Question

how does pollution cause the sky to look black

Answer 1

The pollution of air is caused due to the particulate matter, such as sulfur dioxide, carbon monoxide and other noxious gases emitted by the industries or burning of fossil fuels. Due to presence of these pollutant particles, the scattering of the light occurs in the different way in the atmosphere. This scattered light does not reach to the eyes properly that causes the sky over the horizon to appear brown or gray or black in colour.