Climate Control and Ozone Depletion Chapter 20

Core Case Study: Studying a Volcano to Understand Climate Change  June 1991: Mount Pinatubo (Philippines) exploded  Airborne pollutants, deaths, and damage  Affected climate temperature  Climate predictions based on the forecasts of James Hansen of NASA

An Enormous Cloud of Air Pollutants and Ash from Mt. Pinatubo on June 12, 1991

Global Warming and Global Cooling Are Not New (1) What are some natural events that can alter climate? Volcanic emissions Changes in solar input Movement of the continents Impacts by meteors  Over the past 900,000 years Glacial and interglacial periods

Inpact of meteors

Our Climate, Lives, and Economies Depend on the Natural Greenhouse Effect  Without the natural greenhouse effect Cold, uninhabitable earth Four natural greenhouse gases: water vapor carbon dioxide methane nitrous oxide Main sources: agriculture, deforestation, and burning of fossil fuels

Milankovitch cycles

Human Activities Emit Large Quantities of Greenhouses Gases (1)  Countries with the largest CO 2 emissions (as of 2004)  1. ___________________and %_____  2. ___________________and %____  3. ___________________ and % ____  4. ____________________ and %

 The United States and Canada have the highest greenhouse gas emissions per capita (per person)

CLIMAT WEATHER AND CLIMATE What is the difference?

Science: Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers

Human Activities Emit Large Quantities of Greenhouses Gases (2)  Ice core analysis of air pollutants Figure 20-3 page 466  How to measure past temperature changes?  tiny bubbles of atmospheric air trapped in glacier ice.

Page 491 question number two

PRO GLOBAL WARMING 1906–2005: Ave. temp increased about 0.74˚C 1970–2005: Annual greenhouse emissions up 70% Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth Melting of glaciers and floating sea ice Prolonged droughts: increasing Last 100 years: sea levels rose 10–20 cm Hey!!!! C’mon Man  Can’t “cherry pick” datasets.  The increase in carbon dioxide and rate of warming is NOT a linear relationship  There was a major volcanic eruption at the proposed beginning of the current warming period. Mt Pinatubo 1991 followed by an El Nino

The Atmosphere Is Warming Mostly Because of Human Activities (1)  Intergovernmental Panel on Climate Change (IPCC) 90–99% likely that lower atmosphere is warming

CLASSWORK  Page 462 # 1.  Page 462 # 5 Answer in essay (narrative form)

CARBON CYCLE What are carbon sources and carbon sinks?

The oceans hold 50 times more CO 2 that the atmosphere.

Atmospheric Levels of CO 2 and CH 4, Global Temperatures, and Sea Levels

Enhanced Global Warming Could Have Severe Consequences  Tipping point and irreversible climate change  This is going to be depressing.  Worst-case scenarios Ecosystems collapsing Low-lying cities flooded Wildfires in forests Prolonged droughts: grasslands become dust bowls More destructive storms Glaciers shrinking; rivers drying up

Areas of Glacial Ice Melting in Greenland during Summer 1982–2007 Increased

Fig. 19-C (2), p

Fig. 19-8, p. 509 ALABAMA GEORGIA Pensacola Tallahasee Jacksonville Atlantic Ocean Orlando Tampa Gulf of Mexico FLORIDA Fort Meyers Naples Miami Key West

Low-Lying Island Nation: Maldives in the Indian Ocean Total of 1192 Islands

Maldives is the smallest Asian country in both population and land area. With an average ground level of 1.5 metres (4 ft 11 in) above sea level, it is the planet's lowest country. [11] It is also the country with the lowest natural highest point in the world, at 2.4 metres (7 ft 10 in); [11] the Maldives' forecast inundation is a great concern for the Maldivian people. [11]lowest natural highest point [11]

What would a rising sea level do to Myrtle Beach?

Quick review of beach erosion control measures.

Permafrost Is Likely to Melt: Another Dangerous Scenario  Carbon present as CH 4 in permafrost soils and lake bottoms  2004: Arctic Climate Impact Assessment 10–20% of the permafrost might melt this century  Effect on global warming

Fig a, p. 510 Current Boreal Forest RUSSIA ARCTIC TUNDRA Stepped Art 2090–2100 Boreal Forest RUSSIA

Extreme Weather Will Increase in Some Areas  Heat waves and droughts in some areas  Prolonged rains and flooding in other areas  Will storms get worse? More studies needed  Hurricanes Katrina and Rita

Global Warming Is a Major Threat to Biodiversity (1)  Most susceptible ecosystems Coral reefs What is coral bleaching? Polar seas Coastal wetland High-elevation mountaintops Alpine and arctic tundra

Changes in Average Ocean Temperatures, Relative to Coral Bleaching Threshold

Fig , p. 512 Bleaching threshold Temperature (°F) Year

Exploding Populations of Mountain Pine Beetles in British Columbia, Canada

Climate Change Will Shift Areas Where Crops Can Be Grown  Regions of farming may shift Decrease in tropical and subtropical areas Increase in northern latitudes Less productivity; soil not as fertile  Genetically engineered crops more tolerant to drought

Climate Change Will Threaten the Health of Many People  Deaths from heat waves will increase  Deaths from cold weather will decrease  Higher temperatures can cause Increased flooding Increase in some forms of air pollution, more O 3 More insects, microbes, toxic molds, and fungi

