Title: Natural environment - Wikipedia
Headings: Natural environment
Natural environment
Contents
Composition
Geological activity
Water on Earth
Oceans
Rivers
Lakes
Ponds
Human impact on water
Atmosphere, climate and weather
Layers of the atmosphere
Principal layers
Other layers
Effects of global warming
Climate
Weather
Life
Ecosystems
Main article: Ecosystem
Biomes
Biogeochemical cycles
Wilderness
Challenges
Criticism
See also
References
Further reading
External links

Content: 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 encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to the Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components: Complete ecological units that function as natural systems without massive civilized human intervention, including all vegetation, microorganisms, soil, rocks, atmosphere, and natural phenomena that occur within their boundaries and their nature. Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water, and climate, as well as energy, radiation, electric charge, and magnetism, not originating from civilized human actions. In contrast to the natural environment is the built environment. In such areas where humans have fundamentally transformed landscapes such as urban settings and agricultural land conversion, the natural environment is greatly changed into a simplified human environment.