OZONE DEPLETION & CLIMATE CHANGE (Ch 20)

ELECTROMAGNETIC SPECTRUM

TYPES OF UV RADIATION UV – A (AGING): Low energy. Thought to contribute to premature aging and wrinkling of the skin and has recently been implicated as a cause of skin cancer. UV – B (BURNING): UV – B (BURNING): Medium energy. UVB is more dangerous than UVA and has been implicated as a major cause of skin cancers, sunburning and cataracts. UV – C: UV – C: High energy. UVC is extremely dangerous but does not reach the earth’s surface due to absorption in the atmosphere. Most of the radiation below 290 nm is absorbed by the ozone in the upper atmosphere. Depletion of this layer increases the amount of UVC reaching ground level.

HEALTH OZONE LAYER DECREASES…. INCREASED UV RADIATION ENTERS

I MPACTS ON ENVIRONMENTAL SYSTEMS  Decreased primary productivity (land & ocean)  Damage to fish/amphibians / mammals  Disrupt food chain  Effects on food crops (beans, wheat, rice, corn)

ATMOSPHRE LAB

Cumulative Graph should look like…

OZONE DEPLETION Ozone- molecule consisting of 3 oxygen atoms  Benefit to humans because it absorbs harmful UV radiation Ozone layer is being depleted because of the addition of chemicals (esp. CFC’s) that break apart the ozone molecule OZONE VIDEOOZONE VIDEO (2:20)

CHEMICAL CLASSES OF OZONE DESTROYERS CHLOROFLOUROCARBONS (CFC'S) CHLOROFLOUROCARBONS (CFC'S) No significant natural sources identified Source: Air conditioning, Aerosol propellants, solvents, styrofoam GREAT longevity  takes 5-7 years for CFC’s to go from ground to upper atm. HALOCARBONS/HALONS (ODS) HALOCARBONS/HALONS (ODS) Highly reactive group 17  Cl, Br, F Sources: Styrofoam, Solvents, Soil Fumigant, Fire Extinguishers

OZONE PHLEMISTRY WKST

O 2 becomes O 3 1)O 2 + UV  ● O + ● O 2) O 2 + ●O  O 3 O 3 becomes O 2 1)O 3 + UV  O 2 + ● O 2) O 3 + ●O  O 2 + O 2 CFCs degrades O 3 into O 2 1)CCl 2 F 2 + UV  ● CClF 2 + ● Cl 2) ●Cl + O 3  ClO● + O 2 NO degrades O 3 into O 2 1) NO + O 3  NO 2 + O 2 A IRPLANES !

OZONE CHEMISTRY for the visual learners

STEP 1: NATURAL FORMATION OF OXYGEN

STEP 2: Natural Formation of Ozone in the STRATOSPHERE

Step 3: Natural Breakdown of Ozone in the STRATOSPHERE

PER CHLORINE ATOM BROKEN OFF BY UV RADIATION FROM CFC’S, ,000 OZONE MOLECULES CAN BE BROKEN DOWN (~900,000 O 3 MOLEUCLES PER CFC!) OZONE CFC Free Radical Chlorine Free Radical Oxygen CLO* STEP 4: CFC’s BREAKING DOWN OZONE (anthropogenic causes)

Ozone over Antarctica ANTARCTIC OZONE HOLEANTARCTIC OZONE HOLE (16 MIN) OZZY OZONEOZZY OZONE (10 MIN)

THOMAS MIDGLEY

CLIMATE CHANGE Long-term change in the earth's climate, especially a change due to an increase in the average atmospheric temperature.

CLIMATE CHANGE - GLOBAL WARMING

GLOBAL WARMING OR CLIMATE CHANGE? GLOBAL WARMING INDICATES THAT THE GLOBAL TEMPERATURE IS INCREASING AND IT IS GETTING HOTTER EVERYWHERE. CLIMATE CHANGE INDICATES THAT CLIMATES ARE SHIFTING AND UNCHARACTERISTIC WEATHER PATTERNS WILL ARISE WHEATHER THAT IS HOTTER OR COOLER, WETTER OR DRYER.

There is absolutely ZERO debate that global temperatures have gone up and down for centuries Question is… are HUMANS the cause of the current shift?

GREENHOUSE EFFECT

Causes of Climate Change Description of what it is Explanation of how it impacts climate (What SCIENTISTS say) Volcanic eruptions When volcanoes erupt, they release dissolved gases (like carbon dioxide, water vapor and sulfur dioxide) into the atmosphere Adds to the build-up of Greenhouse Gases Sunspots More emitted radiation and increased temperatures are found around sunspots More sunspots will increase the amount of heat that stays within the atmosphere. Earth’s orbit There is variation in Earth’s tilt which affects the amount of solar radiation received. Depending on the season, more or less energy is received from the sun. Carbon Dioxide fluctuations As heat is reflected back out into space, carbon dioxide (CO 2 ) absorbs some of the heat. Heat is retained in the atmosphere (not radiated back into space) causing the global temperature to rise.

TRENDS IN ATMOSPHERIC CO 2

Effects of Climate Change 1. HIGHER TEMPERATURES Link: The Nature Conservancy The five hottest years on record have all occurred since CHANGING LANDSCAPES Changing patterns of rain and snow are forcing trees and plants around the world to move toward polar regions and up mountain slopes

ALASKA - Portage Glacier

ARIZONA- Colorado River June 2002Dec 2003

Effects of Climate Change 3. WILDLIFE AT RISK Rising temperatures are changing weather and vegetative patterns across the globe, forcing animal species to migrate to new, cooler areas in order to survive. Experts predict that 1/4 of Earth’s species will be headed for extinction by RISING SEAS Sea level rise from climate change could displace tens of millions of people. Sea levels could continue to rise between 4 inches and 36 inches over the next 100 years.

Effects of Climate Change 5. INCREASED RISK OF DROUGHT, FIRE & FLOODS Massive land erosion is one result of overgrazing & drought in Kenya 6. STRONGER STORMS & HURRICANES Hurricanes and tropical storms to become more intense — lasting longer, unleashing stronger winds, and causing more damage to coastal ecosystems

Effects of Climate Change 7. MORE HEAT RELATED ILLNESS & DISEASE As temperatures rise, so do the risks of heat-related illness and even death for the most vulnerable human populations. Increase the spread of infectious diseases. 8. ECONOMIC LOSSES Climate change could cost between 5 and 20 percent of the annual global gross domestic product. Declining crop yields could put hundreds of thousands of people at risk for starvation.

Effects of Climate Change 9. OCEAN ACIDIFICATION As temperatures rise, so does the amount of carbon dioxide in the ocean causing acidic water. 10. EL NINO & LA NINA Weather patterns in the Pacific Ocean change causing an increased frequency of bad weather events to occur around the world.

Global Atmospheric Concentration of CO 2

CLIMATE CHANGE CONTROVERSY? NOT FOR SCIENTISTS!

The way I see it…. My personal opinion

YOU WHAT CAN YOU DO TO HELP SLOW DOWN GLOBAL CLIMATE CHANGE?

Neil deGrasse Tyson, Astronomer makes a very good point...

Temperature (Northern Hemisphere) CO 2 Concentrations 1000 Years of CO 2 & Global Warming Degree Celsius Increase Parts Per Million Year

2007 Goal: Reductions in CO 2 Per Year Billions of Metric Tons Carbon

2007 Reductions in CO 2 Per Year Gigaton Carbon Produce electricity efficiently Use electricity efficiently Vehicle efficiency Solar and Wind Power Biofuels Carbon capture and storage Billions of Metric Tons Carbon Our Goal

How ozone is destroyed by CFCs