AYY LMAO OZONE WOOOOOSH What is ozone? - and why do we need it? • Ozone molecules contain 3 oxygen atoms • It's present naturally in the atmosphere • It protects us from dangerous radiation from the sun • The ozone layer is essential for life on earth • Without an ozone layer there would also be several negative effects on our health WHY DID THE OZONE LAYER START TO DISAPPEAR? • Before the Montreal protocol came in effect we used a lot of CFC CFC was used to many different things It's the chlorine in CFC that reacts with ozone cousing it to break down The ozone layer breaks down every year even without the help of man DU IN NORRKÖPING, SWEDEN 1990 1995 2000 2005 2011 500 400 300 200 100 0 Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec THE MONTREAL PROTOCOL • DU is short for dobson unit • Dobson unit measures density of a gas • 300 DU is a 3mm layer of ozone • The ozone level is expected to rise first in 2015 due to the Montreal Protocol • The protocol entered into force on January 1, 1989 • It's purpose was to limit the use of substances that harms the ozone levels HOW DO WE MEASURE OZONE? • G.M.B. Dobson introduced the world to the ozone spectrophotometer in 1924 That's why the unit for is called DU, or Dobson Units It provided a way of measuring ozone It compares the intesity of UV-radiation in different wavelengths THE WEATHERS EFFECT ON OZONE • Ozone is created by UV-radiation splitting oxygen molecules • The oxygen atom reacts with a oxygen molecule and ozone is created • For the most part this process takes place in the stratosphere • The angle of the incoming UV-radiation is important ENVIRONMENTAL EFFECTS OF A LOWERED OZONE LEVEL • Every year a big ozone hole appears over Antarctica Due to the hole the temperature rises causing more ice to melt • The melting ice raises the sealevel • A raised sealevel can lead to several countries just in Europe being under the new sealevel