011 , isbn=978-0-19-973004-9 , editor1-last=Berlin , editor1-first=Adele , chapter=Cosmology and creation , author-link=Adele Berlin , editor2-last=Grossman , editor2-first=Maxine , chapter-url=https://books.google.com/books?id=hKAaJXvUaUoC&q=Bible+Cosmology&pg=PA189 , archive-url=https://web.archive.org/web/20160611032518/https://books.google.com/books?id=hKAaJXvUaUoC&pg=PA189&dq=Bible+Cosmology&hl=en&sa=X&ei=jvHuTu_wDcStiQeFz62dBw&ved=0CGcQ6AEwCTgo#v=onepage&q=Bible%20Cosmology&f=false , archive-date=June 11, 2016 , url-status=live , via=Google Books , pages=188–189] A similar model is found in the Homeric account of the 8th century BC in which "Okeanos, the personified body of water surrounding the circular surface of the Earth, is the begetter of all life and possibly of all gods."
The spherical form of the Earth was suggested by early Greek philosophers, a belief espoused by Pythagoras. Contrary to popular belief, most educated people in the Middle Ages did not believe the Earth was flat: this misconception is often called the "Myth of the Flat Earth". As evidenced by thinkers such as Thomas Aquinas, the European belief in a spherical Earth was widespread by this point in time. Prior to Magellan expedition, circumnavigation of the planet and the introduction of space flight, belief in a spherical Earth was based on observations of the secondary effects of the Earth's shape and parallels drawn with the shape of other planets.
Travel
{{Main, Travel

Humans have commonly traveled for business, pleasure, discovery, and adventure, all made easier in recent human history as a result of technologies like cars, trains, Airplane, planes, and ships. Land navigation is an aspect of travel and refers to progressing through unfamiliar terrain using navigational tools like maps with references to terrain, a compass, or satellite navigation.
[{{cite book , last1=Hofmann-Wellenhof , first1=Bernhard , first2=K. , last2=Legat , first3=M. , last3=Wieser , first4=H. , last4=Lichtenegger , title=Navigation: Principles of Positioning and Guidances , year=2007 , publisher=Springer Science+Business Media, Springer , isbn=978-3-211-00828-7 , pages=5–6] Navigation on land is often facilitated by reference to landmarks – enduring and recognizable natural or artificial features that stand out from their nearby environment and are often visible from long distances. Natural landmarks can be characteristic features, such as mountains or plateaus, with examples including Table Mountain in South Africa, Mount Ararat in Turkey, the
Grand Canyon
The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a mile ().
The canyon and adjacent rim are contained within Grand Canyon Nati ...
in the United States, Uluru in Australia, and Mount Fuji in Japan.
[{{cite web, date=June 2012 , title=2012 Tourism Highlights , url=http://mkt.unwto.org/sites/all/files/docpdf/unwtohighlights12enlr_1.pdf , url-status=dead , archive-url=https://web.archive.org/web/20120709215809/http://mkt.unwto.org/sites/all/files/docpdf/unwtohighlights12enlr_1.pdf , archive-date=July 9, 2012 , access-date=June 17, 2012 , publisher=World Tourism Organization]
Two major eras of exploration occurred in human history: one of divergence, and one of convergence. The former saw humans moving out of Africa, settling in new lands, and developing distinct cultures in relative isolation.
[{{Cite book , last=Fernández-Armesto , first=Felipe , url=https://books.google.com/books?id=6bYQAAAAQBAJ , title=Pathfinders: A Global History of Exploration , date=2007 , publisher=W. W. Norton & Company , isbn=978-0-393-24247-8 , language=en , access-date=October 6, 2022 , archive-url=https://web.archive.org/web/20221016144552/https://books.google.com/books?id=6bYQAAAAQBAJ , archive-date=October 16, 2022 , url-status=live , via=Google Books] Early explorers settled in Europe and Asia; 14,000 years ago, some crossed the Settlement of the Americas, Ice Age land bridge from Siberia to Alaska and moved southbound to settle in the Americas.
