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April 28, 2009 Global Warming PPT Volvo Factory W/S Short Video
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Thousands of years ago Average temperature over past 900,000 years Average surface temperature (°C)
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Average temperature over past 10,000 years = 15°C (59°F) Temperature change (C°) Temperature change over past 22,000 years Agriculture established End of last ice age Years ago
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Temperature change (C°) Temperature change over past 1,000 years Year
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Average surface temperature (°C) Year Average temperature over past 130 years
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How Do We Know What Temperatures Were in the Past? Scientists analyze tiny air bubbles trapped in ice cores learn about past: –temperature trends. –greenhouse gas concentrations.
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How Do We Know What Temperatures Were in the Past? In 2005, an ice core showed that CO 2 levels in the atmosphere are the highest they have been in 650,000 years.
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The Natural Greenhouse Effect Three major factors shape the earth’s climate: –The sun. –Greenhouse effect that warms the earth’s surface because of the presence of greenhouse gases. CO2, NO2, methane –Oceans store CO 2 and heat, evaporate and receive water, move stored heat to other parts of the world.
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Dai et al. J. Hydromet (2004)
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Major Greenhouse Gases Increases in average concentrations of three greenhouse gases in the atmosphere between 1860 and 2004, mostly due to fossil fuel burning, deforestation, and agriculture.
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Human Contributions Growing livestock –Cows burp and fart---release methane NO2 from automobiles because of combustion engines Burning fossil fuels
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Evidence of Global Warming?
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BLEACHING OF CORAL REEFS BY OCEAN TEMPS > 85deg
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The Severity of Storms is Increasing
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15 Polar Ice Cap
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Shepard Glacier Glacier National Park 2005 Photo by B. Reardon, USGS 1913 Photo by W.C. Alden, USGS
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Global warming or not?
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Transportation Choices THIS Or THIS
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Energy choices Versus
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Housing Choices
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VOLVO
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