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Natural environment facts for kids

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Hopetoun falls
Land management has preserved the natural characteristics of Hopetoun Falls, Australia while allowing ample access for visitors.
Sahara satellite hires
An image of the Sahara Desert from satellite. It is the world's largest hot desert and third-largest desert after the polar deserts.

The natural environment or natural world includes everything around us that is not made by people. This means all living things, like plants and animals, and non-living things, like rocks, water, and air. It's usually about Earth or parts of it. This environment shows how all living things, weather, and natural resources work together. These interactions are vital for human survival and our daily lives.

We can think of the natural environment in two main ways:

  • Complete ecological units that work as natural systems without much human interference. This includes all plants, tiny living things, soil, rocks, mountains, the air, and natural events like storms.
  • Big natural resources and physical events that don't have clear borders. Examples are air, water, and climate. Also, energy, radiation, and magnetism that don't come from human actions.

The opposite of the natural environment is the built environment. Built environments are places where humans have greatly changed the land. Think of cities or farms. In these places, the natural world is changed into a simpler human-made one. Even small actions, like building a mud hut in the desert, turn the area into something artificial. While many animals build things for themselves, like beaver dams, these are still considered natural.

No place on Earth is 100% natural anymore. Naturalness is a scale, from completely wild to completely changed by humans. Big changes by humans, especially in recent times, have affected all natural environments. These changes include climate change, losing many different species, and pollution from plastics and other chemicals in the air and water. We can look at different parts of an environment and see how natural they are. For example, a farm field's soil might have similar minerals to a wild forest, but its structure is very different.

Earth's Natural Systems

Jordens inre-numbers
Earth's layered structure: (1) inner core; (2) outer core; (3) lower mantle; (4) upper mantle; (5) lithosphere; (6) crust

Scientists who study Earth generally divide it into four main parts, or "spheres." These are the lithosphere (rocks), the hydrosphere (water), the atmosphere (air), and the biosphere (life). Some scientists also add the cryosphere (ice) and the pedosphere (soil). Earth science is a big field that uses physics, chemistry, biology, and mathematics. It helps us understand these main parts of Earth.

Earth's Moving Crust

The Earth's crust is its solid outer layer. It is different from the mantle below it. The crust formed from hot magma cooling down and becoming solid rock. The mantle is heated by energy from inside the Earth. Even though the mantle is solid, it moves very slowly. This slow movement causes the Earth's crustal plates to move. This process is called plate tectonics. Volcanoes happen when rock melts deep inside the Earth or when magma rises at places like mid-ocean ridges.

Water on Our Planet

Blue Linckia Starfish
Coral reefs have significant marine biodiversity.

Most of Earth's water is found in different natural bodies of water.

Oceans: Earth's Giant Water Bodies

An ocean is a huge body of salty water. Oceans cover about 71% of the surface of the Earth. This is a massive area of about 362 million square kilometers. All these waters are connected, forming one "World Ocean." More than half of this area is deeper than 3,000 meters (9,800 feet). Ocean water is usually about 3.5% salt. The deep seabeds are vast and are some of the least changed natural places. The main oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

Rivers: Flowing Freshwater

A river is a natural watercourse, usually with freshwater. Rivers flow towards an ocean, a lake, a sea, or another river. Some rivers flow into the ground and dry up before reaching another body of water.

Hawaii Creek
Rocky stream in the U.S. state of Hawaii

River water usually flows in a channel. This channel has a stream bed and banks. Larger rivers often have a wider floodplain. This floodplain is shaped by water overflowing the channel during floods. Rivers are a key part of the hydrological cycle, which is how water moves around Earth. Water in a river comes from rain, groundwater, springs, and melting glaciers or snow.

Smaller rivers can also be called streams, creeks, or brooks. They are important "corridors" for wildlife. They help connect different habitats and protect biodiversity. The study of streams and waterways is called surface hydrology.

Lakes: Inland Water Basins

LAGO LACAR
Lácar Lake, of glacial origin, in the province of Neuquén, Argentina

A lake is a body of water found in a basin on land. It is considered a lake if it is inland, not part of an ocean, and larger and deeper than a pond.

