Introduction to Fossil Fuels | Understand Energy Learning Hub
Combustion and Post‑Combustion. Burning fossil fuels for electricity, heat, and transportation is one of the most polluting human activities, releasing greenhouse gases (CO 2), air pollutants (NO x and SO 2), and plants also use water for cooling. After combustion, pollutants such as coal ash require management and pollutants can be removed from the smokestack.