Climate Change and Ozone Loss G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 18 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 18

Past Climate Change Past 900,000 years –Periods of global cooling and warming –100,000 years of thick glacial ice followed by –10,000-12,500 years of warming (ice melts) We have been here for the past 10,000 years Since 1861 the average global temperature has risen 0.6±0.2°C (1.1±0.4°F) (most since 1946)

Average temperature over past 900,000 years Thousands of years ago Average surface temperature (°C) Present

Temperature change over past 22,000 years Years ago Temperature change (°C) 20,00010,0002,0001, Now End of last ice age Agriculture established Average temperature over past 10,000 years = 15°C (59°F)

Temperature change over past 1,000 years Year Temperature change (°C)

Average temperature over past 130 years Year Average surface temperature (°C)

The Natural Greenhouse Effect  Greenhouse effect  Greenhouse gases (Refer to Table 18-1 p. 448) Fig p. 128

Natural Greenhouse Gases Water Vapor –Fairly constant over past 160,000 years Carbon dioxide –Fluctuate between 190 and 290 ppm Earth’s average surface temperature is 15°C (59°F) rather than 8°C (0°F)

GREENHOUSE GASES from HUMAN ACTIVITIES CO 2 CH 4 N 2 O (nitrous oxide) CFC’s Halons (fire extinguishers)

Climate Change and Human Activities  Increased use of fossil fuels  CO 2 and CH 4  Deforestation  CO 2 and N 2 O  Global warming  Melting icecaps and glaciers (albedo)  Coral reef bleaching

Carbon dioxide Temperature change End of last ice age Thousands of years before present Concentration of carbon dioxide in the atmosphere (ppm) –10.0 –7.5 –5.0 – Variation of temperature (˚C) from current level

Carbon dioxide (CO 2 ) Year Parts per million

Methane (CH 4 ) Year Parts per million

Year Parts per million Nitrous oxide (N 2 O)

Canada China Russia Japan India Germany United Kingdom United States Italy France 25.5% 11.2% 6.7% 5.1% 4.1% 3.9% 2.6% 2.5% 2.0% 1.8% Contribution to Global Total (%) CO 2 Emissions

Russia Canada Australia Netherlands Belgium Germany Czech Republic United States United Kingdom France Per Capita Emissions (metric tons) CO 2

Factors Affecting Changes in Earth’s Average Temperature  Changes in solar output  Changes in Earth’s albedo  Moderating effect of oceans  Clouds and water vapor  Air pollution

Less severe winters More precipitation in some dry areas Less precipitation in some wet areas Increased food production in some areas Expanded population and range for some plant and animal species adapted to higher temperatures Some Possible Beneficial Effects of a Warmer Atmosphere for Some Countries

Increased deaths from heat and disease Disruption of food and water supplies Spread of tropical diseases to temperate areas Increased respiratory disease and pollen allergies Increased water pollution from coastal flooding Human Health Rising sea levels Flooding of low-lying islands and coastal cities Flooding of coastal estuaries, wetlands, and coral reefs Beach erosion Disruption of coastal fisheries Contamination of coastal aquifiers with salt water Sea Level and Coastal Areas Changes in forest composition and locations Disappearance of some forests Increased fires from drying Loss of wildlife habitat and species Forests Changes in water supply Decreased water quality Increased drought Increased flooding Water Resources Shifts in food-growing areas Changes in crop yields Increased irrigation demands Increased pests, crop diseases, and weeds in warmer areas Agriculture Extinction of some plant and animal species Loss of habitats Disruption of aquatic life Biodiversity Prolonged heat waves and droughts Increased flooding from more frequent, intense, and heavy rainfall in some areas Weather Extremes Increased deaths More environmental refugees Increased migration Human Population Some Possible Effects of a Warmer World

Antarctica Greenland

Major urban region at riskIslands at risk Sea Level Rise by 2100

PreventionCleanup Cut fossil fuel use (especially coal) Shift from coal to natural gas Transfer energy efficiency and renewable energy technologies to developing countries Improve energy efficiency Shift to renewable energy resources Reduce deforestation Limit urban spawl Slow population growth Remove CO 2 from smokestack and vehicle Emissions Store (sequester CO 2 by planting trees) Sequester CO 2 underground Sequester CO 2 in soil Sequester CO 2 in deep ocean Methods for Slowing Atmospheric Warming During 21 st Century

Removing CO 2 From the Atmosphere Fig p. 467 Tree plantation Coal power plant Tanker delivers CO 2 from plant to rig Oil rig Crop fieldSwitchgrass field Spent oil reservoir is used for CO 2 deposit CO 2 is pumped down to reservoir through abandoned oil field Abandoned oil field CO 2 is pumped down from rig for Deep ocean disposal = CO 2 deposit = CO 2 pumping

Global warming potential (GWP) Field type Conventional tillage No-till cultivation Conservation reserve

N S Waste less water Develop crops that need less water Move hazardous material storage tanks away from coast Prohibit new construction on low- lying coastal areas Stockpile 1 to 5 year supply of key foods Expand existing wildlife reserves toward poles Connect wildlife reserves with corridors Ways to Prepare for the Possible Long-term Effects of Climate Change

