Acid rain is a rain or ony ither form o precipitation that is unuisually acidic, meanin that it possesses elevatit levels o hydrogen ions (law pH). It can hae hairmfu effects on plants, aquatic ainimals an infrastructur. Acid rain is caused bi emeessions o sulphur dioxide an nitrogen oxide, which react wi the watter molecules in the atmosphere tae produce acids. Some govrenments hae made efforts syne the 1970s tae reduce the release o sulphur dioxide an nitrogen oxide intae the atmosphere wi positive results. Nitrogen oxides can an aa be produced naiturally bi lichtnin strikes, an sulfur dioxide is produced bi volcanic eruptions. Acid rain haes been shawn tae hae adverse impacts on forests, freshwatters an siles, killin insect an aquatic life-forms, causin pent tae peel, corrosion o steel structures sic as brigs, an watherin o stane biggins an statues as well as haein impacts on human heal.

Processes involved in acid deposeetion (note that anerly SO2 an NOx play a signeeficant role in acid rain).