What is one challenge associated with coal as an energy source?

Choosing environmental pollution during combustion as a challenge associated with coal as an energy source highlights a significant concern in the use of coal for power generation. When coal is burned to produce energy, it emits a variety of harmful pollutants, including carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter.

These emissions contribute to significant environmental issues such as air quality degradation, acid rain, and climate change due to the greenhouse effect caused by elevated CO2 levels. The combustion of coal is not only a major source of greenhouse gases but also releases toxic substances that can impact human health and the environment. This makes environmental pollution a critical challenge in relying on coal as a primary energy source.

In contrast, the other options do not present challenges. High efficiency in energy production suggests that coal can effectively convert a substantial portion of its energy content into usable electricity, which is a positive aspect rather than a challenge. A low carbon footprint would typically indicate an energy source that contributes minimally to greenhouse gas emissions, which is not the case for coal, so this characteristic is misleading. Lastly, easy extraction from the surface is an advantage of surface mining, though it can also lead to environmental degradation; however, it is not a drawback of