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Global Warming.


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Global Warming GLOBAL WARMING: Natural Greenhouse Effect Global Warming Controversy and GW Possible effects of GW Outline Sun and earth Sunlight warms earth's surface Heat radiates back into atmosphere Some heat reabsorbed in atmosphere Remainder radiates into space
Transcripts
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An unnatural weather change

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GLOBAL WARMING: Natural Greenhouse Effect Global Warming Controversy and GW Possible impacts of GW Outline

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Sun and earth Sunlight warms earth's surface Heat emanates over into climate Some warmth reabsorbed in air Remainder transmits into space

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EARTH'S ATMOSPHERIC LAYERS TROPOSPHERE 0 - 15 km above surface G.H. Impact happens here STRATOSPHERE 15 - 50 km above surface Ozone layer MESOSPHERE 50 - 80 km above surface "Middle sphere" IONOSPHERE/THERMOSPHERE 80 km and up

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ANSWER : The vitality's wavelength changes, and this is the purpose behind the distinction in section and way out To assist you with comprehension this present, we should look at wavelengths in more detail... Wavelength and GH Effect THE QUESTION : But in the event that the vitality went through the environment while in transit to the world's surface, why does it get caught in transit out ?

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l WAVELENGTH : Electromagnetic radiation (EMR) goes in waves Wavelength ( l ): separation starting with one wave peak then onto the next Shorter l = more vitality Fig. 3.7

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Note contrasts in l in approaching and active radiation Wien’s Law: l = 3 mm/T

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MOLECULES THAT TRAP HEAT IN G.H. Impact: Water vapor & little beads represent 97% of the characteristic GH impact H 2 O "Normal" levels of CO 2 in climate likewise contribute CO 2 Natural Greenhouse Gasses in air trap radiation at the long wavelength of active radiation, however not at the short wavelength of approaching radiation

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Absorbance by H 2 O and CO 2 is at l of discharged radiation, not approaching Incoming l = 0.1 - 1.5  m

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So what's the issue? HUMAN ACTIVITIES AFFECT SYSTEM : Affect framework so it traps more warmth than it ordinarily would This raises temperatures at the Earth's surface WHAT CAUSES THIS? (1.) Increasing CO 2 focuses in air, catching more warmth (2.) Adding different gasses ("greenhouse gases") to climate that likewise trap heat

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Adding CO 2 : Human Impacts WHAT ADDS CO 2 TO THE ATMOSPHERE? Smoldering fossil fills for vitality Combustion of coal, oil, and characteristic gas produces CO 2 Overwhelms framework's ability to expel CO 2 from environment CO 2 develops, traps more warmth, temperatures build

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Oil: 30% more CO 2 than nat. gas Coal: 43% more CO 2 than nat. gas Natural Gas: Lowest CO 2 Adding CO 2 : Human Impacts COMPARING THE FOSSIL FUELS? Which emanates the slightest CO 2 for every unit vitality delivered?

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CO 2 focuses subsequent to 1960

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QUESTION: Do expanding CO 2 fixations associate with higher temps? ANSWER: Yes, truly. This association is addressed by some however

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WHERE'S THE OTHER 40-half FROM? Other Greenhouse gasses other than CO 2 that trap heat Chlorofluorocarbons (CFCs) Methane (common gas) Nitrous Oxide (N 2 O) Greenhouse gasses GLOBAL WARMING: CO 2 emanations represent 50-60% of the anthropogenic (human-incited) temperature change

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METHANE (Natural Gas): 12-20 % of anthropogenic GW because of methane From regular gas spills, domesticated animals Concentrations as of now stable, yet high CHLOROFLUOROCARBONS (CFCs): 15-25 % of anthropogenic GW because of CFCs Used as coolants (freon), in the past as charges Atmospheric focuses developing by 5% yearly NITROUS OXIDE (N 2 O): 5 % of anthropogenic GW because of N 2 O From compost utilization, blazing coal, vehicle fumes Concentrations developing by 0.2% every year

