Global Climate Change

1. Global Climate Change Past, Present and Future

2. Review: Part I- Weather and Climate • Weather vs. Climate • Atmosphere / Geosphere / Hydrosphere / Biosphere • Solar Radiation • Uneven Heating of Earth’s Surface and Specific Heat • Rotation of Earth on its Axis • Angle of Insolation • Proximity to Large Bodies of Water • Coriolis Effect • Thermohaline Conveyor • Southern Oscillation (ENSO/LNSO) • Greenhouse Effect / Greenhouse Gases • Albedo Effect • Volcanic Activity • Waste products of Animals / Decomposition • Vegetation – Carbon Sinks and Evaporation Rate

3. Let’s take a look at a history of how we have looked at climate change

4. Global Climate Change “The Past”

5. ICE HOUSEor HOT HOUSE??? During the last 2 billion years, the Earth's climate has alternated between a frigid "Ice House", like today's world, and a steaming "Hot House", like the world of the dinosaurs. This chart shows how global climate has changed through time.

6. Did you ever hear the story of Goldilocks and the Three Bears? Papa’s Porridge was too hot Mama’s was too cold but baby bear’s was juuust right…

7. Our Climate Works A Lot Like Goldilocks Very Specific Preferences…. Goldilocks Principle • Too many greenhouse gases, the Earth gets too hot. • The Earth gets too hot, we die • Too few greenhouse gases, the Earth gets too cold • The Earth’s too cold, we die • In other words, the earth’s climate has to be “juuuuustriiight” in order for life (as we know it) to continue to exist

8. Snowball Earth Theory • controversial hypothesis that the Earth underwent a worldwide glaciations, when even tropical regions became ice covered • Temps dropped to -50 °C • All the oceans froze, and glacial conditions persisted for 10 million years or more perhaps as many as four times • Occurred between approx 750 and 580 million years ago • Large concentration of equatorial land masses • Albedo Effect - Ice reflects heat, oceans absorb heat • Lack of rain disrupted carbon cycle, greenhouse gases dropped dramatically VIDEO

9. SNOWBALL EARTH • Reversed by volcanic activity CO2 Increase • Sea ice shrinks, increasing temperature • Earth began warming and life “exploded” in diversity • 250 MYA – suddenly earth’s temp dramatically increases and 95% of all species on earth are wiped out. Greatest mass extinction ever. • Dino flatulence VIDEO

10. Earth’s Primitive Atmosphere • Earth’s Primitive Volcanoes expelled vast amounts of CO2 into the atmosphere • The atmosphere began to heat up tremendously as the gases trapped the sun’s radiation • Simple living organisms (bacteria, algae) evolved and incorporated CO2 into their life molecules (basis for organic chemistry- carbs, nucleic acids, amino acids, lipids all require carbon and oxygen) • Organisms die and are buried deep beneath the earth, “sinking” CO2 beneath the ground for millions of years • Cooler climate evolves without all of the CO2 • Complex life evolves • Complex life digs up dead organisms, burns them and releases CO2 back into the atmosphere, thus creating freaky hot conditions and global temperatures like that of Primitive Earth. VOILA!!

11. Turning Back Time- Mimicking Earth’s Early Inhospitable Environments • Earth’s levels of CO2 have not been this high since roughly 250,000,000 years ago! • Levels are rapidly increasing as we spew the CO2 that has been stored underground (in dead organisms) back into the atmosphere • At the present rates, temperatures could climb to what they were during the most severe mass extinctions

12. Global Climate Change “The Present”

13. Rising Global Average Temperatures • Global average surface temperature increased over the last 100 years by about 1.1 degrees Fahrenheit. (0.6 Celsius) • There is at least a 90 percent chance that the 1990s was the warmest decade for the planet, since 1861 and the beginning of instrumental records • There is strong evidence that most of the warming observed over the last 50 years is attributable to human activities. • 2006 had an annual average temperature of 55°F in the United States, which is 2.2°F (1.2°C) above the 20th Century mean. • Each of the last ten years (1998-2008) has earned a spot in the rankings of the 25 warmest years on record. • 2007 tied with 1998 as the second warmest year in a century, behind 2006, the warmest year in the century.

