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The environment is our physical surroundings. This includes both human (man-made), social and physical (natural) features. Natural features include soil, the atmosphere, vegetation and wildlife. Human features include housing, transport and industry. Social features include things such as culture, language and political systems.
Geographers are concerned about human action in the environment. Human interference with the environment causes problems such as soil erosion, global warming and acid rain.
You may ask how we as individuals can have an impact on the environment. Our actions can help to increase and decrease the problems highlighted above. For example turning off lights that are not being used helps to reduce global warming.