Text air pollution

TEXT 4. Harnessing solar energy for usable power

There are many ways to use energy from the sun. The two most important ways to use solar energy are photovoltaic and solar thermal energy. Photovoltaic is much more common on smaller power projects (such as residential solar systems), and solar thermal capture is typically only used for large-scale electricity generation in utility solar systems. In addition to generating electricity, smaller temperature fluctuations from solar thermal projects can be used for heating and cooling. Solar is one of the fastest growing and cheapest energy sources in the world and will continue to expand rapidly in the years to come. As solar cell technology improves every year, the economic benefits of solar power improve and add to the environmental benefits of choosing a clean, renewable energy source.

TEXT 5. Advantages of wind energy

The advantages of wind energy are more obvious than the disadvantages. Key benefits include an unlimited, free, renewable resource (the wind itself), economic value, maintenance costs, and wind harvesting equipment placement. Wind is primarily an unlimited, free and renewable resource. Wind is a natural occurrence and the extraction of the kinetic energy of the wind does not affect currents or wind cycles in any way. Next, harvesting wind energy is a clean and environmentally friendly way to generate electricity. In contrast to other types of power plants, it does not emit air pollutants or greenhouse gases. The wind turbines generate electricity from passing wind without damage. Wind energy is far more environmentally friendly than burning fossil fuels to generate electricity. Currently, the United States, along with other countries, remains dependent on fossil fuels imported from unstable and unreliable nations.

TEXT 6. Advantages and Disadvantages of Afforestation

Afforestation is the settlement of forests on areas that have been forestless for some time, such as previously forested areas that have been converted to pastureland, and the settlement of forests on areas that have not been forested in the past. The term "afforestation" is most often used in connection with discussions of carbon sequestration, the process of removing carbon dioxide from the atmosphere. While afforestation can restore previously forested areas and help remove carbon dioxide, it can have detrimental effects on biodiversity and agricultural profits. Afforestation can restore forests and also help prevent soil erosion and flooding. If done incorrectly, however, afforestation can alter a biome, which can reduce biodiversity.