Final answer:
Coal is the major fossil fuel that produces the most pollution and CO₂ per unit of energy, primarily used for electricity generation. Its extraction, transportation, and combustion have significant environmental impacts, contributing to greenhouse gas emissions and other pollutants.
Step-by-step explanation:
Of our major fossil fuels, such as coal, petroleum, and natural gas, coal is the one that produces the most pollution per unit of energy produced. Coal is a naturally occurring nonrenewable solid fossil fuel that, when burned, emits the greatest amounts of pollutants and greenhouse gases, including CO₂. It is primarily used for electricity generation and has a profound impact on the environment, both in its extraction and its usage.
Coal has a higher CO₂ emission compared to other fossil fuels, emitting roughly twice as much CO₂ per unit of delivered energy. This high emission rate is due to coal's lower energy density and its higher mass ratio of CO₂ production. Switching from coal-fired electricity plants to natural gas would result in reduced CO₂ emissions, even though natural gas is also a fossil fuel. These emissions contribute to the greenhouse effect, leading to increased surface temperatures on Earth.
Moreover, the extraction and transportation of coal present their own environmental risks, such as habitat destruction and the potential for accidents leading to spills and leaks. The processing of coal also generates various types of emissions and utilizes significant water resources. It is clear that the production and use of coal as an energy source have both immediate and long-term consequences for our planet.