Thermal pollution is a type of pollution that occurs when there is a sudden change in temperature in a natural body of water, such as an ocean, lake, river, or pond, due to human influence. It can be caused by both natural events and human activities, but the most common cause is the discharge of wastewater used for industrial cooling. Thermal pollution can also happen when something affects a body of waters ability to cool off naturally. The following are some key points about thermal pollution:
Causes:
- Industrial machinery and power plants are big contributors to thermal pollution.
- Urban runoff, stormwater discharged to surface waters from rooftops, roads, and parking lots, and reservoirs can also be a source of thermal pollution.
- Soil erosion causes bodies of water to be more exposed to sunlight, thus increasing their temperature.
- Natural causes of thermal pollution include heat from wildfires, volcanoes, and underwater thermal vents, as well as lightning strikes.
Effects:
- Thermal pollution harms water-dwelling organisms, as sudden changes in water temperature can decrease oxygen supply and affect ecosystem composition.
- Fish and other organisms adapted to a particular temperature range can be killed by an abrupt change in water temperature, known as "thermal shock".
- Thermal pollution can also cause algal blooms to become worse, as sewage and agricultural waste are often high in nutrients.
- Thermal pollution can increase surface temperatures in the summer, leading to releases of warm air into the atmosphere and contributing to global warming.
Solutions:
- The best way to address thermal pollution is to get rid of once-through water cooling systems.
- Cooling towers can be used to cool water before it is returned to the natural environment.
- Natural vegetation can be planted along the banks of water bodies to provide shade and reduce the amount of sunlight that reaches the water.
- Regulations can be put in place to limit the amount of water that can be taken from natural sources for industrial cooling.
