Please take out your Smog City assignment and Bhopal summary for stamping! Please get a laptop as well

Folder Grading Dec., Jan. current events = 10 pts. each Must have stamp, quality summary of at least 150 words, citation, 3 APES concepts Urban Heat Island FRQ, BEV FRQ, Coal FRQ = 10 pts. each Must have stamp, scoring, corrections Have one to turn in? Put it in the inbox now and write “late” or “absent” on it.

Smog City/Acid Rain HW Review In your group, identify any answers you are unsure about and help each other. Team Captain = person who traveled the farthest from Maple Valley over break!

Air Pollution Review! Grab a whiteboard, pen, and tissue

Air Pollution Review 1. What are the two basic equations for the formation of acid rain? 2. What PRIMARY pollutants contribute to photochemical smog formation? NOx, VOCs 3. What SECONDARY pollutants are most present in photochemical smog? Ozone, PANs, Aldehydes

Air Pollution Review 4. “Good” ozone is found in the __________________, while “Bad” ozone is found in the ________________. Stratosphere/troposphere 5. Why is lead bad for you? 6. List 5 primary pollutants and 5 secondary pollutants. 7. Give one negative effect of acid rain and one negative effect of smog.

Top 3 Air Pollution Tragedies 1. Great London Fog of killed 12, Chernobyl Nuclear Explosion- killed “4,000” (really up to 985,000, from cancer) 3. Union Carbide Plant- Methyl isocyanate leak – killed ???? (tens of thousands) Find the two links on my site and read them! You don’t have to write anything down. 1. Top 25 Environmental Disasters 2. Great London Fog

Misconceptions about Ozone There is not an actual “hole” in the ozone – it is an area of substantial thinning – thins different amounts in different areas Thinning has been observed globally, but has been most drastic at the poles Ozone depletion is not the same problem or caused by the same things as global warming

Ozone Depletion Assignment Due next time! Do as a Google doc and share it with me before class. Put your name in the title!

History of ozone thinning 1930’s – 1950’s: Discovery and increased use of CFC’s 1974 – Mario Molina and Sherwood Rowland hypothesized that CFC’s could deplete ozone 1985 – Hole in the ozone was confirmed by NASA and British Antarctica Survey 1987 – Montreal Protocol Early 1990’s – Rate of thinning increases dramatically Mid 1990’s – Substantial thinning detected in Arctic 2000 – highest atmospheric concentrations met

Stratospheric vs. Tropospheric Ozone Troposphere= Bad Secondary pollutant/smog Stratosphere = Good Protects from UV radiation

Types of Ultraviolet Radiation TypeUVAUVBUVC Length/Energy Longest/Least Energetic Intermediate/ Medium Energy Shortest/Very Energetic Pathway to the Earth Not absorbed by ozone/almost all reaches the Earth Absorbed by ozone/reaches the Earth if not stopped by ozone Absorbed by O 2, causes it to break apart/rarely reaches the Earth Damage to Living Things Some DamageHighly DamagingSome Damage UVB reaching the surface of the Earth is really THE problem associated with ozone depletion

Problems associated with UVB Humans Ecosystems Sun Burn Skin cancer Eye cataract Damage to immune System Damages plant leaves Damages algae in the ocean Effects fish, amphibians, mammals Ultimately whole food webs affected – Why?

Natural Formation/Destruction of Ozone with UVB O 3 + UVB  O 2 + O UVB’s energy absorbed to break bond in O 3 Equilibrium is maintained as O3 reforms as quickly as it is broken by UVB

CFC’s disrupt equilibrium CFC – Chloroflurocarbon (CCl 3 F) Were in aerosols, coolants, Styrofoam CFC’s have very long residence times UVB releases chlorines from CFC’s Creates a catalytic chain reaction

Catalytic Chain Reactions CCl 3 F + UVB  3 Cl + CF Cl + O 3  ClO + O 2 ClO + O  Cl + O 2 Cl is the catalyst that is “free” to break apart more Ozone – chain reaction Why is the equilibrium of stratospheric ozone disrupted? More O 2 than O 3 is being created Overall amount of O3 in the atmosphere decreases

Why is thinning worse at the poles? Polar Stratospheric Clouds! Usually atmospheric nitrates can bind some chlorine However, Polar Stratospheric clouds can bind nitrates Nitrates can’t bind chlorine – more thinning!

Montreal Protocol International agreement in 1987 to phase out CFC’s Updated several times, to speed up timetable when extent of damage being caused was realized Developed countries need to help developing countries with technology and money to accomplish phase out Developed countries total phase out Developing countries total phase out – 2015 “Hole” expected to be back to normal by 2050

Alternatives to CFC’s Hydrofluorocarbons (HFC’s) Contain fluorine rather than chlorine, which has a much shorter residence time New cooling technologies using water vapor, hydrocarbons, ammonia