Natural lakes are often found in mountains, rift zones, or areas where glaciers have recently been. Other lakes are in dry basins or along large rivers. Many lakes exist in some parts of the world because of the last ice age. All lakes are temporary over very long periods. They will slowly fill with dirt or drain out of their basins.

Ponds: Smaller Still Waters

A pond is a smaller body of still water. It can be natural or human-made. Ponds are usually smaller than lakes. Many human-made water bodies are called ponds. These include water gardens for beauty, fish ponds for raising fish, and solar ponds for storing heat. Ponds and lakes are different from streams because their water moves much slower.

How Humans Affect Water

People impact water in many ways. We change rivers by building dams and straightening channels. We also affect water through urbanization (building cities) and deforestation (cutting down forests). These actions can change lake levels, groundwater, and cause water pollution or thermal pollution.

Dams can create useful reservoirs and hydroelectric power. However, they can also harm the environment and wildlife. Dams stop fish from migrating and block the movement of other organisms. Urbanization and deforestation often go together. Cutting down forests can lead to floods, less water in streams, and changes in plants along rivers. When plants don't get enough water, they suffer, which means less food for local wildlife.

Air, Climate, and Weather

Top of Atmosphere
Atmospheric gases scatter blue light more than other wavelengths, creating a blue halo when seen from space.
Troposphere CIMG1853
A view of Earth's troposphere from an airplane
Lightnings sequence 2 animation-wcag
Lightning is an atmospheric discharge of electricity accompanied by thunder, which occurs during thunderstorms and certain other natural conditions.

Earth's atmosphere is a thin layer of gases held by the planet's gravity. It is essential for life. Dry air is mostly 78% nitrogen, 21% oxygen, and 1% argon, plus other inert gases and carbon dioxide. It also contains greenhouse gases like carbon dioxide, methane, and ozone. Air also has different amounts of water vapor and tiny water droplets or ice crystals, which we see as clouds.

Unfiltered air can contain natural things like dust, pollen, spores, sea spray, volcanic ash, and tiny bits of meteoroids. Unfortunately, it can also contain industrial pollutants.

The ozone layer in the atmosphere is very important. It reduces the amount of harmful ultraviolet (UV) radiation that reaches Earth's surface. Since UV light can damage living things, this layer protects life. The atmosphere also keeps heat in at night, which helps prevent extreme temperature changes.

Layers of Earth's Atmosphere

Earth's atmosphere has five main layers. These layers are mostly defined by how temperature changes with height. From highest to lowest, they are:

  • Exosphere: The very outermost layer, mostly made of hydrogen and helium.
  • Thermosphere: This layer is above the mesosphere. The International Space Station orbits here, about 320 to 380 kilometers (200 to 236 miles) up.
  • Mesosphere: This layer extends up to about 80-85 kilometers (50-53 miles). Most meteors burn up here when they enter the atmosphere.
  • Stratosphere: This layer goes up to about 51 kilometers (32 miles). The ozone layer is found within the stratosphere.
  • Troposphere: This is the lowest layer, where we live and where most weather happens. It starts at the surface and goes up to about 7 kilometers (4 miles) at the poles and 17 kilometers (11 miles) at the equator. It's warmest at the bottom and gets colder higher up.

Other important layers include:

  • The ozone layer: Found in the stratosphere, it protects us from UV radiation.
  • The ionosphere: This part of the atmosphere is affected by the sun's energy. It stretches from 50 to 1000 kilometers (31 to 621 miles) high.

Global Warming and Its Effects

Gletscherschmelze
The retreat of glaciers since 1850 of Aletsch Glacier in the Swiss Alps (situation in 1979, 1991 and 2002), due to global warming

Scientists worldwide are studying the dangers of global warming. They are very concerned about its long-term effects on our natural environment and the planet. A big worry is how climate change and global warming, caused by human-made releases of greenhouse gases (especially carbon dioxide), can harm Earth and human life.

It is clear that our planet is warming, and quickly. This is due to the greenhouse effect. Greenhouse gases trap heat inside Earth's atmosphere. This warming also leads to the loss of natural habitats, which reduces wildlife populations. The Intergovernmental Panel on Climate Change, a group of leading climate scientists, reported that Earth's temperature increased significantly between 1990 and 2025.

