Natural environment

This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity.

Even acts which seem less extreme, such as building a mud hut or a photovoltaic system in the desert, the modified environment becomes an artificial one.

Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams and the works of mound-building termites are thought of as natural.

Earth science generally recognizes four spheres, the lithosphere, the hydrosphere, the atmosphere and the biosphere[3] as correspondent to rocks, water, air and life respectively.

These major disciplines use physics, chemistry, biology, chronology and mathematics to build a qualitative and quantitative understanding of the principal areas or spheres of Earth.

The Earth's crust or lithosphere, is the outermost solid surface of the planet and is chemically, physically and mechanically different from underlying mantle.

It has been generated greatly by igneous processes in which magma cools and solidifies to form solid rock.

Humans impact the water in different ways such as modifying rivers (through dams and stream channelization), urbanization and deforestation.

The changing vegetation occurs because when trees cannot get adequate water they start to deteriorate, leading to a decreased food supply for the wildlife in an area.

Many natural substances may be present in tiny amounts in an unfiltered air sample, including dust, pollen and spores, sea spray, volcanic ash and meteoroids.

The ozone layer of the Earth's atmosphere plays an important role in reducing the amount of ultraviolet (UV) radiation that reaches the surface.

[17] These scientists are increasingly concerned about the potential long-term effects of global warming on our natural environment and on the planet.

Of particular concern is how climate change and global warming caused by anthropogenic, or human-made releases of greenhouse gases, most notably carbon dioxide, can act interactively and have adverse effects upon the planet, its natural environment and humans' existence.

[18] This warming is also responsible for the extinction of natural habitats, which in turn leads to a reduction in wildlife population.

[19] Efforts have been increasingly focused on the mitigation of greenhouse gases that are causing climatic changes, on developing adaptative strategies to global warming, to assist humans, other animal, and plant species, ecosystems, regions and nations in adjusting to the effects of global warming.

Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate is the term for the average atmospheric conditions over longer periods of time.

Weather systems in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream flow.

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location.

Living organisms undergo metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generations.

[34] Central to the ecosystem concept is the idea that living organisms are continually engaged in a highly interrelated set of relationships with every other element constituting the environment in which they exist.

Eugene Odum, one of the founders of the science of ecology, stated: "Any unit that includes all of the organisms (i.e.: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (i.e.: exchange of materials between living and nonliving parts) within the system is an ecosystem.

"[35] The human ecosystem concept is then grounded in the deconstruction of the human/nature dichotomy, and the emergent premise that all species are ecologically integrated with each other, as well as with the abiotic constituents of their biotope.

This is not universally the case and there is no proven relationship between the species diversity of an ecosystem and its ability to provide goods and services on a sustainable level.

Global biogeochemical cycles are critical to life, most notably those of water, oxygen, carbon, nitrogen and phosphorus.

[36] Wilderness is generally defined as a natural environment on Earth that has not been significantly modified by human activity.

"[37] Wilderness areas and protected parks are considered important for the survival of certain species, ecological studies, conservation, solitude, and recreation.

This way of looking at wilderness includes areas within which natural processes operate without very noticeable human interference.

Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative.

While true wilderness is increasingly rare, wild nature (e.g., unmanaged forests, uncultivated grasslands, wildlife, wildflowers) can be found in many locations previously inhabited by humans.

[48] Specifically in the United States and Arabian countries many native cultures do not recognize the "environment", or see themselves as environmentalists.

Land management has preserved the natural characteristics of Hopetoun Falls , Australia while allowing ample access for visitors.
An image of the Sahara Desert from satellite. It is the world's largest hot desert and third-largest desert after the polar deserts .
A volcanic fissure and lava channel
Earth 's layered structure: (1) inner core; (2) outer core; (3) lower mantle; (4) upper mantle ; (5) lithosphere; (6) crust
Coral reefs have significant marine biodiversity .
Rocky stream in the U.S. state of Hawaii
Lácar Lake , of glacial origin, in the province of Neuquén , Argentina
A swamp area in Everglades National Park , Florida , US
Atmospheric gases scatter blue light more than other wavelengths , creating a blue halo when seen from space.
A view of Earth's troposphere from an airplane
Lightning is an atmospheric discharge of electricity accompanied by thunder , which occurs during thunderstorms and certain other natural conditions. [ 12 ]
The retreat of glaciers since 1850 of Aletsch Glacier in the Swiss Alps (situation in 1979, 1991 and 2002), due to global warming
Another view of the Aletsch Glacier in the Swiss Alps , which because of global warming has been decreasing
Map of world dividing climate zones, largely influenced by latitude. The zones, going from the equator upward (and downward) are Tropical, Dry, Moderate, Continental and Polar. There are subzones within these zones.
Worldwide climate classifications map
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 .
There are many plant species on the planet.
An example of the many animal species on the Earth
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 .
Old-growth forest and a creek on Larch Mountain , in the U.S. state of Oregon
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.
A conifer forest in the Swiss Alps ( National Park )
The Ahklun Mountains and the Togiak Wilderness within the Togiak National Wildlife Refuge in the U.S. state of Alaska
A view of wilderness in Estonia
Before flue-gas desulfurization was installed, the air-polluting emissions from this power plant in New Mexico contained excessive amounts of sulfur dioxide .
Amazon rainforest in Brazil . 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. [ 40 ] [ 41 ]