Transcript Biosphere
Earth’s Climate What is Climate? Climate Basics… What is climatology? the study of Earth’s climate and the factors that affect it What is climate? long-term weather patterns of an area What are four main factors that climate describes about an area? Temperature Precipitation Wind Seasonality Factors That Affect Climate… Latitude http://www.brockmann-consult.de/iavisa-info-web/data-set-generation.html Factors That Affect Climate… Topographical Effects http://www.sonoma.edu/users/f/freidel/global/figure%2002-20.jpg Factors That Affect Climate… Air Masses A tropical island in the Atlantic Ocean has a maritime tropical climate (warm and humid) because it’s climate is controlled by the mT air mass. http://www.atmos.illinois.edu/earths_atmosphere/images/airmasses_fronts/air_masses.gif http://travel.nationalgeographic.com/travel/countries/bahamas-guide/ Ocean Currents Determine Climate… Write notes on Lesson! Currents affect climate… a. East coasts have warm currents. (The Gulf Stream… causes our climate to be humid subtropical.) b. West coasts have cold currents. (The California current from the Bering Sea… causes it to have a Mediterranean climate that is cool and dry.) See next slide… Proximity to Oceans Determine Climate Coastal climates are more temperate than continental (interior) climates… a. Differential heating of water and land means that … oceans take longer than continents to cool down or warm up (Remember how long hurricane season lasts? Until Nov 30th!) b. Oceans take longer to cool down after summer. Oceans act as heaters in the winter. c. Oceans take longer to warm up after winter. Oceans act as air conditioning in summer. d. Our coastal communities – such as the Outer Banks or Wilmington - are cooler in the summer and warmer in the winter. High Altitudes Determine Climate… http://www.appstate.edu/about/ a. Boone is over 3000 ft above sea level so it is almost always 10° F cooler than Winston-Salem. A mountain top is cooler b/c… it is farther from the conduction of heat from Earth’s surface. Climate Classification Climate Classification… The Koeppen Classification Scale http://theweatherchannelkids.com/climate-code/be-eco-friendly-for-the-animals/tropical-climate/ Climate Classification… TROPICAL – found along the equator (23.5º S to 23.5º N) – Constant high temperatures – A lot of rain (up to 600 cm of rain) – high biodiversity http://accessscience.com/search.aspx?rootID=798501 Climate Classification… DRY (arid or semiarid) – western USA, central Asia & Australia, N. Africa – cT air (warm & dry) – Low rainfall (precipitation) – Scarce vegetation http://accessscience.com/search.aspx?rootID=798501 Climate Classification… MILD – NC is in humid subtropical a. The North Atlantic Current (Gulf Stream) is responsible for N.C.’s climate b. The other two… • Marine West Coast (WA, OR) • Mediterranean (CA) http://www.solcomhouse.com/gulfstream.htm Climate Classification… CONTINENTAL… found in the Northern Hemisphere a. Weather… • Rapid, violent changes • Extreme seasonal temps • Clashing air masses (tornado alley) b. These locations have more seasonal extremes b/c …they are far away from moderating effect of the ocean which warms and cools slower than land. http://accessscience.com/search.aspx?rootID=798501 Climate Classification… POLAR (& Subarctic and Tundra) are found near or at the poles. – Subarctic is a subclass of continental climates – Tundra is a subclass of polar climates http://accessscience.com/search.aspx?rootID=798501 http://www.squidoo.com/machupicchuruins?utm_source=google&utm_medium=imgres&utm_campaign=framebuster Microclimates… 1. What is a microclimate? localized climate that differs from main regional climate a. These microclimates are colder than the surrounding climate. b. The microclimate of a very high mountain is classified as “high elevation” which is pink/purple on map. A Llama in at Machu Picchu in the Andes Mountains Heat Islands… What is a heat island? localized place climate is warmer than the area around it – lots of buildings & little vegetation. Where would you expect to find heat islands in the Piedmont? Greensboro, Winston- Salem, Raleigh http://www.weatherquestions.com/What_is_the_urban_heat_island.htm Biomes Biomes… Biomes… large geographic regions with similar climate and plants & animals with similar adaptations. http://www.windows2universe.org/earth/polar/images/polar_bear_sm.jpg http://sasd.k12.pa.us/uploadedImages/ShalerAreaMS/Staff/GuidishD/tundra.jpg • Climate… Tundra (Polar Zone) precipitation low (cold air) Average temps constantly low seasons - very long winters! • Plants… grasses (shallow roots stay alive under snow) • Animals… Polar bears (big and fat!) • Air Masses – cP and cA • Soil – permanently frozen (permafrost) The Tundra • Climate… Avg precipitation – Biomes…Taiga little – mostly snow! Avg temperatures - low most of the year seasons - long winters • Plants… evergreen trees (needle like leaves conserve water) • Animals… • grizzly bears, elk, moose (hibernate/migrate) • Air Masses – cP and A • Soil – supports trees Taiga, Grand Teton NP, WY • Climate… Average precipitation – Deciduous Forests moderate Average temperatures - warm, humid summers/ dry, cool winters 4 equal seasons • Plants… US! seasonal forests – drop leaves to conserve water • Animals… black bears, foxes, deer – give birth in the spring • Air Masses – mT & cP • Soil – rich and thick http://www.solcomhouse.com/gulfstream.htm • Climate … Average precipitation extremely low (dry) Average temps usually high/ can be cold at night Semi-arid have rainy seasons • Plants… cactus - stores water • Animals… coyote, javelina, mountain lions – active at night • Air Mass – cT • Soil – light-colored, salty, thin due to lack of water Deserts Monument Valley, Utah • Climate… Average precipitation…low to moderate Biomes… Grasslands Average temperatures Extreme summer / winter temps! 4 seasons (temperate) • Plants… grasses dominate – thrive on fire • Animals… bison, wolves, prairie dogs (grazers) • Air Masses – mT and cP • Soil – temperate grasslands can be very rich (grainbelts) High Plains of Wyoming • Climate … Average precipitation - high (600 cm/yr) Average temperatures - constantly high • Plants… large leaves to capture sunlight • Animals… jaguar, tapirs, primates – many live in trees • Air Mass – mT • Soil – intensely weathered Biomes… Rainforests Climate Changes Ice Ages… What was the ice age? periods of extensive glacial coverage a. An interglacial interval is a warm period. b. We are currently in an interglacial period. Seasons… What causes the seasons? the tilt of the Earth as it orbits the sun (We are tilted towards the sun during our summer and away from the sun during our winter.) http://kennedy-outerspace.wikispaces.com/file/view/seasons.gif/168395377/seasons.gif http://www.galapagosonline.com/Galapagos_Natural_History/Oceanography/Currents.html El Niño What is El Niño? Warm ocean current that develops off W. coast of S. America & can cause shortterm, worldwide climatic changes Recent Major El Niño Years – 1982 and 1998 Change Can Be Natural… What type of studies provide evidence of past climatic changes? (Before thermometers, that is!) i. ii. iii. iv. tree rings ice-core samples fossils & pollen samples radio-carbon samples http://titlemn.com/wp-content/uploads/2010/01/tree-rings1.jpg Dendrochronology is the study of tree rings. Earth’s Orbit… When Earth’s orbit elongates to become more elliptical… it passes closer to Sun & temps rise or farther from Sun and temps fall http://grendelreport.posterous.com/ipcc-corruption-included-ignoring-facts-and-s http://www.cgrer.uiowa.edu/people/carmichael/atmos_course/ATMOS_PROJ_99/bilskemp/natural_variability.html Earth’s Tilt… If the angle of the tilt of Earth’s axis increased (nutation)… there would be more (or less) temp contrast b/tw summer & winter. Earth’s Wobble (precession)… When Earth wobbles towards the star Vega winters will be colder in the N. hemisphere. http://www.shiftoftheage.com/wp-content/uploads/2009/10/precession-earth-spintop.jpg Volcanoes Large volcanic eruptions tend to… cool the Earth. b/c volcanic ash & dust block solar radiation. Tambora, 1815 During El Niño pressure over… a. Western pacific increases b. Eastern pacific decreases Spotlight on El Niño Recent Major El Niño Years – 1982 and 1998 Trade winds weaken. (which causes warm water to flow back to S. America) Spotlight on El Niño Recent Major El Niño Years – 1982 and 1998 Warm equatorial current moves east towards S. America. a. Peru becomes warm and rainy. b. Australia experiences drought. Spotlight on El Niño Recent Major El Niño Years – 1982 and 1998 The jet streams experience a southern shift. a. California and the Gulf Coast… experience severe weather b. Fewer hurricanes in the Atlantic. (b/c of southern shift of the jet streams) Spotlight on El Niño Climate Change: Manmade or Natural? One Major Issue The issue of climate change is probably one of the most important of our day. No scientist questions that we have experienced warming and cooling lately. The question is the cause of the warming – is it caused by people releasing carbon dioxide into the atmosphere or by natural forces such as the sun and water vapor? There are two main groups of scientists – those who believe that climate change is manmade and those who believe that climate change is natural. Manmade Climate Change … Who’s On This Side? a. United Nations IPCC (Intergovernmental Panel on Climate Change) b. Al Gore (Former Vice President) c. James Hansen (NASA) Manmade Climate Change… Basic Belief About Cause of Climate Change… People are causing climate change by burning fossil fuels & it will cause catastrophic changes An Inconvenient Truth? Manmade Climate Change … The Role of Carbon Dioxide… Carbon dioxide is warming the atmosphere. CO2 is often referred to as “carbon emissions”. It is released by burning fossil fuels, Manmade Climate Change… Evidence to Support View? a. Carbon dioxide studies showing that levels have gone up. b. Climate studies represented by the discredited “hockeystick” graph c. Computer models showing extreme warming & results Manmade Climate Change… What to Do About Climate Change? 