[{{Cite book , author=Royal Geographical Society , url=https://books.google.com/books?id=uo8SAQAAIAAJ , title=Atlas of Exploration , date=2008 , publisher=Oxford University Press , isbn=978-0-19-534318-2 , language=en , access-date=October 6, 2022 , archive-url=https://web.archive.org/web/20221016144552/https://books.google.com/books?id=uo8SAQAAIAAJ , archive-date=October 16, 2022 , url-status=live , via=Google Books] For the most part, these cultures were ignorant of each other's existence.
The second period, occurring over roughly the last 10,000 years, saw increased cross-cultural exchange through trade and exploration, marking a new era of cultural intermingling.
Trade
{{Main, Trade, Timeline of international trade
Human trade has occurred since the prehistoric era. Peter Watson (business writer), Peter Watson dates the History of international trade, history of long-distance commerce from
c. 150,000 years ago.
[{{cite book , last=Watson , first=Peter , author-link=Peter Watson (intellectual historian) , year=2005 , title=Ideas: A History of Thought and Invention from Fire to Freud , location=New York , publisher=HarperCollins Publishers , isbn=978-0-06-621064-3 , at=Introduction] Major trade routes throughout history have existed on land, such as the Silk Road which linked East Asia with
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
and the Amber Road which was used to transfer amber from Northern Europe to the Mediterranean Sea. The Dark Ages (historiography), Dark Ages led trade to collapse in the West, but it continued to flourish among the kingdoms of Africa, the Middle East, India, China, and Southeast Asia. During the Middle Ages, Central Asia was the economic centre of the world, and luxury goods were commonly traded in Europe. Physical money (either barter or precious metals) was dangerous to carry over a long distance. To address this, a burgeoning banking industry enabled the shift to movable wealth or capital, making it far easier and safer to trade across long distances. After the Age of Sail, international trade mostly occurred along sea routes, notably to prevent intermediary countries from being able to control trade routes and the flow of goods.{{Citation needed, date=October 2022
In economics, Land (economics), ''land'' refers to a factor of production. It can be leased in exchange for Renting, rent, and use of its various raw material resources (trees, oil, metals).
Land use
{{Main, Land use, Land consumption
For more than 10,000 years, humans have engaged in activities on land such as hunting, foraging, controlled burning, land clearing, and
agriculture
Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...
. Beginning with the Neolithic Revolution and the spread of agriculture around the world, human land use has significantly altered
terrestrial ecosystem
Terrestrial ecosystems are ecosystems that are found on land. Examples include tundra, taiga, temperate deciduous forest, tropical rain forest, grassland, deserts.
Terrestrial ecosystems differ from aquatic ecosystems by the predominant presen ...
s, with an essentially global transformation of Earth's landscape by 3000 years ago.
[{{cite report , title=Global Land Outlook , date=2017 , publisher=United Nations Convention to Combat Desertification , isbn=978-92-95110-48-9 , access-date=November 3, 2022 , chapter-url=https://www.unccd.int/sites/default/files/2018-06/GLO%20English_Ch2.pdf , chapter=Chapter 2 – Brief History of Land Use]{{rp, page=30 From around 1750, human land use has increased at an accelerating rate due to the Industrial Revolution, which created a greater demand for natural resources and caused rapid population growth.
{{rp, page=34
Agriculture includes both crop farming and animal husbandry.
[{{cite book , title=Safety and health in agriculture , url={{google books, plainurl=y, id=GtBa6XIW_aQC, page=77 , year=1999 , publisher=International Labour Organization , isbn=978-92-2-111517-5 , page=77 , access-date=September 13, 2010 , url-status=live , archive-url=https://web.archive.org/web/20110722061757/http://books.google.com/books?id=GtBa6XIW_aQC , archive-date=July 22, 2011 , quote=defined agriculture as 'all forms of activities connected with growing, harvesting and primary processing of all types of crops, with the breeding, raising and caring for animals, and with tending gardens and nurseries'. , via=Google Books] A third of Earth's land surface is used for agriculture,
[{{Cite web , title=Agricultural land (% of land area) {{! Data , url=https://data.worldbank.org/indicator/AG.LND.AGRI.ZS , url-status=live , archive-url=https://web.archive.org/web/20190530044611/https://data.worldbank.org/indicator/ag.lnd.agri.zs , archive-date=May 30, 2019 , access-date=September 25, 2022 , website=data.worldbank.org][{{cite report , title=Global Land Outlook , date=2017 , publisher=United Nations Convention to Combat Desertification , isbn=978-92-95110-48-9 , access-date=November 14, 2022 , chapter-url=https://knowledge.unccd.int/sites/default/files/2018-06/GLO%20English_Ch7.pdf , chapter=Chapter 7 – Food Security and Agriculture]{{rp, page=126 with estimated {{convert, 16.7, e6km2, e6sqmi, abbr=unit of cropland and {{convert, 33.5, e6km2, e6sqmi, abbr=unit of pastureland.
