Climate Control

1. Climate Control Chapter 19

2. An Enormous Cloud of Air Pollutants and Ash from Mt. Pinatubo • June 1991: Mount Pinatubo (Philippines) exploded • Airborne pollutants, deaths, and damage • Affected climate temperature • James Hansen(NASA) cooled the temp of the earth by )0.5* over a 19th month period. Then the earth would warm

3. Earth’s Future Temperature and Climate Change • The overwhelming scientific consensus is that the earth’s atmosphere is warming rapidly, mostly because of human activities, and that this will lead to significant climate change during this century.

4. Global Warming and Global Cooling Are Not New • Over the past 4.7 billion years the climate has been altered by • Volcanic emissions • Changes in solar input • Movement of the continents • Impacts by meteors • Over the past 900,000 years • Glacial and interglacial periods

5. Global Warming and Global Cooling Are Not New • Over the past 10,000 years • Interglacial period, fairly stable climate and steady average global surface temperature • Over the past 1,000 years • Temperature stable but began to rise during the last century when forests cleared, fossil fuel burned • Over the past 100 years • Temperature changes mostly since 1975

6. Different techniques…….. • Analysis of radioisotopes in rocks and fossils • Plankton and radioisotopes in ocean sediments • Tiny bubbles of ancient air found in ice cores from glaciers • Temperature measurements taken at different depths from bore holes drilled deep into the earth’s surface • Pollen from lake/bog bottoms • Tree rings • Historical records - 1861

7. Estimated Changes in the Average Global Temperature of the Atmosphere

8. Our Climate, Lives, Economies Depend on the Natural Greenhouse Effect ( Arrhenius) • Without the natural greenhouse effect, warms the earth’s lower atmosphere and surface. • Solar energy absorbed by the earth radiates into the atmosphere as infrared radiation(heat) • 1% of earth’s lower atmosphere is compressed of greenhouse gases- water vapor, carbon dioxide, methane, and nitrous oxide • Cold, uninhabitable earth

9. Human Activities Emit Large Quantities of Greenhouses Gases • Since the Industrial Revolution (275 years ago) • CO2, CH4, and N2O emissions higher • Main sources: agriculture, deforestation, and burning of fossil fuels • Correlation of rising CO2 and CH4 with rising global temperatures, during past 400,000 years • Countries with the largest CO2 emissions- US, China, EU-27 contries, Indonesia, Russia, Japan, India

10. Human Activities Emit Large Quantities of Greenhouses Gases • Per capita emissions of CO2 Scientific and economic studies • 2007: Field and Marland 560 ppm by 2050 – 1390 by 2100 Tipping point 450 ppm • 2008: Aufhammer and Carson • China’s CO2 emission growth may be underestimated • Ice core analysis – 60% of methane emissions • human impact – landfills, raising live stock, extracting fossil fuels • Nitrous oxide – nitrogen fertilizers

11. Atmospheric Levels of CO2 and CH4, Global Temperatures, and Sea Levels

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

13. Alaska’s Muir Glacier • Al Gore and the IPCC : Nobel Peace Prize • Natural and human-influenced factors could have an effect on temperature changes

14. The Big Melt: Some of the Floating Sea Ice in the Arctic Sea Drop in average cover of summer arctic ice

15. Scientific Consensus about Future Temperature Change? • Mathematical models used for predictions • Global warming: rapid rate • Human factors are the major cause of temperature rise since 1950 • Human factors will become a greater risk factor

16. Model of Some Major Processes That Interact to Determine Climate

17. Comparison of Measured Temperature from 1860–2007 and Projected Changes

18. Is a Hotter Sun the Culprit? • Since 1975- satellite and balloon measurements • Troposphere has warmed • Stratosphere has cooled • Scientists have concluded that the rapid rise in global mean temperature could not be the result of increased solar output

19. Can the Oceans Save Us? • Solubility of CO2 in ocean water – removes 25-30% of the carbon dioxide pumped into the lower atmosphere by human activities. Some of it converted to insoluble carbonate salts that are buried in the bottom sediments • Warmer oceans • Solubility decreases increases atmospheric CO2 • Coral reefs destroyed • Increased acidity –less carbon dioxide absorbed, increases growth of some algae • drop in populations of phytoplankton, • Antarctica’s Southern Ocean and the North Atlantic Ocean –decrease in carbon dioxide uptake

