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Climate
- 1. Climate ppt. by Robin D. Seamon 1
- 2. It’s all connected! Changes in one affects the other: 2
- 3. Weather- state of the atmosphere at a given time and place Climate- pattern of weather at a given location over time. 30 years + How do we classify climate systems? Koppen Classification System Based on vegetation & average monthly precipitation & temperature 3
- 4. A B C D E Tropical Dry Mild Continental Polar 4VIDEO Koeppen Climate Classification (5 min)
- 5. TROPICAL CLIMATES 5 • mT air masses (wet, warm) • Equator 1. Tropical wet (rain forest- Brazil) • Rainfall 59 inches/year; 68-91 degrees F 2. Tropical monsoon (Asia, W Africa) • Monsoon- wind system that reverses direction every six months: summer- sea to land (WET), winter- land to sea (DRY) 3. Tropical wet and dry (savanna) • 3 seasons: cool & dry, hot & dry, hot & wet
- 6. 6 Tropical monsoon climate: India Tropical rainforest, Brazil Tropical wet and dry climate- Tanzania
- 8. DRY CLIMATES 8 • Large daily & seasonal temperature variations • Hottest weather in arid climates (136 degrees F Libya) • Mountains often block warm, moist air • 30% of Earth’s land 1. Arid (deserts) • 4-12 inches of rain/year • Atacama desert- no rain in recorded history 2. Semiarid (Australian outback) • Enough rains for grasslands • Between arid & tropical climates
- 9. 9 Arid climate: Atacama desert, Chile Semi-arid climate: Australian Outback
- 10. MILD CLIMATES 10 • cT; mT Temperate regions; Distinct cold seasons • Continental air masses 1. Mediterranean (Greece) • Warm summers with short, mild, rainy winters • Cool, clear nights • W coasts of continents 30-40 degrees latitude 2. Humid subtropical (Georgia, US) • Hot, humid summers & Very cold winters • Precipitation spread over the year; hurricanes • E sides of continents 3. Marine (Seattle, WA) • Longer, cooler & wet winters
- 11. 11 Humid subtropical: Mediterranean climate: Slovenia Marine climate: Washington, US
- 12. 12 • cP; Hot summers, Colder winters, longer snows, shorter growing seasons, only in N. Hemisphere, away from bodies of water • Transitions between mild & polar climates • Extreme seasonal changes: autumn leaves, thunderstorms/tornadoes 1. Warm summer climate- (E Europe) • wet summers (humid) 2. Cool Summer climate- (Russia) • cold winters/snow from Arctic air masses 3. Subarctic- (Scandinavia, Siberia) • long, cold winters, little precipitation • Boreal, taiga CONTINENTAL CLIMATES
- 13. 13 Cool summer climate- Russia Warm summer climate- Romania Subarctic: Scandinavia
- 14. POLAR CLIMATES 14 • Within the Arctic & Antarctic Circles near North & South Poles 1. Tundra climate- (Northern Alaska) • short summers, temperatures can reach 50 degrees F; wildflowers & migratory birds, whales, nutrient rich waters 2. Ice Cap (Antarctica) • Temperatures rarely above freezing, constant ice • Skies clear, & precipitation low (Antarctica, largest, driest desert on Earth) • Little life
- 16. Periodic Disruptions: • La Nina- period where warm water moves towards the West Pacific (cooler, snows in US) • El Nino- a period when warm water is moving more towards the East Pacific (warmer & rainier in Central America) 16 La Nina El Nino VIDEO El Nino (3 min
- 18. ATMOSPHERIC VARIABLES What factors causes changes in the climate? 1. Biotic processes 2. Sun: Variations in solar radiation 3. Plate tectonics 4. Volcanic eruptions & LIPS 5. Cryosphere 6. Astronomy: Milankovich Cycles 7. Greenhouse gases • Oceans • Human-caused 18
- 19. 1. Biotic processes (life) • Respiration: breathing in/out O2 and CO2 • Transpiration: release of H20 and CO2 • Waste products • Recycling of gases after death 19
- 20. • Life affects gas cycles: • Carbon Cycle • Water Cycle • Cloud formation • Weathering EXAMPLE: 2.4 bya The Great Oxidation Event (put oxygen into atmosphere) http://guardianlv.com/2014/02/australian-crystal-found-is-4-4-billion-years-old/ 20 VIDEO That time oxygen almost killed everything (3 min)
- 21. 2. Variations in solar radiation • amount affects photosynthesis, precipitation, wind patterns, temperature (AFFECTS LIFE) • Sun has cycles of solar storms (flares) & sun spots which could affect earth & it’s life • sunspots/flares emit more solar radiation (warmer) EXAMPLE: 1550-1850 Little Ice Age- less solar activity Thames River: HENDRICK AVERCAMP'S LITTLE ICE AGE VIDEO: CC 4- Climate change, chaos & little Ice Age (10 min) 21
- 22. 3. Plate tectonics • shape of the continents determine ocean & wind currents • How heat is transferred • How much moisture http://www.bgs.ac.uk/discoveringGeology/climateChange/general/causes.html?src=topNav 22
