5 What harms the ozone layer? CFCs = chlorofluorocarbonsLarge, man-made molecules with chlorine in them.CFCs were used in many aerosols, refrigeration units, air conditioners.UV radiation knocks the chlorine out of the molecule, where it then is able to react with ozone, destroying it.
6 The ozone hole YouTube - The Earth's Ozone Hole from 1979-2007 During the Antarctic winter, June-August, cold winds circle the AntarcticAir above Antarctica is very cold then.Chlorine split off from CFCs. Then, when sunlight returns in September-November, the sun’s rays split chorine molecules into chlorine atoms, which destroy ozone.
7 Impact of ozone holeLower ozone allows more UV-B radiation to reach the ground.This radiation can damage DNA in humans and other organisms.UV radiation can kill phytoplanktonUV radiation can interfere with photosynthesis
8 Protecting stratospheric ozone 1987 – nations met in Canada and agreed to limit their production of CFCs (Montreal Protocol).
10 Particulate pollution What is it?Small particles in the atmosphereMade of sulfuric and nitric acid, organic chemicals, metals, soil, and dust particlesTwo sizesLarger: 2.5 – 10 micrometers called PM10Smaller: < 2.5 micrometers called PM2.5
11 Particulate matterPM10: coarse particles, near roadways and dusty placesPM2.5: emitted by forest fires, cars, or form from gases emitted.