20. There Is Uncertainty about the Effects of Cloud Cover on Global Warming • Warmer temperatures create more clouds by increased evaporation of surface water • Thick, light-colored low altitude clouds: decrease surface temperature • Thin, cirrus clouds at high altitudes: increase surface temperature • Effect of jet contrails on climate temperature – they expand and turn into cirrus clouds that release heat into the upper troposphere

21. Outdoor Air Pollution Can Temporarily Slow Global Warming • Aerosol and soot pollutants • light colored sulfate particles, reflect sunlight and cool atmosphere • sulfate particles also cool the lower atmosphere by forming condensation nuclei that form cooling clouds

22. Some Possible Effects of a Warmer Atmosphere…………… • The projected rapid change in the atmosphere's temperature during this century is very likely to • Increase drought and flooding, • shift areas where food can be grown, • raise sea levels, • result in intense heat waves, • cause the premature extinction of many species.

23. Enhanced Global Warming Could Have Severe Consequences • Very rapid, global change in climate – projected rapid increase in average temperature in the lower atmosphere • 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

24. Stepped Art Fig. 19-7, p. 507

25. Severe Drought Is Increasing from 15-30% • less moisture in the soil – NPP will decrease • stream flows and available water will decline • Biodiversity will decrease • growth of plants/trees will slow • forest and grassland fires will increase • some lakes/seas will shrink and disappear, rivers will fail to reach the sea • 1-3 billion people will face water shortage • dry climate biomes will increase – savannas, chapparal,deserts

26. Ice and Snow Are Melting • global warming be worse in the polar regions – exposure of darker land, absorb more solar radiation • floating sea ice disappearing – could affect the average rate of precipitation in certain areas • Mountain glaciers affected by • Average snowfall, adds to mass in winter • Average warm temperatures- apur their melting during the summer

27. Ice and Snow Are Melting • Europe’s Alps • Glaciers are disappearing • South America • Glaciers are disappearing • Greenland • Warmer temperatures Areas of Glacial Ice Melting in Greenland

28. Melting Ice in Greenland • Largest island: 80% composed of glaciers • 10% of the world’s fresh water • 1996–2007: net loss of ice doubled • Effect on sea level if melting continues

29. Sea Levels Are Rising – 90-99% certainity • Expansion of warm water and melting of land based ice– • Water will rise 18-59 cm (0.6-1.9 feet) during this century • storm surges of 6 meters (20 feet) • accompanying tropical cyclones and tsunamis

30. Sea Levels Rising • Degradation and loss of 1/3 of coastal estuaries, wetlands, and coral reefs • Disruption of coastal fisheries • Flooding of • Low-lying barrier islands and coastal areas • Agricultural lowlands and deltas • Contamination of freshwater aquifers • Submergence of low-lying islands in the Pacific and Indian Oceans and the Caribbean Maldives- Indian Ocean

31. Projected Decline in Arctic Tundra in Portions of Russia from 2004 - 2100 Melting of permafrost in tundra soils releases methane and carbon di oxide Loss of arctic tundra-reduce grazing lands for caribou Boreal vegetation would replace tundra

32. Ocean Currents Are Changing but the Threat Is Unknown • Melting glaciers, particularly in Greenland • Increased rain in the North Atlantic • Could add enough fresh water to disrupt the flow of deep and shallow ocean currents • Could climate of Northern Europe. N. America and Japan • Not thought to be an immediate problem on the ocean currents

33. Extreme Weather Will Increase in Some Areas • Heat waves and droughts in some areas- kill people, reduce crop production, expand deserts • Prolonged rains and flooding(flash floods) from heavy and prolonged precipitation • Will storms get worse? • More studies needed – Saunders and Lea (2008) • Hurricanes Katrina and Rita – lost 320 million big trees

34. Global Warming Is a Major Threat to Biodiversity • Most susceptible ecosystems • Coral reefs • Polar seas • Coastal wetland • High-elevation mountaintops • Alpine and arctic tundra Changes in water temperature, relative to coral bleaching threshold

35. Global Warming Is a Major Threat to Biodiversity • 30% of land –based plants and animals will disappear (temp change 1.5-2.5*C) • What about • Migratory animals • Forests • Some organisms will increase • Insects, Fungi, Microbes Exploding populations of mountain pine beetles Destroy lodge pole pine forests

36. 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 • Overall food productivity would decrease because of less productivity soil • Decrease in food production in farm regions dependent on rivers fed by snow melt • Genetically engineered crops more tolerant to drought

37. 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 O3 • More insects, microbes, toxic molds, and fungi Norman Myers – 150 to 200 million environmental refugees in this century

38. What Can We Do to Slow Climate Change…………….. • To slow the rate of global warming and climate change, we can • increase energy efficiency, • sharply reduce greenhouse gas emissions, • rely more on renewable energy resources • slow population growth.