15. Rising Concentrations Of Greenhouse Gases • Up until the last two hundred years, atmospheric CO2 concentrations had stayed between 265parts per million (ppm) and 280 ppm • according to analyses of gases obtained from ice cores that reflect the past 10,000 years. • Atmospheric CO2 concentration at the beginning of the 21st Century is approximately 365 ppm. • Atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased since 1750: • CO2 - 31 % • CH4 – 151 % • N2O – 17% • Humans added more than 270 billion metric tons of carbon to the atmosphere since the 1800’s. • About three-quartersof human emissions of CO2 to the global atmosphere during the past 20 years is due to fossil fuel burning.

16. Current Evidence Of Climate Change

17. Sea level is rising. • During the 20th century, it is estimated that sea level rose about 15 cm (6 inches) • due to melting glaciers and expansion of warmer seawater. • It could rise much more than that in the next 100 years.

18. Every 1 degree C increase = 100 ft. of beach gone.

19. Arctic sea ice is melting. • The summer thickness of sea ice is about half of what it was in 1950. This is causing the Arctic to warm up faster. (positive feedback). • Fresh cold water floods into the thermohaline conveyor, traps warmest water in tropics, leading to drought in other regions Glaciers and permafrost are melting • Over the past 100 years, mountain glaciers in all areas of the world have shrunk and so has the amount of permafrost in the Arctic. Greenland's ice sheet is melting faster too. • These reserves of fresh water Damages our water supply in times of drought!! • Changing Glaciers VIDEO

20. The ocean is warming. • Warmer waters in the shallow oceans make coral reefs less healthy. • Loss of 60 percent of tropical corals is threatening barrier reefs. • Coral Bleaching: About a quarter of the world's coral reefs have been “bleached” in the last few decades. • Reefs lose their healthy green color and die because the symbiotic algae cant survive the heat. VIDEO

21. More rain causes flooding. Warmer temperatures have caused more intense rainfall in some places. This can cause rivers, storm drains, streams and reservoirs to overflow in rainiest seasons Washes away soil and carries ground contaminants into major watersupplies Flooding is a problem, especially in the higher latitudes.

22. Extreme drought is increasing • While some areas experience more rain and flooding, Higher temperatures cause a higher rate of evaporationand more droughts in other areas of the world • Most effected: inland regions at lower-middle latitudes • Inability to provide fresh drinking water or water for irrigation • Strict rationing • Reservoir, Georgia (2008)

23. Ecosystems are changing.

24. Ecosystems are changing. • As temperatures warm, animals and plants may either look for a cooler place to live or die. • Vulnerable species include many endangered species, coral and animals of the reefs, and polar animals. • Warming has also caused changes in the timing of spring rain events and the alter the length of the growing season of naturally occurring plants. • Plants that have grown in one region for a long time are no longer suitable and are replaced by other species of plants and animals that feed on them. • If animals cannot migrate, they are left to starve • For humans, this drives the price of food crops up as supply drops.

25. Hurricanes have changed in frequency and strength. • Recipe for a hurricane:

26. Hurricanes have changed in frequency and strength. Picture of Hurricane Elana over the Gulf of Mexico taken from orbit. (Image courtesy of NASA)

27. Hurricanes have changed in frequency and strength. • There is evidence that the number of intense hurricanes has increased in the Atlantic since 1970. • Category 5 storms were only theoretical until the past 30 years • Will there be a category 6? • Scientists continue to study whether climate is the cause. Picture of Hurricane Elana over the Gulf of Mexico taken from orbit. (Image courtesy of NASA)

28. Heat waves more frequent. • Heat waves have become increasingly more frequent and are lasting longer • It is likely that heat waves will become more common in more areas of the world. • In 2003, 35,000 people died in Europe due to a series of severe heatwaves. • In 2005, 14000 people died in France in a single heatwave • Outdated architecture was designed for climate from LIA Period • Elderly, young, sick and poor are most endangered .