- 23. EXAMPLES: • Mountains vs. plains • Large continent vs. several smaller ones • Connection of two continents block off ocean currents- Isthmus of Panama 23VIDEO Plate tectonics and Cont Drift: Mass Extinctions (7 min)
- 24. • IN PAST- tectonic movement caused big storage of Carbon- fossil fuels TODAY: Coal mines Carboniferous Era VIDEO:Formation of Fossil Fuels (2:30)) 24
- 25. 4. Volcanic eruptions & LIPs • spew gases into the atmosphere- changes chemistry (LIFE) http://www.bbc.co.uk/news/world-asia-29399306 Mt Ontake 9/27/2014 25
- 26. • LIP- large igneous provinces Places where large igneous rock beds indicate a past flow of lava from cracks in the crust 26VIDEO: Large Igneous Provice (45 sec)
- 27. • Can block out sunlight, preventing photosynthesis (LIFE) • Meteor induced http://news.nationalgeographic.com/news/2013/13/130212--chicxulub-asteroid-dinosaurs-volcano-mass-extinction- environment-science/ VIDEO: Large Igneous Province formation (2:00) 27
- 28. MODERN EXAMPLES: 1815 Mt. Tambora: Year without a Summer 1991: Mt. Pinatubo: global temp down 0.9˚F for 3 yrs 28
- 29. 5. Cryosphere: ice layer affects climate… http://www.toppforskningsinitiativet.org/en/programmer-1/program-2 http://rramu0153.wordpress.com/ 29
- 30. • During ice ages, sea levels are lower • water/run-off is trapped in ice • not in water cycle = DRIER VIDEO: Changing Sea Levels: Ice Age Sculpting Story (2 min) 30
- 31. • Albedo: amount of ice affects temperature: • more ice: more sunlight is reflected back off Earth • less ice: Earth absorbs more solar Energy • Carbon sink: ice keeps dead organisms from decomposing (more carbon) is absorbed than released; • as ice melts… more CO2 is released 31
- 32. 6. Milankovitch Cycle variation in intensity of sunlight due to slight variation in Earth’s orbit • Pace setter for cycles of warming & cooling 32
- 33. http://www.bgs.ac.uk/discoveringGeology/climateChange/ge neral/causes.html?src=topNav http://www.southwestclimatechan ge.org/figures/milankovitch Orbital shape: (eccentricity) Earth’s orbit changes from it’s elliptical shape; 100,000 yrs Orbital axis wobble: Changes in tilt causes strength of seasons 20,000- 40,000 yrs VIDEO: Orbital Forcing (1 min) 33
- 34. 7. Greenhouse Gases • More greenhouse gases = thicker blanket, holding in solar radiation (warmer) • Fewer greenhouse gases = thinner blanket, trapping less solar radiation= (cooler) http://www.ib.bioninja.com.au/standard-level/topic-5-ecology-and- evoluti/52-the-greenhouse-effect.html 34
- 35. • Natural Causes • Cold oceans absorb gases: CO2 • Warm oceans release gases: CO2 • CH (methane) from decay • Permafrost melting releases trapped CH4 4 35
- 36. • Human contributions & links to industrialization • Burning hydrocarbons: Release of carbon into the air through burning of fossil fuels & cement manufacture increases the greenhouse layer: CO2 carbon dioxide CH4 methane H2O water vapor 36 anthropocentric
- 37. Aerosol increase (tiny particles in atmosphere) Man-made CFC’s- chlorofluorocarbons can be put into aerosols & refrigerants; combines with and destroys ozone layer; banned in the US 37
- 38. Deforestation- cutting down of forests; • trees absorb CO2; by cutting them down, we are eliminating a natural carbon sink • We are cutting down 50 soccer fields of forest each minute • production of soy, timber, beef and palm oil. 38
- 39. 39
- 40. Slash & burn- burning of fields for agricultural purposes put hydrocarbons into the air 40
- 41. HOW DO WE KNOW CLIMATE HAS CHANGED OVER EARTH’S HISTORY? Ancient air is not around to be studied like rocks from the lithosphere are… or is it? • Paleoclimatology- study of ancient climate 41
- 42. SCIENTISTS USE CLUES IN… 1. Radiometric dating in rocks & sediment- Scientists compare sea floor cores (composition & past temperature) 2. Loess composition (ancient pollen in strata or rocks 42
- 43. 3. Ancient fossils: foraminifera in ancient sea beds 43
- 44. 4. Ice core data: layer size, pattern & composition Frozen water expands trapping air molecules! VIDEO : Drilling back to the Future (6:20) 44
- 45. Ice Core Samples • Samples of ancient air! • Show past atmosphere composition • Show aerosols (small particles in air) • Scientists can count layers yearly • Can be checked with major known eruptions (like Pompeii in 79CE) VIDEO 1: Drilling for Ice (3:20) 45
- 46. 5. Glaciers: Moraine sediments 6. Evidence left of past sea levels • On shore • in ancient coral beds 46
- 48. Earth’s pattern of Big Ice Ages have little ice ages (glacials) within them. In between glaciations, are periods of global warming (interglacials.) -------------------------------------------------------------------- LATEST GLACIATION: We’re in it (it’s why we have polar ice caps) Quaternary Glaciation 2.6 million years ago to the present • GLACIAL: Pleistocene Epoch: most recent Epoch in Earth’s history- glacier cycles ended 10,000 years ago 48