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Greenhouse gasses PROBLEM #1: Compared to CO 2 atom, every particle of these gasses traps: CFCs: 1,500 - 7,000 times as much warmth Methane: 25 times as much warmth Nitrous Oxide: 230 times as much warmth PROBLEM #2: Trap heat in a wavelength not caught by CO 2

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Note 8-12  m window of absorbance

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Recapping NATURAL GREENHOUSE EFFECT: Natural catching of warmth by gasses in Earth's atmos. Permits life to persevere on earth GLOBAL WARMING: Human exercises quicken warmth catching Average worldwide temperatures ascend Due to CO 2 from fossil energizes, nursery gasses Global warming hypothesis is questionable Let's take a gander at the contention

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Controversy #1: Recent temp. change RECORDED DATA: Data just backpedals to 1860 Since 1860, temps have ascended around 0.9 o F (0.5 o C) This previous year (1999) was hottest on record THE CONTROVERSY: Some case temp. readings are off base because of "urban warmth island effect", and temps. aren't generally rising

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Controversy #2: Correlation between CO 2 and temp. PAST CLIMATE: Reconstruct past atmosphere from air pockets caught in icy masses. Finds CO 2 levels and temp. to be connected THE CONTROVERSY: CO 2 information strong, however temp. assessments are suspect. Battle there is no connection between CO 2 levels and temperatures

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Controversy #3: Predicting temperature changes CLIMATE MODELS: Create model of earth's climate, data variables and watch changes in the model. Proposes that normal temp. could rise 3.6 o F (2.0 o C) by 2100 THE CONTROVERSY: Climate models higher theoretical. Earth's atmosphere too complex to ever be displayed.

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What's the accord? HUMAN versus Common: Are present temp. builds human-incited or regular? Accord: At slightest mostly brought on by human exercises HOW MUCH WILL IT INCREASE? Agreement: Who knows? Earth's atmosphere just excessively mind boggling, making it impossible to be precisely displayed Assuming temperatures ascend of course, what might be the outcomes?

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Possible impacts of an unnatural weather change SEA LEVELS RISE: Rising temps. melt ice tops and reason seas to extend Together these outcome in higher ocean levels Could rise 19 in (48 cm) by 2100 Highly populated beach front ranges get to be unihabitable Arable area diminishes; less sustenance creation Wealthy nations construct embankments, poor nations surge

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American breadbasket gets to be Canadian breadbasket Global yields down 10-70% Possible impacts of a dangerous atmospheric devation GRAIN BELT SHIFT: Crops (corn, wheat, and so on.) develop ideally at temps in Midwest U.S. Midwest gets to be hotter, ideal temp. reach moves northward

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Possible impacts of a dangerous atmospheric devation EXTREME WEATHER: Temperature drives climate designs Higher normal temps. means more amazing climate (surges, dry season, high/low temps.) Some are thinking about whether ebb and flow climate extremes are because of environmental change

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Ocean "conveyor belt" - could separate if sea temperatures lift an excess of

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What would it be advisable for us to do now? THREE SCHOOLS OF THOUGHT: Nothing: Contend GW is a lie and exaggerated. No activity is fundamental Wait and see: Need more complete examination to connection human exercises with temperature increments. Concentrate now and act later. Safety oriented system: Act now, while you have the shot. Examination will never demonstrate association so why hold up?

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International bargains on GW KYOTO, JAPAN (DEC. 1997) Treaty calls for decreases in CO 2 , methane, nitrous oxide, and three others that harm ozone 38 industrialized countries needed to lessen their emanations from 1990 levels by 2012. E.U.  8%; U.S.  7%, Japan  6% Developing nations, including China and India, would have willful limits, no set guidelines

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WHY? Diminishments cost cash in transient Economy could endure fleeting Global contenders like China have advantage International bargains on GW KYOTO, JAPAN (DEC. 1997) Bush Administration declines to sign it. Will it ever pass? Not likely. .:tslides