30. Seawater is becoming more acidic. • When carbon dioxide, a greenhouse gas, gets into the oceans, it makes the water more acidic. • Carbonic Acid • Acidity disturbs balance of entire marine ecosystems. • impact coral reefs, such as all reef species • collapsing our fishing industries • decimating marine food web from the bottom-up • (so long, Nemo and Dory), dolphins, manatees, sharks, tuna, salmon, whales…

31. How Do We Know that Temperatures are Rising? • 1.Temperature/Climate datameasurements Compare data recorded in recent centuries • Farmers almanacs, Royal scribes • World metrological data from the past century • Very limited timeline • 2.Arctic Ice Cores Compare the ratio of CO2 to O2 and greenhouse gases back tens of thousands of years • 3. Ocean Sediment Cores: Compare the ratio of the tiny warm-water vs. cold-water marine microorganisms buried beneath the ocean sediment (forams, coccoliths) • 4. Tree Ring Analysis: Compare the size of rings to determine particularly dry or cold seasons. Older trees carry more information

32. Monitoring Sea level Change • Oceans can store up to 80% of solar radiation in the form of heat (heat “sink”) • Ice sheets are melting rapidly • Changing density of ocean by adding more fresh water • Measuring sea levels yields disturbing data • VIDEO

33. Monitoring Climate Change • Tools to montior Climate ChangeVideo

34. Ice cores • http://videos.howstuffworks.com/tlc/29806-understanding-antarctica-video.htm

35. Global Climate Change “The Future”

36. What will these 6 degrees mean for us?

37. One Degree Celsius Arctic is ice free most of year Coastal flooding More hurricanes Food shortages from drought Two Degrees Celsius Polar bear habitat loss/starvation Insect Migration Crop Migration Loss of Marine Life – Coral Reefs Extinct (canary in the coal mine) Three Degrees Celsius No arctic ice Disappearing snow caps More el nino patterns Amazon withers Heat wave fatalities Four Degrees Celsius Oceans rise Glaciers gone Disappearing water supply Major cities/countries washed away Five Degrees Celsius Aquifers dry up / snow pack disappears Cities collapse Climate refugees Poorest suffer most Six Degrees Celsius Mass extinctions Algae dies off Severe desertification “Doomsday Scenario” Six Degrees Could Change the World

38. But…..

39. … it is projected that if we continue on the same trend of CO2 production and consumption, global temperatures could increase by 5 t010degreesCelsiusby the year 2100.

40. What could add to this huge 5 degree jump?

41. 1. Warming can be further accelerated by the release of Methane Hydrates • Methane molecule trapped or “frozen” in a net of water molecules • One molecule of methane is 8x as potent as a molecule of CO2, but considering how much methane there is, it is actually 23x more potent than CO2) • Stored in huge pockets beneath ocean or beneath permafrost regions (Alaska, Siberia) • Formed when buried organic matter decayed • The flammable GHG methane is released into the atmosphere by: • Mining for fuel (intentional and accidental) • Increase in Water Temperature releasing “frozen” methane hydrates buried beneath shallow seas • Carbonic acid eroding stability of sediments that cover the methane hydrates

42. There’s a lot of hydrocarbon molecules frozen in methane hydrates • if all of that if all of it were to thaw out and enter the atmosphere we could be facing a greenhouse effect that could be hundreds of times worse than what scientists currently predict • if we destabilize large amounts of frozen methane and that enters the atmosphere, we’re literally cooked. • The question is can we safely and economically extract methane from these deposits, and that’s a question that nobody has a good answer for right now. • Release may lead to an intense positive feedback loop

43. VIDEO More Methane Hydrates Escape into Atmosphere Higher temperatures from Global Warming

44. Global Methane hydrate Deposits

46. 1. 4. 2. 3.

47. 2. A BIG CLIMATE MYSTERY: • The temperatures on Earth are increasing, so what should be happening to the rates of evaporation? • Evaporation should beincreasing as well • the levels of evaporation of water (pan evaporation) areactually decreasing • Doesn’t seem to make sense… so why is it happening? VIDEO – GLOBAL DIMMING

48. Is there something hiding the “real” effects of global warming??? • As more ice melts, the earth becomes darker, absorbing more heat • As it absorbs more heat, more evaporation occurs, leading to more water vapor in the air (can’t become clouds, but acts as insulating greenhouse gas) • Additional particulate pollution helps form more clouds • Aerosols • Jet contrails • Clouds block incoming solar radiation • How? • High albedo- reflect sunlight back into space • Makes effects of global warming appear less • Called “Global Dimming”

49. Shutting down the thermohaline conveyor • VIDEO

50. Can you see how this may present a PROBLEM? • If we don’t clean up air, it means: • more asthma and respiratory illnesses • Cleaning up air means: • reducing the cloud cover and increasing the rate of heating of earth’s surface and all that comes along with it. • So what do we do??? • (Sadly, nobody has an answer for that… ) • Somehow, we must address BOTH problems