What kinds of emissions are given off from combustion and what effects do they have on the environment?

CO2 (carbon dioxide)
-Complete combustion of carbon in fuel
-Global warming

CO (carbon monoxide)
-Incomplete combustion of carbon in fuel
-Smog

SO2 (sulphur dioxide)
-Combustion of sulphur in fuel
-Smog, acid rain

NOx (nitrogen oxides)
-By-product of most combustion processes
-Acid rain

N2O (nitrous oxide)
-By-product of some combustion processes
-Global warming

VOCs (volatile organic compounds)
-Leakage and evaporation of liquid fuels (from, e.g., vehicles, fuel tanks, fuel pumps, refineries, solvents from paints)
-Smog

CH4 (methane)
-Principal component of natural gas; leakage from gas wells, pipelines and distribution systems
-Global warming

H2O (water vapour)
-Combustion of hydrogen in fuel
-Localized fog

Particulates (dust, soot, fumes)
-Unburned or partially burned carbon and hydrocarbons; also ash and dirt in fuel
-Smog

Trace elements
-Impurities in fuel
-Potential carcinogens

Halogenated compounds
-Compounds in fuel or combustion air containing halogens (chlorine, fluorine, bromine and iodine)
-Potential carcinogens, global warming