Final answer:
Competition from alternative energy sources, environmental regulations, and environmental impacts make coal mining uneconomic.
Step-by-step explanation:
The geological factors that make coal mining uneconomic include competition from cheaper alternative energy sources such as natural gas, solar, and wind. Environmental regulations discouraging the use of high-sulfur coal also contribute. Additionally, coal mining has numerous environmental impacts, including the emission of pollutants like sulfur dioxide, nitrogen oxide, and mercury, as well as the production of carbon dioxide and ash. Some mining practices negatively impact ecosystems, water quality, and landscapes.