Environment is a term with wide scope and encompasses all conditions that surround any organism or a group of organisms. It includes the external circumstances, physical conditions, influences, conditions, resources which interact with an organism and influence its growth and development. Hence, our Natural environment includes all living and non-living things that occur naturally on the planet. Built environment, as the name suggests include the constructed surroundings that create the support system for human activity to form personal spaces as well as large civic surroundings.

Natural environment:

1. It includes all landscape area that functions as a natural system on its own without any interference of human beings. This includes animals, rocks, plants, and wilderness (most of it like unmanaged forests, wildlife and so on) etc.
2. It also includes universally existing natural resources and other physical processes that exist on their own and do not originate from any sort of human activity. These include climate, air, water, radiation, energy etc.
3. Natural aspects occurring within areas that are largely influenced by man. For example, birds in urban gardens etc. are considered a part of the natural environment.
4. A geographical area can also be considered as natural environment, if human impact on it is under a limited level.

Built Environment:

1. All the buildings, architecture, artificial surroundings that are heavily influenced by man, and do not exist naturally.
2. They are now so extensive that they act as organisms in terms of resources that they consume, waste disposal, facilitating productive enterprises etc.

Challenges

Built environment, is considered to be as opposed to the natural environment as there is considerable impact of built environment on natural environment due its existence in contrast with the same.

Concern for environment has often been viewed as a luxury and has more often than not been limited to few perceptions. It is here, that understanding various aspects of environment and the need for us to take responsible steps further comes in. Natural as well as human made environmental resources form our support systems for sustenance and are a key towards social and economic development. This includes forest cover, fresh water, air, agro- ecosystems, marine resources, grasslands etc. Environmentalism largely deals with not only the preservation of natural environment but also restoration and improvement. But, some include improvement of quality of life, quality of growth and protection of regional commons as an essential objective of environmentalism in order to reduce affects of the built environment. Environmentalism is largely associated with greening, resource management, environmental responsibility, waste minimization and overall environmental management.

Environmental Concerns:

Some of the common environment issues that environmentalism deals with:

1. Climate change
   • Global warming
   • Fossil fuels
   • Sea level rise
   • Effects of the automobile on societies
   • Natural Disasters
2. Conservation (Flora and fauna)
   • Invasive species
   • Species extinction
   • Pollinator decline
   • Coral bleaching
   • Bio Diversity
3. Dams
   • Environmental impacts of dams
4. Energy
   • Energy conservation
5. Genetic engineering
6. Intensive farming
   • Overgrazing
   • Irrigation
7. Land degradation
   • Land pollution
   • Desertification
8. Soil
   • Soil conservation
   • Soil erosion
   • Soil contamination
   • Soil salination
9. Nanotechnology
   • Nanotoxicology
   • Nanopollution
10. Nuclear issues
    • Nuclear fallout
    • Nuclear meltdown
    • Nuclear power
11. Ozone depletion
    • Overpopulation
12. Pollution
    • Air pollution
    • Light pollution
    • Noisepollution
    • Thermal pollution
    • Water pollution
    • Drinking water
    • Eutrophication
    • Water crisis
    • Oil spills
13. Resource depletion
    • Fishing
    • Environmental effects of fishing
    • Overfishing
    • Bottom trawling
    • Logging
    • Illegal logging
    • Deforestation
    • Mining
    • Acid mine drainage
14. Toxic waste
    • Dioxin
    • Chlorofluorocarbons
    • Heavy metals
    • Herbicides
    • Pesticides
15. Urban sprawl
16. Waste
    • Waste types
    • Waste management
    • The waste hierarchy
    • Waste legislation
    • Waste collection
    • Waste treatment technologies

The principle of conservation and the belief that nature too has a right has become the basis of modern environmentalism. Commonly, it is a broad social, scientific, political as well philosophical movement that enumerates various actions and policies in protecting our natural environment like reduction and control of man-made pollution, conservation and sustainable use of resources etc. The movement is focused at ecology, human rights, health and has been incorporated in religion as well.