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Global Climate Change

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Presentation on theme: "Global Climate Change"— Presentation transcript:

1 Global Climate Change http://


3 Global Climate Change: Pictures taken from same location during same time of year over a number of years… Grinnell Glacier in Glacier National Park, Grinnellquad_frMtGould_c-t.jpg

4 The Greenhouse Effect: The greenhouse effect is the process by which the atmosphere warms the Earth. First discovered in the early 1800s, the greenhouse effect describes both the natural process of heating Earth and the added effect of human action.

5 The Science Behind the Greenhouse Effect: Solar radiation from the Sun passes through Earth’s atmosphere. This light is absorbed by land and water and heats Earth’s surface. Some of that heat is emitted back into space as radiant heat. Some of this radiant heat is absorbed by gases in the atmosphere. These greenhouse gases re-emit the heat to lower parts of the atmosphere and to the surface of Earth.

6 The Greenhouse Effect: house2.gif

7 Another Diagram showing the Greenhouse Effect: e.htm

8 Greenhouse Gases: The gases found in the atmosphere that can absorb the radiant heat from Earth’s surface are called greenhouse gases: These are produced naturally and by human activities: –Carbon Dioxide, CO 2 –Nitrous Oxide, N 2 O –Methane, CH 4 –Ground-level Ozone, O 3 –Water Vapor, H 2 O

9 Greenhouse Gases Continued: These greenhouse gases are produced solely by human-activity: –Halocarbons –Chlorine and Bromine containing substances (examples: chlorofluorocarbons, CFCs) –Sulfur hexafluoride, SF 6 –Hydrofluorocarbons, HFCs –Perfluorocarbons, PFCs

10 Human Influence on Greenhouse Gases: 1.Burning fossil fuels Gasoline in vehicles and natural gas and coal in electricity generation THIS GENERATES THE MOST GREENHOUSE GASES! (primarily CO 2, some CH 4 from mining and natural gas)

11 Human Influence on Greenhouse Gases Continued … 2.Removing and burning vegetation - Leads to fewer plants so that means less CO 2 can be pulled from the air.

12 Human Influence on Greenhouse Gases Continued … 3. Industrial actions http://www.workforceboardsmetro _pic.jpg manufacturing-biotech-center.gif - Release CO 2 directly (coolants, combustion, etc.) or use LOTS of energy (which is primarily generated by burning fossil fuels).

13 How do scientists gather data about CO 2 levels? Current and recent data collection occurs worldwide – on land, in oceans and via satellite. Map showing locations of current LAND measurements:

14 How do scientists determine the temperature and CO 2 levels of the past? 1. Ice cores from thick ice sheets in Greenland, Antarctica, and mountain glaciers worldwide. Air bubbles trapped in the ice give atmospheric gas content (concentration of CO 2 ) For information before 150 years ago, scientists gather indirect data from many climatic indicators:

15 Gathering Past CO 2 Data: 2.Mud cores of ocean floor – showing climate variability over millions of years 3.Dendrochronology (using measurements of tree rings) – showing climate variability over hundreds of years 4.Pollen analysis (deposited in sediments) – showing climate variability over thousands of years 71640C1257230004FBBE2/$file/dendrochronology.jpg?OpenElement

16 Modeling our Future Climate ov/vision/earth/everydaylife/climate_class.html&docid=_wOGkbfm3AUTcM&imgurl= &ei=z6bzTv78DYyltwfAsJTQBg&zoom=1&iact=rc&dur=267&sig=106526677276316862996&page=2&tbnh=112&tbnw=173&start=13&ndsp=15&ved=1t:429,r:9,s:13&tx=75&ty=61 &surl=1

17 Greenhouse Gas Levels (Last 1000 years) rving3.gif

18 Worldwide Temperature (Over the same time period)

19 How long does CO 2 remain in the atmosphere? CO 2 remains in the atmosphere for 50-200 years. Compare that with how long other greenhouse gases remain in the atmosphere: CH 4 remains in the atmosphere for 10-15 years. H 2 O remains in the atmosphere for days. CFCs and HFCs remain in the atmosphere for 100 years.

20 Evidence of Climate Change: 1. Glacier reduction! Locations of Glaciers Worldwide (in white): 1875: 2004: Pasterze, Austria’s longest glacier (lost 2 km in the last century): Video Clip of North Pole Ice Breaking Up Video Clip of Effects of Glacier Reduction

21 Evidence of Climate Change … 2.Sea Level Rising! predictions/img/3.jpg - Over the past 100 years, the global sea level has risen by about 10-25 cm. Coastal erosion is even faster than sea level rise – which can destroy near-ocean structures. Jet Propulsion Laboratory, NASA Video Clip showing effects of rising sea level in an Indian coastal village

22 Evidence of Climate Change … 3.Spread of Tropical Diseases into new territory!

23 Evidence of Climate Change … 4. Coral Reef Bleaching! Coral Reefs are some of the most productive ecosystems on Earth. -Higher water temperature causes coral to lose its symbiotic algae (which provide nutrition and color to the coral) - When the algae die, coral appears white or “bleached” Coral Reef Bleaching Video Clip

24 Evidence of Climate Change … 5. Changing ranges of world’s species! - Ranges may be increasing or decreasing depending on the environmental needs of the species! Hawksbill turtles have a decreasing range: ex.cfm Polar bears have a decreasing range: ange/problems/impacts/species/polar_bears/index.cfm Mosquitoes have an increasing range:

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