Topic Test Answers

Environmental risk can be managed by a number of strategies. The first employed is to prevent pollution at its source because this strategy eliminates the need to dispose of waste, restore habitats, or remediate contamination. In situations where pollution prevention is not possible or practical, then other strategies become important. Minimizing the amount of waste generated and properly disposing of the waste that is generated is one strategy, as is avoiding habitat damage.

Seismic waves that move below the surface of the Earth are body waves and are the first to occur. Body waves are composed of two different types of waves, P and S waves. S waves occur after P, and are the most damaging seismic waves. Seismic waves moving along the surface of the Earth are surface waves and are the last type of seismic wave to occur.

Wind, solar, and biomass energy are all forms of renewable energy. Wind and solar energy use do not deplete a natural resource as is the case with coal and oil use. Using renewable resources is a sustainable practice, because it allows for continued energy use. Coal and oil reserves will eventually be depleted beyond the energy demands of the population because they are nonrenewable resources. Wind, solar, and biomass energy, on the other hand, can meet current energy needs and continue to meet the energy needs of the future.

Atmospheric carbon dioxide concentrations are expected to increase, because practices that are responsible for carbon emissions are expected to increase. With an increased demand for energy caused by an increasing population, fossil fuel burning is expected to increase. When fossil fuels burn, carbon dioxide is released into the atmosphere. Additionally, the clearing of forests for agriculture and living space that occurs in response to increasing populations causes a release of carbon dioxide into the atmosphere.

Hydroelectric energy uses the movement of water to spin a turbine and produce electricity. Coal is a fossil fuel that is burned as an energy source, which results in emissions such as carbon dioxide, nitrogen, and sulfur. Coal use is associated with waste products both from the mining process to acquire the coal and also from the actual use of coal itself. Hydroelectric energy does not involve waste, but does pose potential problems to waterways. Coal use is more common than the use of hydroelectric energy.

Fertilizer can have a negative impact on the environment, because of its high nutrient content. When fertilizer enters waterways as runoff, it causes waterways to have an excess of nutrients. This excess of nutrients causes increased algae growth. When these algae decay, they deplete the oxygen in the water, negatively impacting organisms that rely on the oxygen in the water for survival.

Solar and geothermal energy are both considered renewable energy sources. Nuclear energy, on the other hand, is a nonrenewable energy source. Nuclear, solar, and geothermal energy are all low sources of air pollution and do not emit carbon dioxide into the atmosphere. Nuclear and geothermal energy both heat up water to produce electricity. Nuclear energy requires a mining step to obtain the raw material used to produce energy, while solar and geothermal energy do not require mining. Nuclear energy produces nuclear waste, while solar and geothermal energy do not produce a significant amount of waste.