Coal and natural gas-fired power plants constitute the backbone of global electricity supply; however, they simultaneously represent major direct contributors to environmental pollution and the acceleration of global climate change. While natural gas is often promoted as a cleaner transition fuel compared to coal due to lower combustion-phase carbon intensity, both energy sources impose severe environmental and public health footprints that necessitate rigorous engineering and environmental evaluations to mitigate their impacts.The primary environmental challenges reside in the volume and toxicity of airborne emissions. Coal combustion releases massive quantities of carbon dioxide ($CO_2$), sulfur oxides ($SO_x$), nitrogen oxides ($NO_x$), fine particulate matter ($PM_{2.5}$ and $PM_{10}$), and volatile fly ash containing toxic heavy metals such as mercury. These pollutants drive acid rain formation, cause severe ambient air quality degradation, and elevate respiratory and cardiovascular diseases. Conversely, while natural gas plants emit significantly lower levels of particulates and sulfur oxides, they remain substantial sources of $NO_x$ and suffer from fugitive methane ($CH_4$) leaks across extraction and pipeline transport networks. Methane is a potent greenhouse gas with a global warming potential more than 28 times greater than $CO_2$ over a 100-year timescale, severely eroding the climate advantage of natural gas over coal.To mitigate these severe environmental and climatic impacts, researchers and engineers have developed advanced technological solutions. For coal-fired facilities, implementing clean coal technologies—such as Flue Gas Desulfurization (FGD) wet scrubbers, Electrostatic Precipitators (ESP), and activated carbon injection—effectively captures toxic particulates and acid gases prior to atmospheric discharge. For natural gas facilities, deploying Combined Cycle Gas Turbines (CCGT) alongside Dry Low-NOx (DLN) combustors significantly elevates thermal efficiency while suppressing nitrogen oxide formation. This technological framework is further reinforced by satellite- and drone-based fugitive methane detection and repair (LDAR) networks, complemented by integrating Carbon Capture and Storage (CCS) systems to drastically reduce the overall carbon footprint of fossil-fueled generation.Al-Mustaqbal University – The First Private University in Iraq