April 28, 2009 Global Warming PPT Volvo Factory W/S Short Video

Thousands of years ago Average temperature over past 900,000 years Average surface temperature (°C)

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

Temperature change (C°) Temperature change over past 1,000 years Year

Average surface temperature (°C) Year Average temperature over past 130 years

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.

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.

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.

Dai et al. J. Hydromet (2004)

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.

Human Contributions Growing livestock –Cows burp and fart---release methane NO2 from automobiles because of combustion engines Burning fossil fuels

Evidence of Global Warming?

BLEACHING OF CORAL REEFS BY OCEAN TEMPS > 85deg

The Severity of Storms is Increasing

15 Polar Ice Cap

Shepard Glacier Glacier National Park 2005 Photo by B. Reardon, USGS 1913 Photo by W.C. Alden, USGS

Global warming or not?

Transportation Choices THIS Or THIS

Energy choices Versus

Housing Choices

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