Global Warming & Ozone Depletion

1. Global Warming & Ozone Depletion AP Environmental Science

2. Electromagnetic Spectrum

4. Introduction to the Atmosphere

7. Climate Change/Global Warming Note: in discussion of climate change, one needs to keep in mind that we are discussing long term trends, 30 years or more.

8. Patterns in Climate Change

9. Patterns in Climate Change • Rotation of glacial and interglacial periods • Glacial – ice ages • Interglacial – time between ice ages • Past 10,000 years – fairly stable climate and average surface temperature of an interglacial period. • Temp has risen drastically in the last 100 years due to human impact

10. How do we know about past temperatures? • Radioisotopes in rocks, fossils, plankton, & ocean sediment • Ice cores • Pollen from lakes & bogs • Tree rings • Recorded temperatures since 1861

11. Human Activities & Global Warming • Burning Fossil Fuels • Deforestation • Agriculture • All the above create more greenhouse gases, which in turn trap more heat in our atmosphere.

12. IPCC (1988)Intergovernmental Panel on Climate Change • Last 2007 Report Findings • Earth’s atmosphere has been warming since 1960 due to increased concentration of greenhouse gases. • The increase in greenhouse gases in caused by human activity. • If this continues at the current rate, major rapid warming and climate change will occur this century. • This will cause ecological, economic, and social disruption by degrading food/water supplies and ecosystems, flooding of low lying coastal communities/cities, and elimination of many of the Earth’s species.

13. IPCC (1988)Intergovernmental Panel on Climate Change • Evidence collected for the IPCC 2007 report & after the report was published. • Between 1906-2005, temperature has risen by 0.74 ˚C (mostly since 1980) • Greenhouse gas emission rose by 70% between 1970-2009 • The 2000s was the warmest decade since 1881 • Glaciers are melting, floating sea ice is shrinking at increased rates • Sea level rose by 19cm during the 20th century. For comparison, it rose by 2cm in the 18th century and 6 in the 19th century

15. Contributors (or not) to Climate Change

16. CO2 Emissions • 1850 = 250 ppm • 2010 = 389 ppm • 2050 = 560 ppm @ current rate • 2100 = 1390 ppm @ current rate • Tipping point = 450 ppm • Irreversible damage • Need to stabilize around 350 ppm

17. CO2 Emissions • 2009 Largest CO2 Emitters (in order) • China • US • European Union (27 Countries) • Indonesia • Russia • Japan • India *China & US responsible for more than ½ of current emissions. • Per Capita: • Australia • US (5x per capita/China) (200x per capital/poorest countries) • Canada • Netherlands • Saudi Arabia *China: more ppl, less per capita, however by 2050 could be responsible for 60% of CO2 emissions

19. Waste Heat (Latent Heat) • 2nd law of thermodynamics: energy transfer results in a loss of energy as heat (aka waste heat) that can not be recycled • Burning of fossil fuels not only produces greenhouse gases but also waster heat. • Inefficient energy systems currently in use: incandescent light bulbs, internal combustion engine, nuclear fuel cycle, coal power plants, etc. produce large amounts of waste heat. • Even solar panels waste 80-90% of the energy trapped, wind turbines was 50-60%

20. The Sun • Scientists have determined that the sun’s output has actually decreased and that warming is occurring from the Earth’s surface up into the atmosphere. • Warming is not caused by the sun, but by human activity.

21. Oceans • Absorb ~25/30% of CO2 emissions along with heat • However, as water temperature increases, less CO2 can be absorbed • Increased CO2 at the surface of the ocean has increased the acidity of the ocean by 3% in the last 200 years • Carbon dioxide reacts with water to make carbonic acid (H2CO3) • Threatens any organism with calcium carbonate (CaCO3) such as corals & shelled organisms • Acidity decrease the population of phytoplankton • A producer in the marine food web • Less CO2 removed

22. Clouds • Cool and warm the atmosphere • Warmer temps  more evaporation  more cloud cover • Cumulus clouds @ low altitudes  decrease surface warming by reflecting sunlight back into space • Cirrus clouds @ high altitudes  prevent heat from escaping into space  increase warming • It is UNKNOWN which plays a bigger role at this point. • Cumulus or Cirrus?

23. Outdoor Pollution • Aerosol air pollution: slow warming because they reflect sunlight and cool the atmosphere, as well as, serve as condensation nuclei for cloud formation • However, they do not have a big effect since they are washed out within weeks to months so their use is reduced. • So do we…increase pollution to slow warming? • Unethical since approximately 800,000 people die/year from air pollution complications.

