Air Quality Answers

Carbon dioxide (CO2) is one of the principal pollutants released by burning fossil fuels. When carbon dioxide is dissolved in water it forms acid which lowers the pH. In this way the CO2 produced by burning fossil fuels can result in lower ocean pH.

Fossil fuels can be burned anywhere, at any time day or night, meaning there really are no restrictions to their use. Alternative, renewable, energy sources are generally restricted in their use, either geographically or based on weather or time of day. Solar power is only available when the sun is shining, which is only about half the time. Wind power, meanwhile, is dependent upon wind blowing and geothermal power is restricted to volcanically active areas.

Student answers will vary. Possible answers may include discussion of the retention of valuable nutrients, such as nitrogen, in the immediate area of the waste’s production. Composting also prevents organic material from going into landfills where it can decompose anaerobically producing the greenhouse gas methane. Composting also helps break down brown waste, such as paper, cardboard and dead plant material, and return it into the carbon cycle.

In all of these cases the impact of air pollution is not directly related to the toxicity of the gases. Acid rain and ocean acidification occur when pollutant gases react in the environment to form acid. Smog impacts the environment by filtering out sunlight and leaving less available for plants to use. Global warming occurs because greenhouse gases cause earth to retain more of the heat it collects from the sun.

As organic waste decomposes anaerobically in landfills, methane is produced as a byproduct. While methane is a natural gas, it is also a greenhouse gas so it is considered a pollutant.