- 49. • Last ice age: around 10,000 years ago • Today we are in the Holocene Epoch, a period of warming (interglacial) 49
- 50. Glacials of the Quaternary glaciation: • Used to occur every 41,000 years • During the last 800,000 years, the spacing has stretched to every 100,000 years • Ice sheets grow for 90,000 years, take 10,000 years to melt during interglacials. Then the process repeats itself. 50
- 51. Ice cores and deep sea cores show the same pattern: Brief warmth http://www.skepticalscience.com/trend_and_variation.html 51 Longer cold
- 52. • Feedback mechanisms: natural responses that add to the system, causing it to continue in one direction ??? How is the Milankovitch Cycle a pace maker to trigger Ice Ages??? ??? What are the feedback mechanisms that amplify the Mil. Cycle??? 52
- 53. • 1980’s scientists noticed CO levels went up or down with the temperature in the past • Russian Vostok Station (1957 +) cores • CO2 & CH4 during Ice Age • CO2 & CH4 in warm periods GAS KEY 2 53
- 54. 54 • Climate Sensitivity CO2 levels in the past 750,000 yrs were at 180-280 parts per million • In 2012: levels were at 400 ppm and rising (methane too) VIDEO: Climate change Tetris (2:40)
- 56. Changes in Feedback? In PAST glaciations it appears that: • Sunlight • Temperature • CO2 & CH4 from oceans Making a warming loop until Mil. Cycle turns the cycle towards cooling again CO & CH increase 2 4Ice melts- albedo decreases Temperature increases 56
- 57. THEN orbital shift: • Sunlight • Temperature • CO2 & CH4 from oceans Making a cooling loop until Mil. Cycle turns the cycle towards warming CO & CH decrease 2 4Ice forms- albedo increases Temperature decreases decreased 57
- 58. Temperature CO & CH2 4 CO & CH2 4 Temperature FASTER SLOWER 58
- 59. IN THE PAST: • Temp increased b/c of sun angle shift • Sun angle shift started the loop, increasing the greenhouse gases & warmth NEW: • Orbital shift isn’t triggering the warming trend • extra greenhouse gases are starting the process • NOW- CO2 levels are increasing the temperature first 59
- 60. NEW: Gas levels rising faster than anything seen for millions of years & natural feedbacks are kicking in… • Warmer seas (What if all the Ice melted? 5:50) • Glaciers/ice caps are melting VIDEO NASA Sea Ice 2008 (3:00) • Sea levels rising video VIDEO: Sea levels rising (3:30 min) • Drying forests (VIDEO: Tropical Dry Forests (4 min) • Methane from Arctic melt (VIDEO: Exploding methane gas bubbles 3 min) • Ocean acidification (pH changes) VIDEO: NOAA Ocean Acidification 4 min • Species diversity is declining (VIDEO: Why biodiversity is so important 4 min) • Coral reefs dying (VIDEO: Coral Reefs &B Climate Change 12 min) 60
- 61. What will those changes be? VIDEO: Crash Course-Climate Change (10:00) 61 • Greenhouse warming & other human influences strong enough to change the natural trend • Could launch Earth into a wholly new climate trend (new pattern) CONCLUSION Geological record verifies with independent methods & data the process computer models are predicting: Disruption of climate from its recent patterns
- 63. http://en.wikipedia.org/wiki/Climate_change#mediaviewer/Fil e:NSFmonsoonsandclimatesince200AD.jpg Human civilizations affected by climate changes: VIDEO 2: 300 yrs of fossil fuels in 300 sec (5:30) VIDEO 1: Climate 101 with Bill Nye (4:30) 63 (VIDEO Scientists look back to Ice Age to Predict sea level rises 12 min)
- 64. Large scale development (urbanization) leads to regional changes in climate: Heat islands in large cities • NYC • Beijing • Chicago Smog Pavement & roofs get hotter than the air while shaded or moist surfaces in rural areas remain close to air temperatures 64
- 65. Heat Island Consequences: • Elevated emissions of air pollutants & greenhouse gases • Compromised health • Impaired water quality • Increased energy consumption (AC) 65 VIDEO: NASA Urban Heat Islands 2:30
- 66. Strategies to combat heat islands: (EPA) • Planting trees & vegetation in cities • Green roofs: growing vegetation on rooftops Beruit NYC Chicago 66 VIDEO Do Cities need more green roofs NPR: 3:50
- 67. Strategies to combat heat islands: (EPA) • Cool roofs: installing roofs that reflect sunlight away from buildings • Cool pavements: using paving materials that reflect & not absorb light 67VIDEO: Cool Roofs (2 min)
- 68. • Smart growth: mix land uses, compact building design, walkable neighborhoods, preserve open space, farmland, direct development towards existing communities, variety of transportation choices, make development decisions predictable, fair, & cost effective 68 VIDEO: Climate Change: What can we do? 2:10 VIDEO: What you can do about climate change(10 min)