Thermal Pollution: Causes

Thermal Pollution: Causes

            According to the Encyclopedia of Earth, thermal pollution is the act of altering the temperature of a body of water, such as a river, lake or ocean setting.  Thermal pollution is chiefly discussed in the sense of raising the water temperature but can also be referred to as releasing cold reservoir water into a warmer aquatic environment.  This concept is primarily caused by wastewater released from power generation plants into surrounding bodies of water, but other sources also contribute to thermal pollution.

-      Nuclear Power Plants: These plants are usually constructed near large bodies of water in which the plants could extract water to cool down the systems.  After the water runs through the plant, the water is recycled and returned to the reservoirs of water.  The temperature remains significantly high and has severe ecological impacts, such as decreasing dissolved oxygen levels.

-      Urban Runoff: Runoff contributes to thermal pollution as water from smaller streams passes over hot surfaces (i.e. parking lots) and enters a variety of aquatic environments. 

-      Soil Erosion: Soil erosion on the shore results in muddy waters.  The darker color increases light absorption, which causes the water temperature to rise.

-      Deforestation of Shoreline: Deforestation further contributes to thermal pollution by encouraging soil erosion and increasing the amount of light that shines on the water.  The increase in light rays causes an increase in water temperature.    

-      Natural Causes: Geothermal and volcanic activity underneath the ocean surface is known to cause thermal pollution. Lightning strikes and a ground flow of lava also introduce excessive amounts of heat to water reservoirs, while the flow of warmer currents into colder environments fosters thermal pollution as well. The drastic temperature increase resulting from these natural causes can damage fish eggs and larvae thus disrupting the food chain balance within the ecosystem.

Thermal pollution is defined as the discharge of water into aquatic biomes that causes an unfavorable change in temperature.  Whether this change is caused by natural or man-made sources, thermal pollution severely affects the organisms living in the regions where the pollution is present.