Environment

The term "environment" means the surroundings of a living creature. It can also refer to all the factors of the external world that affect biological and social activities. There are abiotic (nonliving) environmental factors such as sunlight, air, and water. There are also biotic (living or recently living) environmental factors such as plants, animal predators, and food. The total environment of an organism is the sum total of the biotic and abiotic environments. The study of the relationships between living creatures and their environments is called ecology.

A human's abiotic environment includes things such as weather (sun-light, wind, air temperature) and items which give protection from the weather (clothes or houses). Other abiotic factors are the soil and water, and chemicals in the soil and water. A human's biotic environment includes things such as food (plants and animals), other humans, animals, trees, and grasses. The biotic environment also includes how living creatures interact with each other and their abiotic environments. Therefore, a human's biotic environment also consists of social or cultural surroundings. Humans learn from each other how to behave in socially acceptable ways. They also pass along knowledge about language, science, and art.

The major components of Earth's physical environment are the atmosphere, climate and weather, land, and bodies of water such as lakes, rivers, and oceans. The term "environment" is commonly associated with the impact that humans have made on the natural world. Increasing human population and industrial activities have led to problems associated with the pollution of air, water, and soil. Pollution has a negative impact on humans in terms of health and quality of life, as well as on other animals and plants.

Human activities such as the dumping of industrial wastewater and poorly treated sewage water have led to the pollution of fresh and salt water. Groundwater, water beneath the land surface that often serves as drinking water for humans, has also been negatively affected. Accidental oil spills from ships and untreated storm-water runoff from urban and agricultural areas also degrade bodies of water.

Air pollution results from human activities such as burning fossil fuels (oil, coal, and gasoline) to create electricity and power automobiles, and manufacturing industrial products such as chemicals and plastic. Burning fossil fuels releases carbon dioxide into the atmosphere, adding billions of extra tons of carbon to the natural carbon cycle. Deforestation and poor soil management also add carbon. Most scientists believe that the increased carbon dioxide in the atmosphere contributes to the potentially devastating warming of the global climate, the so-called "greenhouse effect." Another human impact on the atmosphere has been depletion of the ozone layer. The ozone layer helps filter ultraviolet light and protects Earth's surface from harmful doses of radiation. Many scientists believe that chlorofluoro-carbons used as coolants in air conditioners and refrigeration units destroy ozone when released into the atmosphere.

Land pollution is caused by poor agricultural practices, mining for coal and minerals, and dumping industrial and urban wastes. The widespread usage of pesticides has led to pollution of both soils and bodies of water.

As more and more environmental problems become evident, humans will have to assess their activities and their impact on the natural world.