Many efforts are focused on reducing greenhouse gases and finding ways to adapt to global warming. These efforts help humans, animals, plants, and ecosystems adjust to the changes. Some examples of recent teamwork to address climate change include:

Aletschgletsjer Zwitserland
Another view of the Aletsch Glacier in the Swiss Alps, which because of global warming has been decreasing
  • The United Nations Framework Convention Treaty aims to stabilize greenhouse gas levels. This prevents dangerous human interference with the climate system.
  • The Kyoto Protocol is an international treaty that also works to reduce greenhouse gases.
  • The Western Climate Initiative helps find ways to reduce greenhouse gases in its region.

It's a big challenge to tell the difference between natural environmental changes and those caused by humans.

Climate: Long-Term Weather Patterns

ClimateMap World
Worldwide climate classifications map

Climate describes the average weather conditions in a region over long periods. This includes temperature, humidity, wind, and rainfall. Weather, on the other hand, is the current condition of these elements over shorter times, like a few days or weeks.

Climates are classified by average temperatures and rainfall. The most common system was developed by Wladimir Köppen.

Weather: Daily Atmospheric Conditions

Rainbow over Bristol
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere.

Weather is all the events happening in a certain area of the atmosphere at a specific time. Most weather occurs in the troposphere, the lowest layer. "Weather" usually refers to daily temperature and precipitation. "Climate" is for average conditions over longer times.

Weather happens because of differences in temperature and moisture from one place to another. These differences are due to how much sunlight a spot receives, which changes with latitude. The big temperature difference between polar and tropical air creates the jet stream. Weather systems in the middle latitudes, like storms, are caused by the jet stream's movements.

Earth's axis is tilted, so sunlight hits different parts of the Earth at different angles throughout the year. This causes seasons. On Earth's surface, temperatures can range widely each year. Over thousands of years, changes in Earth's orbit have also affected how much solar energy the planet receives, influencing long-term climate.

Temperature differences also cause pressure differences. Higher places are cooler than lower places. Weather forecasting uses science and technology to predict the atmosphere's state. The atmosphere is a complex system, so small changes can have big effects. Humans have tried to control the weather throughout history. There is also evidence that human activities like agriculture and industry have accidentally changed weather patterns.

Life on Earth

Diversity of plants image version 5
There are many plant species on the planet.
Animal diversity
An example of the many animal species on the Earth

Scientists believe that life on Earth has existed for about 3.7 billion years. All known life forms share basic ways of working at a tiny level. Based on this, theories about the origin of life try to explain how the first simple living cell formed. This first cell is thought to be the ancestor of all life.

While there's no single definition of life, scientists generally agree that living things show certain traits. These include being organized, having metabolism (using energy), growing, adapting, reacting to things around them, and reproducing. In biology, life is what makes active organisms different from non-living matter. It includes the ability to grow, function, and change before death.

A huge variety of living organisms can be found in Earth's biosphere. These include plants, animals, fungi, protists, archaea, and bacteria. They are all based on carbon and water, have cells, and carry genetic information. Living organisms use energy, keep their internal conditions stable, grow, respond to their environment, reproduce, and adapt over generations through natural selection. More complex organisms can also communicate in many ways.

Ecosystems: Nature's Interconnected Communities

River gambia Niokolokoba National Park
Rainforests often have a great deal of biodiversity with many plant and animal species. This is the Gambia River in Senegal's Niokolo-Koba National Park.

An ecosystem is a natural unit where all plants, animals, and tiny living things (biotic factors) in an area work together. They also interact with all the non-living physical parts (abiotic factors) of their environment.

A key idea of an ecosystem is that living organisms are always connected to every other part of their environment. Eugene Odum, a founder of ecology, said an ecosystem includes all organisms in an area interacting with their physical environment. This interaction leads to energy flow, different types of life, and material cycles within the system.

Creek and old-growth forest-Larch Mountain
Old-growth forest and a creek on Larch Mountain, in the U.S. state of Oregon

Having more different kinds of species in an ecosystem can make it stronger. This is because more species can respond to changes, which helps reduce their effects. This can prevent the ecosystem from changing too much. However, this is not always true, and there isn't a proven link between species diversity and an ecosystem's ability to provide resources sustainably.

