News• http://www.boston.com/news/local/articles/2009/11/05/environmenta

l_officials_urge_halving_of_phosphorous_levels_in_upper_middle_charles_river/

• http://www.boston.com/news/science/articles/2009/11/05/yellowstone_yields_1200_species_in_1_day_study/

• http://www.boston.com/bostonglobe/editorial_opinion/oped/articles/2009/11/05/with_tax_break_a_big_carbon_footprint/

• http://www.boston.com/business/articles/2009/11/05/clunkers_mileage_impact_queried/

• http://www.cnn.com/2009/TECH/science/11/02/kilimanjaro.glaciers/index.html

• http://www.boston.com/lifestyle/green/articles/2009/11/02/5000_years_later_a_new_warming_warning/

• http://www.kansas.com/news/breaking/story/1033346.html

Stratospheric Ozone

75% of Mass below17 km

>390 nm

200-300 nm

2000 m—0.8 bar5500 m—0.5 bar(18,000 feet)

Image courtesy of www.aerospaceweb.org

Light

Image courtesy of www.coralnet.ca

Sunlight Spectrum

UVA=320-400 nmUVB=280-320 nmUVC=<280 nm

Stratospheric Vs. Tropospheric Ozone

Image courtesy of www.aerospaceweb.org

Ozone Depletion

• O2 + hv O + O

• O + O2 O3

• O3 + hv (<290 nm) O2 + O

• O3 + Cl O2 + ClO

• ClO + O O2 + Cl

• O3 + O 2O2

• Cl can catalyze destruction of O3 100,000 times

Overall ~5% Global Decrease in Stratospheric Ozone Predicted

Figure by UMB OpenCourseWare.

Cancer Causing DNA Breakage due to UV rays

Image courtesy of www.assh.org

Melanoma

Image courtesy of visualsonline.cancer.gov

Carcinomas

Image courtesy of www.seattlecca.org

Antarctic Ozone Hole

5% loss in O3 500% increase at 287 nm

Image courtesy of NOAA Research

Polar Vortex, Spring

Image courtesy of NASA Goddard Space Flight Center

Polar Stratospheric Clouds (PSC)

• Antarctic Spring

• Polar Vortex

• Stratospheric clouds made of ice (nitric acid)

• Sunlight initiate reactions

• Heterogeneous chemistry (on particles)

Image courtesy of NASA Goddard Space Flight Center

Index Card

• How can we solve this problem?

Solutions

US Clean Air Act: Venting of CFC/HCFC Refrigerants

Illegal July1, 1992

Regulations

Source: NASA

Solved? By 2050

• Hydro Halocarbons (HFCs)

• Single manufacturer (Dupont)

• Scientific consensus

• Simple chemistrySource: www.sabertec.org

Image courtesy of Leland McInnes, Wikipedia