25. Effects of Global Warming

26. Severe Drought • Occurs when evaporation from increase temperatures exceed the amount of precipitation in an area for prolonged parts of time. • Growth of vegetation decreases • Forest/grassland dry out  wildfires  increased CO2 • Declining stream flows  decrease in available surface water  increase in evaporation • Increase in irrigation from farmers for drier conditions  shrinking of fresh water supplies • Can eventually lead to water shortages for 1-3 billion people, declining biodiversity, and expansion of dry biomes

27. Melting Snow & Ice • Snow & Ice cool the Earth by reflecting light • Increase temperatures  melting  warming of poles  more melting  more warming  more melting  more warming… • Soot darkens snow and ice  absorbs heat  melting  … • Summer sea ice in the Artic is disappearing • Mountain glaciers are melting (important for storage/release of water)  food shortages • Could also lead to volcanic activity in Iceland • Permafrost locks up CH4 (methane)  melting  more CH4 released  more warming  …

29. Rising Sea Levels • Sea water expands as it warms  rising sea levels  melting of land based ice • Can lead to • Destruction of 1/3 of world’s estuaries, wetlands, coral reefs • Destruction of fisheries • Erosion of barrier islands • Flooding of agricultural lowlands and deltas (where most rice is farmed) • Salt water contamination of fresh water sources = less water supply • Submersion of islands (Indian, Pacific, Caribbean – displacing 1/20 people) • Flooding of coastal cities (Calcutta, Mumbai, Dhaka, Guangzhou, Ho Chi Minh, Shanghai, Bangkok, Rangoon, New York, Miami, Boston – displacing 100 million people)

30. Extreme Weather • Severe droughts and heat waves • Prolonged rain & snowfall • Hurricanes/typhoons (scientists debate this)

31. Decrease in Biodiversity • Polar regions • Polar Bear in the Artic & Penguins in the Antarctic • Organisms with limited range or climatic tolerance • Coral reefs (coral bleaching) • Polar seas, coastal wetlands, mountain tops (high elevation), tundra, forests • Increase populations of insects & fungus that damage trees, crops, and carry disease

33. Agriculture • Cause of 1/3 of global warming due to deforestation and food production (burning of fossil fuels) • Global warming will cause a decrease of agriculture in some areas, but will make it possible to grow crops in other areas that were not previously able to. However, the soils in these new areas may not be rich enough in nutrients, so it is predicted that agriculture will decrease overall  food shortage • By 2050, 200-600 million poor will be malnutritioned or starve

35. Human Health • Most affected: older, poor health, urban poor • Heat related deaths will surpass deaths caused by cold weather • Hunger/malnutrition • Insects, microbes, molds, fungus that cause disease will thrive • Pollens will increase  allergies and asthma • High levels of water vapor in the atmosphere will cause air pollution

38. Fixing, Preventing, & Cleaning Up Global Warming

39. A Complex Problem • Global Problem • Long term Political Issue • Harmful & Beneficial effects that are NOT evenly distributed amongst the world • Solutions are controversial because they will disrupt economies and lifestyles • Humans are not hard wired to respond to long term threats (per social scientists)

40. The Choices • Slow it • Reduce Harmful Effects • Suffer & Ignore It

41. Prevention • Cut fossil fuel use (especially coal) • Use natural gas instead of coal • Improve energy efficiency • Develop and use renewable energy resources • Share knowledge with developing countries • Reduce deforestation • More sustainable agriculture and forestry • Put a price of greenhouse gas emissions • Reduce poverty • Slow human population growth

42. Clean Up • Remove CO2 from smoke stacks and vehicle emissions • Plant trees (remove CO2 from the atmosphere) • No till cultivation • Bury CO2 emissions underground/deep in the ocean with no leakage • Repair leaky natural gas lines/facilities • Used feed that reduces the amount of methane (CH4) emitted from livestock

44. Governments • Strictly regulate CO2 & CH4 as air pollutants • Tax CO2/CH4 units • Cap total human generated CO2/CH4 emissions, issue permits, allow companies to trade amongst themselves (Cap & Trade) • Increase subsidies to energy efficient companies • Transfer technology to less developed countries

45. Kyoto Protocol • 12/1997 delegates from 161 nations met in Kyoto, Japan to negotiate a treaty to slow global warming and its projected climate disruption • Went into effect 2/2005, expires 2012 • By 2011 191 of 194 countries have ratified the agreement • United States has not • Requires 36 countries to cut emissions of CO2, CH4, N2O to at least 5.2% • Has been slow and some say ineffective • CO2 levels have actually increase 35% faster than originally predicted in Kyoto

46. Participation in the Kyoto Protocol, as of December 2011 Brown = Countries that have signed and ratified the treaty Blue = No intention to ratify at this stage. Dark blue = Canada, which withdrew from the Protocol in December 2011 Grey = no position taken or position unknown

47. Adaptations • Develop crops that needs less water • Waste less water • Move people away from low-lying coastal areas • Prohibit new construction on low-lying coast areas or build houses on silts • Stockpile 1-5 year supply of key foods • Expand existing wildlife preserves towards the poles • Move hazardous material storage tanks away from the coast

48. Ozone Depletion

49. The Ozone Layer • Keeps ~95% of the sun’s UV rays from reaching the Earth’s surface

50. Ozone Depletion • Chlorofluorocarbons (CFCs) disrupt the ozone making process leading to the depletion of ozone  allowing for the passing of harmful UV rays