This has had significant impacts on Earth's ecosystems. When land is cleared to make way for agriculture, native flora and fauna are replaced with newly introduced crops and livestock.
{{rp, page=31 Excessively high agricultural land use is driven by poor management practices (which lead to lower food yields, necessitating more land use), food demand, food waste, and Environmental impact of meat production#Land use, diets high in meat.
{{rp, page=126
Urbanization has led to greater population growth in urban areas in the last century. Although urban areas make up less than 3 percent of Earth's land area, the global population shifted from a majority living in rural areas to a majority living in urban areas in 2007.
{{rp, page=35 People living in urban areas depend on food produced in rural areas outside of their cities, which creates greater demand for agriculture and drives land use change well beyond city boundaries.
{{rp, page=35 Urbanization also displaces agricultural land because it mainly takes place on the most fertile land. Urban expansion in peri-urban areas fragments agricultural and natural lands, forcing agriculture to move to less fertile land elsewhere. Because this land is less fertile, more land is needed for the same output, which increases the total agricultural land use.
[{{cite report , title=Global Land Outlook , date=2017 , publisher=United Nations Convention to Combat Desertification , isbn=978-92-95110-48-9 , access-date=November 14, 2022 , chapter-url=https://www.unccd.int/sites/default/files/2018-06/GLO%20English_Ch6.pdf , chapter=Chapter 6 – Scenarios of Change]{{rp, page=119
Another form of land use is mining, whereby minerals are extracted from the ground using a variety of methods. Evidence of mining activity dates back to around 3000 BCE in Ancient Egypt.
{{rp, page=34 Important minerals include iron ore, mined for use as a raw material; coal, mined for Fossil fuel, energy production; and gemstones, mined for use in jewellery and currency.
{{rp, page=34
Law
{{Main, Land law
The phrase "Law of the land, the law of the land" first appeared in 1215 in Magna Carta, inspiring its later usage in the United States Constitution. The idea of common land also originated with medieval English law, and refers collective ownership of land, treating it as a common good.
In environmental science, economics, and game theory, the tragedy of the commons refers to individuals' use of common spaces for their own gain, deteriorating the land overall by taking more than their fair share and not cooperating with others. The idea of common land suggests public ownership; but there is still some land that can be privatized as property for an individual, such as a landlord or king. In the developed world, land is expected to be privately owned by an individual with legal Title (property), title, but in the developing world the right to use land is often divided, with the rights to land resources being given to different people at different times for the same area of land.
Beginning in the late 20th century, the international community has begun to recognise Indigenous land rights in law, for example, the Treaty of Waitangi for Māori people, Māori people, the 2008 Greenlandic self-government referendum, Act on Greenland Self-Government for Inuit people, and the Indigenous Peoples Rights Act in the Philippines.
Geopolitics
{{Main, Geopolitics
{{See also, Territorial dispute, Border

Borders are geographical boundaries imposed either by geographic features (
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
s, mountain ranges,
river
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...
s) or by political entities (governments, states, or subnational entities). Political borders can be established through warfare, colonization, or mutual agreements between the political entities that reside in those areas;
[{{cite book , last=Slater , first=Terry , title=An Introduction To Human Geography , date=2016 , editor1-first=Peter , editor1-last=Daniels , editor2-first=Michael , editor2-last=Bradshaw , editor2-link=Michael J. Bradshaw , editor3-first=Denis , editor3-last=Shaw , editor4-first=James , editor4-last=Sidaway , editor5-first=Tim , editor5-last=Hall , publisher=Pearson Education, Pearson , edition=5th , isbn=978-1-292-12939-6 , page=47 , chapter=The Rise and Spread of Capitalism , author-link=Terry Slater (geographer)] the creation of these agreements is called National boundary delimitation, boundary delimitation.