1. Reduce our use of fossil fuels (or buy carbon credits to offset usage) 2. Use alternative energy sources Natural Climate Change… Basic Belief About Cause of Climate Change… Climate’s always changed, it’s natural, & caused mostly by changes in the Sun’s output. Natural Climate Change… The Role of Carbon Dioxide… Carbon dioxide (CO2) is a trace greenhouse gas & not a major cause of warming. vs. A trace greenhouse gas or the Sun? Which is more powerful? Hmmmm… Natural Climate Change Evidence to Support View? a. Climate studies showing Medieval Warming & Little Ice Age b. Sunspot data showing global temps go up & down with sun spot activity c. Ice core data showing carbon dioxide (CO2) levels go up AFTER temps go up. 5. What to Do About Climate Change? Natural Climate Change Adapt for future changes! Continue the research & the debate Biodiversity Biodiversity The biosphere is… …all life on Earth! Biodiversity refers to … number & variety of species on Earth Genetic biodiversity is … difference in genetic makeup within a species. There are 1.6 million known species on earth. Most of these known species are insects! There are an estimated 11.4 million species yet to be discovered! www.istockphoto.com Biodiversity… a. The biome with the most biodiversity is… … rainforest b/c warm & lots of water available for living things b. The biomes with the least biodiversity are… … tundra b/c very cold & little liquid water available. … followed by the desert b/c least water available Factors That Reduce Biodiversity… Human Population Growth… As our population grows the demand for natural resources… … increases 75% of all species become extinct due to habitat loss. • (Why? If its habitat is destroyed, where will it live? What will it eat?) • A growing population demands more natural resources! Factors That Reduce Biodiversity… tpeblog.wordpress.com Habitat Alteration… Ecosystems with a high biodiversity are more stable b/c… … they can recover more quickly from harmful events such as disease and drought Habitat alteration … … changing of a natural habitat (in these examples, human-caused) … includes monoculture, deforestation, and urbanization Habitat Alteration a. Monoculture - planting just one species (Basically, one crop take the place of many species.) It decreases biodiversity & can lead to crop failure if disease wipes out the single plant species. Example – Palm oil plantations in Borneo http://wwf.panda.org http://earthobservatory.nasa.gov/Features/Deforestation/Images/slash_and_burn_children.jpg Habitat Alteration… Deforestation is the removal of trees without adequate replanting. … It reduces biodiversity b/c animals are left without homes and food (not to mention, people are also left homeless!) Example: This occurs in rain forests like Borneo around the world. Habitat Alteration Urban Development: People moving to urban areas reduces biodiversity … natural habitats are lost as forests are cleared & wetlands are filled … solid waste pollutes land, water, & air. Invasive Species… An invasive species is one that is not native to an area. Invasive species reduce biodiversity in one of two ways… – They have no natural enemies so they can take over an ecosystem. (Burmese python) – Native species have no defenses against an exotic species. Invasive species take over! This is kudzu…a local invasive species! Pollution… The major source of near-shore pollution … sewage water High levels of nitrogen and phosphorus in human wastewater creates... … blooms of algae that die & use up oxygen (O2) in water as they decompose (Remember eutrophication?) Pumping untreated sewage into the ocean creates… … large dead zones on ocean floor where there are no living organisms (example: Australia) Overharvesting… 1. Overharvesting is… … excessive fishing of aquatic animals … excessive harvesting plants 2. Examples of species that might be overharvested here in North Carolina are… … Ramps (wild leeks) … Fish such as bass …http://www.nytimes.com/2011/04/20/dining/20forage.h tml?pagewanted=all&_r=0 3. This leads to a reduction in biodiversity by… reducing population of harvested species. Global Impact… The loss of biodiversity affects our survival needs on a global scale! – – – – – Food Water Air Shelter Energy To prevent death, famine, exposure, and wars and to possibly find cures for diseases, and even prevent, we need to preserve biodiversity!