1. Climate

2. Climate-The average weather conditions for an area over a long period of time. Climate is described by using…

3. Climate Influences 1. Latitude 2. Elevation/Topography Top of a mountain vs. flat land 3. Heat Absorption and Release Proximity (distance) to large bodies of water

4. Latitude Latitude-determines amount of solar energy certain locations receive based on… Sun angle Equator = most direct sun light (high sun angle) Poles= most indirect light (low sun angle) Latitude affects air pressure which create Global Winds.

5. Temp Range and Latitude LatitudeAve. Temp.Temp. Range Low (equator)Warm!Low Mid (Michigan)ModerateHigh High (poles)Cold!Low

6. Global Winds Because Earth receives different amounts of solar energy at different latitudes, differences in air pressure are created across the globe which in turn creates global winds. These global winds affect many weather conditions such as precipitation and temperature. remember-winds (and currents) do not move in a straight line because Earth is spinning-coriolis effect. Northern Hemisphere deflects to the RIGHT Southern Hemisphere deflects to the LEFT Reverses direction at latitudes 30, 60 and 90 Begins at equator

8. Heat Absorption and Release Heat absorption and release-The way solar energy strikes earth and is absorbed or released influences temp. Land vs. Water: Land warms/cools faster (unmoving) Water warms/cools slower (waves, currents keep mixing, specific heat) Evaporation occurs more rapidly over water than over land Is a cooling process

9. Heat Absorption and Release Currents influence the air it contacts. Winds blow towards shore… away from shore... N.Europe: big influence, U.S. not much.

10. Heat Absorption and Release Temperature difference between land and water sometimes cause winds to shift seasonally. Summer: land heats faster and pulls ocean air in (winds blow toward land). Winter: land cools faster-ocean is warmer causing winds to blow toward sea These seasonal winds are called “Monsoons” Air moves from H to L pressure and brings torrential rains, etc…

11. Topography Features of land, such as mountains can control the flow of air through a region. Elevation above sea level creates distinct temperature differences-every 100m above sea level experiences a temperature drop of 0.7 degrees Celsius. The rising, cooling and condensing of air over a mountain affects the climate on both sides.

12. Our Atmosphere Mostly Nitrogen (78% on average) 21% Oxygen Layered 4 layers, we live in troposphere Heated by Earth Sun heats Earth, Earth heats atmosphere Contains Greenhouse Gases Good in moderation (needed for life as we know it)

13. Greenhouse Gases Trap heat in atmosphere CO 2 (Carbon dioxide) Most recent hype- human production from combustion (burning) fossil fuels Easy to monitor Greatly increasing Ocean is largest reservoir CH 4 (methane) Product of digestion VERY efficient (traps lots of heat) H 2 O (water vapor)

14. Ancient Climates Climatologists study evidence left by past climates to determine patterns and predict future changes. Ice Cores Air trapped in ice shows atmosphere conditions when freezing took place Oxygen isotopes, CO 2 content, etc. Tree Rings Pollen Counts

15. Ancient Climates Con’t Varve Count Shows melting/freezing patterns of glaciers Similar to tree rings, only for glaciers Sea-floor Sediments What types of animals were living, what were their shells made of, what types of gases would be present Fossils Types and sizes of plants/animals

16. Potential Causes of Climate Change Tectonic Plates Movement of by shifting tectonic plates changes wind flow and ocean currents which changes temperature and precipitation (climate) The climate of Michigan is not the same as it was millions of years ago. Geographically, what is now Michigan was near the equator. A warm shallow sea once covered what is now Michigan Shifting plate tectonics explains the movements of continents to new locations and the uplifting of Michigan into a new, cooler climate. Evidence of this is found in the state stone, the Petoskey stone, which is fossilized coral.

17. Orbital Changes Milankovitch Theory Orbital changes-circular or elliptical-changes Earth’s distance from the sun-causes cooling or warming of atmosphere Change in tilt affect temperature range between seasons Precession-the wobble of Earth on its axis can reverse seasons http://www.youtube.com/watch?v=TWJyeyV92W4 Volcanic Eruptions (Massive) Meteorite Impacts (Gigantic) Sunspot Activity (Mins and Max) Wild Fires (Massive) Human Impact (7 Billion of us) Potential Causes of Climate Change

18. Why Does it Matter? Temperature Increase Global average Increased approximately 1 degree Celsius over last 100 years increased evaporation-drier conditions Melting of polar ice, rising sea levels Rising Sea Levels Flooding of coastal areas where about 50% of Earth’s population lives 15 cm (6 in.) so far

19. Why does it Matter? Arctic Ice Melting ½ thickness of 1950 Potential impact to ocean circulation Speeds up warming (less reflected energy) Sea-surface Temperatures Rising ¼ coral reefs dead in last 20-ish years More acidic seawater Impact on shelled aquatic organisms

20. Why Does it Matter? Permafrost Melting layer of soil or rock frozen all year round When permafrost melts, the land above it sinks or changes shape, damaging buildings, roads, airports, and ecosystems. When permafrost melts the carbon trapped inside is released to the atmosphere leading to more global warming

21. Why Does it Matter? Areas of heavier rainfall Flooding Warmer temps= more evap. = more precip. Areas of more extreme drought Higher evap. = more drought in regions Changing Ecosystems Growing seasons changed Migration patterns changing Invasive species migrating

22. Controversy…not anymore. Controversy really isn’t about Defining global warming Measuring global warming The trick is How long does climate show change before it is serious? How fast is climate supposed to change? What impact have humans had on climate change?

23. So we know about global warming- what about global cooling? A long period of climatic cooling is known as an ice age During an ice age the continents are glaciated (cover with ice) repeatedly. Begin by a long, slow decrease in Earth’s average temperature. Only takes a 5 degree Celsius drop to start an ice age.

24. Glacial and Interglacial Periods Continental glaciers advance and retreat many times during an ice age. Advance during a period of cooler climate- glacial period Retreat during a period of warmer climate- interglacial period.

25. Glaciers Glaciers: Massive ice packs that move across land Formation: More snow falls than melts over years and years Found: Mountains (alpine) or cold areas (continental) Largest: Antarctica Not a glacier: Arctic (all ice is floating in sea at North pole, no land under it)

26. Great Lakes Formed! 10,000 years (or so) ago Originally river beds (low areas) Wisconsin Glaciation Period Glaciers follow river beds (easy path) Glaciers move into Ohio, Kentucky, northern Tennessee While retreating, melt water is trapped, new drainage pattern formed HOMES!