[{{cite book , last1=Sidaway , first1=James , title=An Introduction To Human Geography , last2=Grundy-Warr , first2=Carl , date=2016 , editor1-first=Peter , editor1-last=Daniels , editor2-first=Michael , editor2-last=Bradshaw , editor2-link=Michael J. Bradshaw , editor3-first=Denis , editor3-last=Shaw , editor4-first=James , editor4-last=Sidaway , editor5-first=Tim , editor5-last=Hall , publisher=Pearson Education, Pearson , edition=5th , isbn=978-1-292-12939-6 , page=449 , chapter=The Place of the Nation-State]
Many wars and other conflicts have occurred in efforts by participants to expand the land under their control, or to assert control of a specific area of considered to hold strategic, historical, or cultural significance. The Mongol Empire of the 13th and 14th centuries became the List of largest empires, largest contiguous land empire in human history, history through war and conquest.
In the 19th century in the United States, 19th-century United States, a concept of manifest destiny was developed by various groups, asserting that American settlers were destined to expand across
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
. This concept was used to justify military action against the indigenous peoples of North America and Indigenous peoples of Mexico, of Mexico.
[{{cite book , last1=Merk , first1=Frederick , url=https://books.google.com/books?id=GhYJTaZiuxwC&pg=PA215 , title=Manifest Destiny and Mission in American History , last2=Merck , first2=Lois Bannister , year=1963 , isbn=978-0674548053 , pages=215–216 , publisher=Harvard University Press , via=Google Books ]
The aggression of Nazi Germany in World War II was motivated in part by the concept of ''Lebensraum'' ("living space"), which had first became a geopolitical goal of Imperial Germany in World War I (1914–1918) originally, as the core element of the {{lang, de, Septemberprogramm of territorial expansion.
[{{cite book , url=https://archive.org/details/penguindictionar0000evan , title=Penguin Dictionary of International relations , publisher=Penguin Books , year=1998 , isbn=978-0140513974 , editor1-last=Evans , editor1-first=Graham , pag]
301
, i
, editor2-last=Newnham , editor2-first=Jeffrey , url-access=registration The most extreme form of this ideology was supported by the Nazi Party (NSDAP). Lebensraum was one of the leading motivations Nazi Germany had in initiating World War II, and it would continue this policy until the end of World War II.
[{{cite book , last=Smith , first=Woodruff D. , title=The Ideological Origins of Nazi Imperialism , publisher=Oxford University Press , page=84]
Environmental issues
{{Main, Land degradation

Land degradation is "the reduction or loss of the biological or economic productivity and complexity" of land as a result of human activity.
[{{cite report , title=Global Land Outlook , date=2017 , publisher=United Nations Convention to Combat Desertification , isbn=978-92-95110-48-9 , access-date=November 4, 2022 , chapter-url=https://www.unccd.int/sites/default/files/2018-06/GLO%20English_Ch3_0.pdf , chapter=Chapter 3 – Drivers of Change]{{rp, page=42 Land degradation is driven by many different activities, including agriculture, urbanization, energy production, and mining.
{{rp, page=43 Humans have altered more than three-quarters of ice-free land through habitation and other use, fundamentally changing ecosystems.
[{{Cite journal , last1=Ellis , first1=Erle C. , author1-link=Erle Ellis , last2=Ramankutty , first2=Navin , author2-link=Navin Ramankutty , date=October 1, 2008 , title=Putting people in the map: anthropogenic biomes of the world , journal=Frontiers in Ecology and the Environment , language=en , volume=6 , issue=8 , pages=439–447 , doi=10.1890/070062 , issn=1540-9295 , s2cid=3598526 , doi-access=free, bibcode=2008FrEE....6..439E ] Human activity is a major factor in the Holocene extinction, and human-caused climate change is causing rising sea levels and ecosystem loss. Environmental scientists study land's ecosystems, natural resources,
biosphere
The biosphere (), also called the ecosphere (), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to mat ...