39. What Can We Do to Slow Climate Change? • Governments can • subsidize energy efficiency and renewable energy use, • tax greenhouse gas emissions, • set up cap-and-trade emission reduction systems, • help to slow population growth.

40. Dealing with Climate Change Is Difficult • Global problem • Long-lasting effects • Long-term political problem • Harmful and beneficial impacts of climate change unevenly spread • Many proposed actions disrupt economies and lifestyles

41. What Are Our Options? • Two approaches • Drastically reduce the amount of greenhouse gas emissions • Recognize that some warming is unavoidable and devise strategies to reduce the harmful effects of global warming • Will we reach a political tipping point before we reach irreversible climate change tipping points?

42. We Can Reduce the Threat of Climate Change • Input or prevention strategies • Improve energy efficiency to reduce fossil fuel use • Shift from non-renewable carbon-based fossil fuels to a mix of carbon-free renewable energy resources • Stop cutting down tropical forests • Output strategy • Capture and store CO2 -

43. Avoiding Catastrophe: We Can Reduce the Threat of Climate Change • Socolow and Pacala • Climate stabilization wedges • Keep CO2 emissions to 2007 levels by 2057 • Brown: need to do more • Cut CO2 emissions by 80% by 2020 • 2008 book: Plan B 3.0: Mobilizing to Save Civilization

44. We Can Reduce the Threat of Climate Change • Output solutions • Massive global tree planting – 4 billion need to be planted • Wangari Maathai • Great Wall of Trees: China and Africa • Plant fast-growing perennials such as switch grass on degraded land which takes carbon dioxide from the air and stores it in the soil. Can be used to produce ethanol

45. SOLUTIONS Global Warming Cleanup Prevention Cut fossil fuel use (especially coal) Remove CO2 from smokestack and vehicle emissions Shift from coal to natural gas Store (sequester) CO2 by planting trees Improve energy efficiency Sequester CO2 deep underground (with no leaks allowed) Shift to renewable energy resources Transfer energy efficiency and renewable energy technologies to developing countries Sequester CO2 in soil by using no-till cultivation and taking cropland out of production Reduce deforestation Sequester CO2 in the deep ocean (with no leaks allowed) Use more sustainable agriculture and forestry Repair leaky natural gas pipelines and facilities Limit urban sprawl Use animal feeds that reduce CH4 emissions from cows (belching) Reduce poverty Slow population growth Fig. 19-13, p. 515

46. Fifteen Ways to Cut CO2 Emissions

47. Stepped Art Fig. 19-14, p. 515

48. Some Output Methods for Removing CO2 from the Atmosphere and storing it Tanker delivers CO2 from plant to rig Oil rig Coal power plant Tree plantation CO2 is pumped down from rig for disposal in deep ocean or under seafloor sediments Abandoned oil field Crop field Switchgrass CO2 is pumped underground Spent oil or natural gas reservoir Spent coal bed cavern Deep, saltwater-filled cavern = CO2 pumping = CO2 deposit Fig. 19-15, p. 516

49. Is Capturing and Storing CO2 the Answer? • Carbon capture and storage (CCS) – involves removing carbon dioxide from the smoke stacks of coal- burning power and industrial plants and storing them somewhere • Several problems with this approach • Power plants using CCS • More expensive to build • None exist • Unproven technology • Large inputs of energy to work • promotes continued use of coal • Effect of government subsidies and tax breaks • Stored CO2 would have to remain sealed forever: no leaking

50. Use Geo-Engineering Schemes to Help Slow Climate Change…….. • CCS – large scale geo engineering scheme opposed by scientists because long term effects on earth’s energy flow, chemical cycling processes and vital biodiversity are unknown • Injection of sulfate particles into the stratosphere by balloons, large jet planes, giant cannons • Huge amounts of sulfur dioxide injected into the atmosphere every 2 years • Would it have a cooling effect? • Would it accelerate O3 depletion?