1. Acid Precipitation

2.  Highly acidic precipitation that results from the burning of fossil fuels When fossil fuels are burned, they release SO 2 and NO 2 as byproducts When SO 2 and NO 2 combine with water in the air, they form H 2 SO 4 and HNO 3 (sulfuric acid and nitric acid) which falls in precipitation  Most commonly referred to as acid rain, but there is acid snow and sleet

4. pH  pH measures the acidity or alkalinity of a substance It measures the amount of Hydrogen ions  Scale 1-14 Acid 1-6 Base 8-14 Neutral 7  Water should have a pH of 7  Precipitation is considered acidic if it has a pH less than 5

5. Many buildings and monuments are being destroyed by acid precipitation

6. Effects on Ecosystems  Organisms are adapted to live in their particular environments Most are intolerant to change  They rely on specific climates for survival  Acid precipitation can upset the balance

7. Lakes  When acid precipitation falls into lakes, it raises the acidity of the water  Can kill fish, aquatic plants and other animals  Acid rain leeches aluminum out of soil Al builds up in fish gills, suffocating them

8.  When acid snow melts in spring, it runs into lakes and other bodies of water drastically raising the acidity – acid shock  This can cause entire populations of fish to be wiped out  To fight effects, planes drop lime (base) of lakes to balance pH levels  We cannot spread enough lime to offset the acid damage to all lakes

9. Lime powder being dumped on a lake to neutralize the pH levels

11. Forest  Trees can only withstand a small range of pH levels If the water they take up is too acidic, they will die  Millions of hectares of forest in Northeastern US and Southeastern Canada are dying partly due to acid rain As trees die, the animals that rely on them will too Can destroy entire ecosystems

12. How do we fix this?  Pollutants that cause acid precipitation are nonpoint They may be released hundreds of miles away from where the acid rain falls Ex: most of the acid rain that falls in New England comes from the Midwest and Eastern US  1985 – The Helsinki Convention requires countries to cut SO 2 emissions by 30% over 10 years (US did not sign)

13.  “Global problems can only be solved by global cooperation”  YOUR ASSIGNEMENT: In groups of 2-3 students, come up with a Public Service Announcement (1- 2minutes) on the severity of acid precipitation to present to the class (25points)