Air pollution

The lists blow are major air pollutants:
1. Sulphur dioxide (SO₂) - a colourless, odourless air pollutant generated during the
    combustion of fossil fuels, especially coal, and from a variety of industrial processes
2. Nitrogen dioxide (NO₂) - a visible gas  generated from fossil fuel combustion
3. Carbon monoxide (CO) - toxic gas generated from fires, automobiles, and other I
    incomplete combustions of organic matter
4. Photochemical oxidants - such as ozone and peroxyacyl nitrates  produced as a result  of
     atmospheric interactions of NO₂ and sunlight
5. A variety of organic compounds - hydrocarbons emitted into the atmosphere
6. Particulates - small particles of liquids or solids generated from farming, volcanic eruption,
    desertification, industrial processes, and fossil fuel combustion;
7. Hydrogen sulphide (H₂S) - a gas generated by natural processes and by
    petroleum refining and metal smelting
8. Hydrogen fluoride (HF) - an extremely toxic gas released during aluminium production,
    coal gasification and coal burning
9. Various hazardous gases - such as chlorine, pesticides, and solvents released from
    accidents and sewage treatment plants into atmosphere

The greenhouse effect

1. Water vapour, CO₂, methane, CFCs and other gases trap heat in the lower atmosphere;
    thus, they contribute to the greenhouse effect

2. Though the greenhouse effect is a natural atmospheric phenomenon, the anthropogenic
     increases in greenhouse gas accumulations, particularly of CO₂, CFCs, methane, nitrous
     oxides, and ozone, may unnaturally alter global climate

3. Humans add to the atmosphere’s load of greenhouse gases primarily through burning
    fossil fuels and through certain agricultural and forestry practices and industrial
    processes

Global warming - the green house effect, referring to the natural or human-induced increase in the average annual global temperature of earth’s lower  atmosphere.