The term ecosystem can also apply to human-made environments. It describes any situation where living organisms and their environment are connected. Today, very few places on Earth are completely untouched by humans. However, some true wilderness areas still exist without human interference.

Earth's Cycles: Biogeochemical Processes

Plagiomnium affine laminazellen
Chloroplasts conduct photosynthesis and are found in plant cells and other eukaryotic organisms. These are chloroplasts visible in the cells of Plagiomnium affine — many-fruited thyme-moss.

Global biogeochemical cycles are vital for life. The most important ones involve water, oxygen, carbon, nitrogen, and phosphorus.

  • The nitrogen cycle is how nitrogen and its compounds change in nature. It includes gases.
  • The water cycle is the constant movement of water on, above, and below Earth's surface. Water can be liquid, vapor, or ice.
  • The carbon cycle is how carbon moves between living things, soil, rocks, water, and the atmosphere.
  • The oxygen cycle is how oxygen moves between the atmosphere, living things, and rocks. Photosynthesis is the main driver of this cycle.
  • The phosphorus cycle is how phosphorus moves through rocks, water, and living things. The atmosphere doesn't play a big role because phosphorus is usually solid.

Wilderness: Untouched Nature

Swiss National Park 131
A conifer forest in the Swiss Alps (National Park)
Togiak Wilderness
The Ahklun Mountains and the Togiak Wilderness within the Togiak National Wildlife Refuge in the U.S. state of Alaska

Wilderness is generally defined as a natural environment that has not been greatly changed by human activity. The WILD Foundation describes it as "the most intact, undisturbed wild natural areas left on our planet." These are places humans don't control or develop with roads or buildings. Wilderness areas and protected parks are important for many species, for scientific study, for conservation, for peace, and for recreation.

Wilderness is highly valued for cultural, spiritual, and aesthetic reasons. Some writers believe wild places are essential for the human spirit and creativity. The word "wilderness" comes from the idea of "wildness," meaning something not controlled by humans. The word's origin is from Old English wildeornes, meaning wild beast. So, it's the wildness of a place that makes it a wilderness. The simple presence of people doesn't mean an area isn't "wild." Many ecosystems that have been influenced by people can still be considered "wild." This view includes areas where natural processes happen without much human interference.

Wildlife includes all non-domesticated plants, animals, and other organisms. People have domesticated wild species for their benefit many times, which has had a big impact on the environment. Wildlife can be found in all ecosystems, from deserts to rainforests to even developed urban areas. While the term often means animals untouched by humans, most scientists agree that wildlife worldwide is now affected by human activities.

Ahja jõe ürgorg
A view of wilderness in Estonia

Protecting Our Natural World

Air pollution by industrial chimneys
Before flue-gas desulfurization was installed, the air-polluting emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide.
Walking tree
Amazon rainforest in Colombia. The tropical rainforests of South America contain the largest diversity of species on Earth, including some that have evolved within the past few hundred thousand years.

The idea of a natural environment is central to environmentalism. This is a movement that supports actions and policies to protect nature, or to help nature grow in places where it has been changed. While truly wild places are rare, "wild" nature (like unmanaged forests or wildlife) can still be found in many places once inhabited by humans.

Goals for helping both people and natural systems, often shared by environmental scientists and environmentalists, include:

  • Stopping pollution and harmful chemicals in air, water, soil, and food.
  • Protecting biodiversity and saving endangered species.
  • Using resources like water, land, air, and energy wisely and sustainably.
  • Halting human-caused global warming, which is a form of pollution and a threat to life.
  • Switching from fossil fuels to renewable energy for electricity, heating, and transportation. This helps with pollution, global warming, and sustainability.
  • Moving towards more plant-based diets to help protect biodiversity and fight climate change.
  • Creating nature reserves for recreation and to preserve ecosystems.
  • Managing waste better, including reducing, reusing, recycling, and composting.
  • Reducing excessive consumption and stopping illegal fishing and logging.
  • Slowing and stabilizing human population growth.
  • Reducing the import of old electronics from rich to developing countries.

See also

Kids robot.svg In Spanish: Medio ambiente natural para niños

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