1. The branch on the left is from a tree in the Black Forest in Germany.
  2. Learning objectives • What is acid rain? • How is it formed? • What effects does it have on people and the environment? • Where are the effects evident? • How can the effects be reduced?
  3. The Formation of Acid Rain The rest reacts with sunlight and ozone in the atmosphere; nitric (HNO3), and sulphuric acid (H2SO4) are produced Some falls back to Burn fossil fuels in Earth close to the source as dry It is dissolved in the Transport, Industry, moisture in the particles, gas and Homes, power stations atmosphere making aerosols NO2 SO (NOx and SO2) 2 _ 2H+ and SO42 (dry H2O and can be carried large deposition) distances before falling as rain or snow (wet deposition) _ _ H+ NO3 SO42 Gas, Oil, Coal TRANSBOUNDARY POLLUTION
  4. The main pollutants which cause acid rain are… Sulphur dioxide – released from coal fired power stations Nitrous oxides - released from gas fired and coal fired power stations and car exhaust emissions
  5. Acid Deposition Acid deposition involves the deposition of both wet and dry acidic components
  6. Dry Deposition • The chemical pollutants may become incorporated into dust or smoke and fall to the ground through dry deposition but they combine with any moisture on the surface of buildings, trees etc to form an acid.
  7. Wet Deposition • The polluting gases react with oxygen in the atmosphere to produce dilute forms of sulphuric acid and nitric acid. These acids are taken into solution by cloud and rain droplets and then move through the hydrological cycle. • This wet deposition can travel a long way from the source of pollution
  8. The effects…
  9. The effects … Chemical reactions The chemical release toxic weathering of metals, particularly buildings, aluminium into statues and solution stone objects. Soils become more acidic. Unless lime is added the quality of the crops is reduced Acid rain destroys tree roots. The Acids activate trees are aluminium from then more the soil which likely to leaches into suffer from water and fish drought and die. Drinking disease water is contaminated
  10. Why is acid rain an international issue?
  11. Transboundary deposition • The countries that are producing the majority of the Pollution that causes acid rain (Britain, Germany, USA) aren’t that badly affected by acid rain. • Instead, the wind direction means the acid rain falls elsewhere (in Europe this affect Scandinavia; USA affects Canada).
  12. How might the effects of acid rain be reduced? Add lime to lakes affected Burning coal which by acidification But … contains less sulphur It costs Tales a long Remove sulphur time to phase from coal before out thermal it is used power stations Switch to alternative energy supplies Impact on coal mining Remove sulphur from industry as waste gases after it is demand falls used (Flue gas desulphurisation) International Energy conservation agreements to methods Using unleaded petrol reduce sulphur dioxide emissions

Acid Rain

Effects on Plants

• Effect on plants is the leaves turn yellow.
• Plants wouldn’t be able to make food: Photosynthesis doesn’t work.
• Plants will die.

What is Acid Rain?

• Rain with a PH below normal
• Ph scale: 1-14. 7 is in the middle: Strong bases are 14’s. Lemon juice and battery acid are 2/1, respectively.

Sources of acid rain

• Burning gas, oil, and coal.
• Burning those gives off NO2 and SO2’s, mixes with water in the clouds, then the wind moves it. When they reach, nitric acid and sulphuric acid are produced.
• Two types: Dry Deposition and Wet Deposition. Dry means it doesn’t mix with water, it just falls down to earth. Wet deposition is our acid rain. It mixes with the water to make either rain or snow.

Why is it an international issue?

• Acid rain is both an international and state issue.
• Three biggest countries for fault are USA, Great Britain, and China. Germany also
• We aren’t very affected, but those to the east of us are.


• Crop production falls.
• Acid in the rivers and lakes kills fish.
• Buildings and stone erode
• Huge stands of trees die.