Environmental Fundamentals

Study Notes

C.C. Park describes environment as all conditions surrounding humans at a specific time and location.
Douglas and Holland define environment as the sum of external forces and conditions that impact the life, behavior, and development of living organisms.

Physical / Abiotic: Involves non-living components such as the lithosphere, hydrosphere, and atmosphere.
Biological / Biotic: Comprises living organisms in the biosphere, including flora and fauna.
Manmade: Encompasses economic, social, and cultural influences created by humans.

Atmosphere extends up to 300 km above Earth's surface with various components like water vapor, dust, and microorganisms.

Troposphere (0-20 km): Weather occurs here; temperatures range from 15°C to -56°C.
Stratosphere (20-50 km): Horizontal air flow; contains the ozone layer; temperatures range from -56°C to -2°C.
Mesosphere (50-85 km): Temperatures range from -2°C to -92°C; contains Oxygen and Nitric oxide.
Thermosphere (85-500 km): Very high temperatures from -92°C to 1200°C; contains ionized particles.

Lithosphere means "rocky sphere," the solid outer layer of Earth consisting of the core, mantle, and crust.
Core:
- Inner core is solid, composed of iron and nickel, with a density of 13 g/cm³ and a radius of about 1220 km.
- Outer core is liquid, with a density of 11 g/cm³ and a radius of 2250 km.
Mantle: Surrounds the core, divided into upper (670 km radius) and lower mantle (2230 km radius), composed of ultramafic rock.
Asthenosphere: A weaker, hotter part of the upper mantle, stretching 100-200 km.
Crust: Divided into oceanic (5-10 km thick, basalt composition) and continental (20-70 km thick, granite composition).

Includes all of Earth's water, covering 71% of the planet, with water existing as solid, liquid, and gas.
Oceans hold most of the Earth's water, stabilizing surface temperatures and supporting life as a universal solvent.

Forests and wildlife are vital biotic components, comprising various biomes, particularly in India.
Main biomes in India: Tropical humid forest, tropical dry deciduous forest, warm deserts, and dry deserts.
Total forest area in India: 63.73 million hectares (19.39% of land area).