(fauna and flora),
troposphere
The troposphere is the lowest layer of the atmosphere of Earth. It contains 80% of the total mass of the Atmosphere, planetary atmosphere and 99% of the total mass of water vapor and aerosols, and is where most weather phenomena occur. From the ...
, and the impact of human activity on these.
Their recommendations have led to international action to prevent biodiversity loss and desertification, and encourage sustainable forest management, forest and waste management, waste management.
The conservation movement lobbies for the protection of
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
and the protection of natural areas, such as parks.{{rp, page=253 International frameworks have focused on analyzing how humans can meet their needs while using land more efficiently and preserving its natural resources, notably under the United Nations' Sustainable Development Goals framework.
[{{Cite web , title=Goal 15 {{! Department of Economic and Social Affairs , url=https://sdgs.un.org/goals/goal15 , url-status=live , archive-url=https://web.archive.org/web/20220926130028/https://sdgs.un.org/goals/goal15 , archive-date=September 26, 2022 , access-date=September 26, 2022 , website=]United Nations
The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...
Soil degradation
{{Main, Soil retrogression and degradation
Human land use can cause soil to degrade, both in quality and in quantity.
{{rp, page=44 Soil degradation can be caused by agrochemicals (such as fertilizers, pesticides, and herbicides), infrastructure development, and mining among other activities.
{{rp, pages=43–47 There are several different processes that lead to soil degradation. Physical processes, such as Soil erosion, erosion, Soil sealing, sealing, and Soil crust#Physical soil crusts, crusting, lead to the structural breakdown of the soil. This means water cannot penetrate the soil surface, causing surface runoff.
{{rp, page=44 Chemical processes, such as Soil salinity, salinization, Soil acidification, acidification, and toxication, lead to chemical imbalances in the soil.
{{rp, page=44 Salinization in particular is detrimental, as it makes land less productive for agriculture and affects at least 20% of all irrigated lands.
{{rp, page=137 Deliberate disruption of soil in the form of tillage can also alter biological processes in the soil, which leads to excessive Mineralization (soil science), mineralization and the loss of nutrients.
{{rp, page=44
Desertification is a type of land degradation in drylands in which fertile areas become increasingly arid as a result of natural processes or human activities, resulting in loss of biological productivity. This spread of arid areas can be influenced by a variety of human factors, such as deforestation, improper land management, overgrazing,
anthropogenic
climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
,
[{{Cite journal , last1=Zeng , first1=Ning , last2=Yoon , first2=Jinho , date=September 1, 2009 , title=Expansion of the world's deserts due to vegetation-albedo feedback under global warming , journal=Geophysical Research Letters , volume=36 , issue=17 , page=L17401 , bibcode=2009GeoRL..3617401Z , doi=10.1029/2009GL039699 , issn=1944-8007 , s2cid=1708267, doi-access=free ] and overexploitation of
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
. Throughout geological history, desertification has occurred naturally, though in recent times it is greatly accelerated by human activity.
[{{cite journal , last1=Liu , first1=Ye , last2=Xue , first2=Yongkang , date=March 5, 2020 , title=Expansion of the Sahara Desert and shrinking of frozen land of the Arctic , journal=Scientific Reports , volume=10 , issue=1 , pages=4109 , bibcode=2020NatSR..10.4109L , doi=10.1038/s41598-020-61085-0 , pmc=7057959 , pmid=32139761]
Pollution
{{Main, Pollution
Ground pollution is soil contamination via pollutants, such as hazardous waste or litter. Ground pollution can be prevented by properly monitoring and disposing of waste, along with reducing unnecessary chemical and plastic use. Unfortunately, proper disposal of waste often is not economically beneficial or technologically viable, leading to short-term solutions of waste disposal that pollute the earth. Examples include dumping harmful industrial byproducts, overusing agricultural fertilizers and other chemicals, and poorly maintaining landfills. Some landfills can be thousands of acres in size, such as the Apex landfill, Apex Regional landfill in Las Vegas.