Fig , p. 515 SOLUTIONS Global Warming Prevention Cleanup Cut fossil fuel use (especially coal) Remove CO 2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO 2 by planting trees Improve energy efficiency Sequester CO 2 deep underground (with no leaks allowed) Shift to renewable energy resources Transfer energy efficiency and renewable energy technologies to developing countries Sequester CO 2 in soil by using no-till cultivation and taking cropland out of production Reduce deforestation Sequester CO 2 in the deep ocean (with no leaks allowed) Use more sustainable agriculture and forestry Repair leaky natural gas pipelines and facilities Limit urban sprawl Reduce poverty Use animal feeds that reduce CH 4 emissions from cows (belching) Slow population growth

Fig , p. 515 Stepped Art

Fig , p. 516 Oil rig Tanker delivers CO 2 from plant to rig Coal power plant Tree plantation CO 2 is pumped down from rig for disposal in deep ocean or under seafloor sediments Abandoned oil field Switchgrass Crop field CO 2 is pumped underground Spent oil or natural gas reservoir Spent coal bed cavern Deep, saltwater-filled cavern = CO 2 pumping = CO 2 deposit

Should We Use Geo-Engineering Schemes to Help Slow Climate Change? (2)  Remove HCl from seawater Effects on ecology?  Pump up nutrient-rich deep ocean water and cause algal blooms  Re-ice the Arctic  If any of these fixes fail, what about a rebound effect?

How Much Will It Cost to Slow Climate Change?  Short-term costs lower  Local and global economies may be boosted

Governments Can Help Reduce the Threat of Climate Change  Strictly regulate CO 2 and CH 4 as pollutants  Cap-and-trade approach  Increase subsidies to encourage use of energy- efficient technology  Technology transfer

Governments Can Enter into International Climate Negotiations: The Kyoto Protocol  1997: Treaty to slow climate change  The Kyoto Protocol Reduce emissions of CO 2, CH 4, and N 2 O by 2012 to levels of 1990 Trading greenhouse gas emissions among countries Not signed by the U.S. President G.W. Bush’s reasons

We Can Move Beyond the Kyoto Protocol  2004: Stewart and Wiener New treaty needed  Should be led by the U.S.  Include the developing countries  Cap-and-trade emissions program  Set up 10 year goals

Case Study: Reducing Greenhouse Gas Emissions in California  Use of energy-efficient appliances and buildings  Incentives for consumers to use less energy  Why is California suing the federal government?

Some Companies and Schools Are Reducing Their Carbon Footprints (1)  Major global companies reducing greenhouse gas emissions Alcoa DuPont IBM Toyota GE Wal-Mart Fluorescent light bulbs Auxiliary power units on truck fleets

What Can You Do? Reducing CO 2 Emissions

Our Use of Certain Chemicals Threatens the Ozone Layer  Ozone Thinning Seasonal depletion in the stratosphere Antarctica and Arctic  1930: Midgely Discovered the first CFC  Other ozone-depleting chemicals

Global Average Total Ozone Values in the Stratosphere from 1979–2005

Fig , p. 524 Total ozone (Dobson units)

Science Focus: Rowland and Moline—A Scientific Story of Courage and Persistence  Research CFCs are persistent in the atmosphere Rise into the stratosphere over years Break down under high-energy UV radiation Halogens produced accelerate the breakdown of O 3 to O 2 Each CFC molecule can last years  1988: Dupont stopped producing CFCs  1995: Nobel Prize in chemistry 1984: Rowland and Molina CFCs were depleting O 3

Fig. 19-D, p. 525 Sun Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl 3, breaking off a chlorine atom and leaving CFCl 2. UV radiation ClO + O → Cl + O 2 Repeated many times Cl + O 3 → ClO + O 2 Summary of Reactions CFCl 3 + UV → Cl + CFCl 2 Cl F C F Once free, the chlorine atom is off to attack another ozone molecule and begin the cycle again. Cl O O O Ozone O O O O O O A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O 2. O Cl O O O O The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO). O O Cl The chlorine atom attacks an ozone (O 3 ) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O 2 ). C

Fig. 19-E (2), p. 526 Squamous Cell Carcinoma Basal Cell Carcinoma Melanoma Arising from cells in the upper layer of the epidermis, this cancer is also caused by exposure to sunlight or tanning lamps. It is usually curable if treated early. It grows faster than basal cell carcinoma and can spread to other parts of the body (metastasize). The most common skin malignancy usually is caused by excessive exposure to sunlight or tanning lamps. It develops slowly, rarely metastasizes and is nearly 100% curable if diagnosed early and treated properly. This deadliest of skin cancers involves melanocyte cells, which produce pigment. It can develop from a mole or on blemished skin, grows quickly, and can spread to other parts of the body (metastasize).

We Can Reverse Stratospheric Ozone Depletion (1)  Stop producing all ozone-depleting chemicals  60–100 years of recovery of the O 3 layer  1987: Montreal Protocol  1992: Copenhagen Protocol  Ozone protocols: prevention is the key

We Can Reverse Stratospheric Ozone Depletion (2)  Substitutes for CFCs are available  More are being developed  HCFC-22 Substitute chemical May still be causing ozone depletion

 International agreement 8,8  Cold periood G __ ___ ___ ___ ___ ___  Coal gaseous pollutant 6,7  Evidence for past climatological conditions __ __ __ __ __ __ __ S Photochemical ___ ___ ___ ____