CO 2 emissions per mile (pounds per passenger)Type of Transportation 1.6 (0.45 kilograms per kilometer) Sports utility vehicle (1 person, 15 mpg) Average car (1 person, 21.5 mpg) Jet (U.S average occupancy) Mass transit (1/4 full) Economy car (1 person, 40 mpg) Intercity train (U.S average occupancy) Carpool (3 people, 21.5 mpg) Mass transit (3/4 full) Bike or walk0 1.1 (0.31 kilograms per kilometer) 0.97 (0.27 kilograms per kilometer) 0.75 (0.21 kilograms per kilometer) 0.59 (0.71 kilograms per kilometer) 0.45 (0.13 kilograms per kilometer) 0.37 (0.10 kilograms per kilometer) 0.26 (0.07 kilograms per kilometer)

ActionCO 2 Reduction Drive fuel-efficient car, walk, bike, car pool, and use mass transit Use energy-efficient windows Use energy-efficient refrigerator Insulate walls and ceilings Reduce garbage by recycling and reuse Caulk and weatherstrip windows and doors Insulate hot water heater Use compact fluorescent bulbs Set water heater at no higher than (120° F) Wash laundry in warm or cold water Use low-flow shower head 9 kg (20 lbs) per gallon of gasoline saved Up to 4,500 kg (10,000 lbs) per year Up to 1,400 kg (3,000 lbs) per year Up to 900 kg (2,000 lbs) per year 450 kg (1,000 lbs) for 25% less garbage per year Up to 450 kg (1,000 lbs) per year Up to 450 kg (1,000 lbs) per year 230 kg (500 lbs) per year per bulb 230 kg (500 lbs) for each 6° C (10° F) reduction Up to 230 kg (500 lbs) per year for 2 loads a week Up to 140 kg (300 lbs) per year How Can You Reduce Your Annual Emissions of CO 2 ?

Reducing Greenhouse Gas Emissions Rio Earth Summit (1992): developed countries agreed to reduce CO 2 and greenhouse gas emissions to 1990 levels by Rio Earth Summit (1992): developed countries agreed to reduce CO 2 and greenhouse gas emissions to 1990 levels by Kyoto Treaty (1997): requires developed countries to further cut greenhouse gas emissions ; no requirement for developing countries ; allows emission trading ; US has NOT ratified the treaty Kyoto Treaty (1997): requires developed countries to further cut greenhouse gas emissions ; no requirement for developing countries ; allows emission trading ; US has NOT ratified the treaty

Penguins Seals Elephant Weddell Fur Emperor Adélie Petrels Krill concentrations Average minimum extent of summer icepack Average maximum event of winter icepack

HOW IS STRATOSPHERIC OZONE DEPLETED? During the sunless polar winter the circumpolar vortex forms: huge swirling mass of very cold air Water droplets in the air form ice crystals CFC’s adhere to these ice crystals and accumulate When sunlight returns in the spring, the following reaction occurs:

Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl 3, breaking off a chlorine atom and leaving CFCl 2. UV radiation Sun Once free, the chlorine atom is off to attack another ozone molecule and begin the cycle again. A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O 2. The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO). The chlorine atom attacks an ozone (O 3 ) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O 2 ). Cl C F O O O O O O O O O O Summary of Reactions CCl 3 F + UV Cl + CCl 2 F Cl + O 3 ClO + O 2 Cl + O Cl + O 2 Repeated many times

Ozone Depletion Within weeks this typically destroys 40-50% of the ozone over Antarctica. When the vortex breaks up, ozone depleted air masses flow northward over Australia, New Zealand, and South America. This raises dangerous levels of UV in these areas Similar thing happens in Arctic winter.

Seasonal Thinning at the Poles  Ozone thinning (hole)  Polar vortex Fig p. 475

Ozone Depleting Chemicals  Chlorofluorocarbons (CFCs)  Halons  Methyl bromide  Carbon tetrachloride  Methyl chloroform  Hydrogen chloride  Sources of CFCs

Reasons for Concern  Increased incidence and severity of sunburn  Increase in eye cataracts  Increased incidence of skin cancer  Immune system suppression  Increase in acid deposition  Lower crop yields and decline in productivity Refer to Fig p. 476 Refer to Fig p. 476

Human Health Worse sunburn More eye cataracts More skin cancers Immune system suppression Food and Forests Reduced yields for some crops Reduced seafood supplies from reduced phytoplankton Decreased forest productivity for UV-sensitive tree species Wildlife Increased eye cataracts in some species Decreased population of aquatic species sensitive to UV radiation Reduced population of surface phytoplankton Disrupted aquatic food webs from reduced phytoplankton Air Pollution and Materials Increased acid deposition Increased photochemical smog Degradation of outdoor paints and plastics Global Warming Accelerated warming because of decreased ocean uptake of CO 2 from atmosphere by phytoplankton and CFCs acting as greenhouse gases Expected Effects of Decreased Levels of Ozone in the Stratosphere

Solutions: Protecting the Ozone Layer  CFC substitutes  Technofixes : remove Cl and CFC’s from atmosphere  Technofixes : remove Cl and CFC’s from atmosphere  Montreal Protocol: 1987; 36 nations met to develop a treaty to cut CFC emissions, now 177 countries are on board  Montreal Protocol: 1987; 36 nations met to develop a treaty to cut CFC emissions, now 177 countries are on board