Water pollution on land is the contamination of non-oceanic hydrological surface and underground water features such as
lakes
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...
, ponds,
rivers
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
, streams, wetlands, aquifers, reservoirs, and
groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...
as a result of human activities.
[{{Cite journal , last=Von Sperling , first=Marcos , date=2015 , title=Wastewater Characteristics, Treatment and Disposal , url=https://iwaponline.com/ebooks/book/72/ , journal=IWA Publishing , volume=6 , doi=10.2166/9781780402086 , isbn=978-1780402086 , doi-access=free , access-date=September 26, 2022 , archive-date=June 21, 2022 , archive-url=https://web.archive.org/web/20220621151651/https://iwaponline.com/ebooks/book/72/ , url-status=live]{{rp, 6 It may be caused by toxic substances (e.g., oil, metals, plastics, pesticides, persistent organic pollutants, industrial waste products),
[{{cite book , url=http://unix.eng.ua.edu/~rpitt/Publications/BooksandReports/Stormwater%20Effects%20Handbook%20by%20%20Burton%20and%20Pitt%20book/MainEDFS_Book.html , title=Stormwater Effects Handbook: A Toolbox for Watershed Managers, Scientists, and Engineers , chapter=2 , publisher=CRC Press, CRC/Lewis Publishers , year=2001 , isbn=0-87371-924-7 , location=New York , vauthors=Burton Jr GA, Pitt R , access-date=January 26, 2009 , archive-date=May 19, 2009 , archive-url=https://web.archive.org/web/20090519035716/http://unix.eng.ua.edu/~rpitt/Publications/BooksandReports/Stormwater%20Effects%20Handbook%20by%20%20Burton%20and%20Pitt%20book/MainEDFS_Book.html , url-status=dead] stressful conditions (e.g., changes of pH, Hypoxia (environmental), hypoxia or anoxia, increased temperatures, excessive turbidity, unpleasant taste or odor, and changes of salinity), or Pathogen, pathogenic organisms.
[{{Cite journal , last=Von Sperling , first=Marcos , date=2015 , title=Wastewater Characteristics, Treatment and Disposal , page=47 , url=https://iwaponline.com/ebooks/book/72/ , journal=IWA Publishing , volume=6 , isbn=978-1780402086 , doi=10.2166/9781780402086 , doi-access=free , access-date=September 26, 2022 , archive-date=June 21, 2022 , archive-url=https://web.archive.org/web/20220621151651/https://iwaponline.com/ebooks/book/72/ , url-status=live]
Biodiversity loss
{{Main, Biodiversity loss, Habitat destruction
The
biodiversity
Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...
of Earth{{Emdashthe variety and variability of life{{Emdashis threatened by climate change, human activities, and invasive species. Due to an increase in the rate of extinction, biodiversity loss is increasing. Agriculture can cause biodiversity loss as land is converted for agricultural use at a very high rate, particularly in the tropics, which directly causes habitat loss. The use of pesticides and herbicides can also negatively impact the health of local species.
{{rp, page=43 Ecosystems can also be divided and degraded by infrastructure development outside of urban areas.
{{rp, page=46
Biodiversity loss can sometimes be reversed through ecological restoration or ecological resilience, such as through the restoration of abandoned agricultural areas;
{{rp, page=45 however, it may also be permanent (e.g. through land loss). The planet's ecosystem is quite sensitive: occasionally, minor changes from a healthy Equilibrium point, equilibrium can have dramatic influence on a food web or food chain, up to and including the coextinction of that entire food chain. Biodiversity loss leads to reduced ecosystem services, and can eventually threaten food security.
