Emissions of pollutants and gases from human activities have many negative effects on the local, regional and global environment. Greenhouse gas (GHG) emissions exacerbate the natural greenhouse effect, leading to temperature changes and other consequences for the earth's climate. Air pollutants such as sulphur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOC) contribute to regional and local air pollution, and affect human health and ecosystems.