News
• http://www.boston.com/news/local/articles/2009/11/05/environmental
_officials_urge_halving_of_phosphorous_levels_in_upper_middle_c
harles_river/
• http://www.boston.com/news/science/articles/2009/11/05/yellowston
e_yields_1200_species_in_1_day_study/
• http://www.boston.com/bostonglobe/editorial_opinion/oped/articles/2
009/11/05/with_tax_break_a_big_carbon_footprint/
• http://www.boston.com/business/articles/2009/11/05/clunkers_milea
ge_impact_queried/
• http://www.cnn.com/2009/TECH/science/11/02/kilimanjaro.glaciers/i
ndex.html
• http://www.boston.com/lifestyle/green/articles/2009/11/02/5000_year
s_later_a_new_warming_warning/
• http://www.kansas.com/news/breaking/story/1033346.html
Stratospheric Ozone
2000 m—0.8 bar
5500 m—0.5 bar
(18,000 feet)
200-300 nm
75% of Mass
below
17 km
>390 nm
Image courtesy of www.aerospaceweb.org
Light
Image courtesy of www.coralnet.ca
Blackbody Radiation
Images removed due to copyright restrictions.
500 nm
Sunlight Spectrum
UVA=320-400 nm
UVB=280-320 nm
UVC=<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
Reactions
Images removed due to copyright restrictions.
Images removed due to copyright restrictions.
Freons completely inert
10-20 year lag in troposphere
65-135 year residence time in stratosphere
Overall ~5% Global Decrease in
Stratospheric Ozone Predicted
Figure by UMB OpenCourseWare.
Slow Leakage
Images removed due to copyright restrictions.
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
Shift in Norms
Images removed due to copyright restrictions.
Antarctic Ozone Depletion (Spring)
Images removed due to copyright restrictions.
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
Images removed due to copyright restrictions.
Regulations
Source: NASA
Solved? By
2050
• Hydro
Halocarbons
(HFCs)
• Single
manufacturer
(Dupont)
• Scientific
consensus
• Simple chemistry
Source: www.sabertec.org
Image courtesy of Leland McInnes, Wikipedia