[{{cite journal , display-authors=3 , vauthors=Cardinale BJ, Duffy JE, Gonzalez A, Hooper DU, Perrings C, Venail P, Narwani A, Mace GM, Tilman D, Wardle DA, Kinzig AP, Daily GC, Loreau M, Grace JB, Larigauderie A, Srivastava DS, Naeem S , date=June 2012 , title=Biodiversity loss and its impact on humanity , url=https://pub.epsilon.slu.se/10240/7/wardle_d_etal_130415.pdf , journal=Nature (journal), Nature , volume=486 , issue=7401 , pages=59–67 , bibcode=2012Natur.486...59C , doi=10.1038/nature11148 , pmid=22678280 , quote=...at the first Earth Summit, the vast majority of the world's nations declared that human actions were dismantling the Earth's ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper. , s2cid=4333166 , access-date=September 26, 2022 , archive-date=September 21, 2017 , archive-url=https://web.archive.org/web/20170921233215/http://pub.epsilon.slu.se/10240/7/wardle_d_etal_130415.pdf , url-status=live] Earth is currently undergoing its sixth mass extinction (the ''Holocene extinction'') as a result of human activities which push beyond the planetary boundaries. So far, this extinction has proven irreversible.
[{{cite journal , display-authors=3 , vauthors=Bradshaw CJ, Ehrlich PR, Beattie A, Ceballos G, Crist E, Diamond J, Dirzo R, Ehrlich AH, Harte J, Harte ME, Pyke G, Raven PH, Ripple WJ, Saltré F, Turnbull C, Wackernagel M, Blumstein DT , date=2021 , title=Underestimating the Challenges of Avoiding a Ghastly Future , journal=Frontiers in Conservation Science , volume=1 , doi=10.3389/fcosc.2020.615419 , doi-access=free]
Resource depletion
{{Main, Overexploitation, Conflict resource
Although humans have used land for its
natural resources
Natural resources are resources that are drawn from nature and used with few modifications. This includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. ...
since ancient times, demand for resources such as timber, minerals, and energy has grown exponentially since the Industrial Revolution due to population growth.
{{rp, page=34 When a natural resource is depleted to the point of diminishing returns, it is considered the overexploitation of that resource. Some natural resources, such as timber, are considered renewable, because with sustainable practices they replenish to their previous levels.
[{{cite report , title=Global Land Outlook , date=2017 , publisher=United Nations Convention to Combat Desertification , isbn=978-92-95110-48-9 , access-date=November 3, 2022 , chapter-url=https://knowledge.unccd.int/sites/default/files/2018-06/GLO%20English_Ch5.pdf , chapter=Chapter 5 – Land Resources and Human Security]{{rp, page=90 Fossil fuels such as coal are not considered renewable, as they take millions of years to form, with the current supply of coal expected to peak in the middle of the 21st century.
{{rp, page=90 Economic materialism, or consumerism, has influenced destructive patterns of modern resource usage, in contrast with pre-industrial usage.
[{{Cite journal , last1=Wang , first1=Luxiao , last2=Gu , first2=Dian , last3=Jiang , first3=Jiang , last4=Sun , first4=Ying , date=April 5, 2019 , title=The Not-So-Dark Side of Materialism: Can Public Versus Private Contexts Make Materialists Less Eco-Unfriendly? , journal=Frontiers in Psychology , volume=10 , pages=790 , doi=10.3389/fpsyg.2019.00790 , issn=1664-1078 , pmc=6460118 , pmid=31024411, doi-access=free]
Gallery
Different varieties of landscapes:
File:2010 New York City Central Park aerial.jpg, Central Park, New York City, alt=parkland in the middle of a big city
File:Libya 4985 Tadrart Acacus Luca Galuzzi 2007.jpg, Sahara Desert, Libya, alt=sand hills in a desert
File:7 - Itahuania - Août 2008.JPG, Amazon rainforest, Peru, alt=a large forest
File:Mount Vinson from NW at Vinson Plateau by Christian Stangl (flickr).jpg, Permafrost, Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
, alt=Ice and snow on the ground
File:Spiaggia rosa, isola di budelli, sardegna.jpg, Coast, Seaside in Budelli, Italy
File:Foopass.jpg, Meadow in the Swiss Alps, alt=a meadow between mountains
File:Farming near Klingerstown, Pennsylvania.jpg, Farmland in Pennsylvania, alt=Hilly farmland
See also
* Public land
* Solid earth
Notes
{{notelist
References
{{reflist
{{Natural resources
{{Subject bar, wikt=land, q=Land, portal1=Geography, portal2=Earth sciences
{{Authority control
Physical geography
Geography terminology
Geomorphology