Global Climate Change

Global Climate Change

http://www.msss.com/earth/earth.gif

Global Warming:What do you

already know about global warming?

How do you feel about global warming?

Grinnell Glacier in Glacier National Park,http://www.nrmsc.usgs.gov/repeatphoto/Pairs/Grinnell/

Grinnell_Mt_Gould/Grinnellquad_frMtGould_c-t.jpg

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.

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.

The Greenhouse Effect:

http://www.crystalinks.com/greenhouse2.gif

Another Diagram showing

the Greenhous

e Effect:

http://www.umich.edu/~gs265/society/greenhouse.htm

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, CO2

– Nitrous Oxide, N2O– Methane, CH4

– Ozone, O3

– Water Vapor, H2O

Greenhouse Gases Continued:

These greenhouse gases are produced by human-activity:– Halocarbons– Chlorine and Bromine containing substances

(examples: chlorofluorocarbons, CFCs)– Sulfur hexafluoride, SF6

– Hydrofluorocarbons, HFCs– Perfluorocarbons, PFCs

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 CO2, some CH4 from mining and natural gas)

http://www.sciencenewsforkids.org/articles/20041208/a610_3857.jpg

http://longislandnn.org/images/smog.jpg

Human Influence on Greenhouse Gases Continued …

2. Removing and burning vegetation

- Leads to fewer plants so that means less CO2 can be pulled from the air.

http://www.plu.edu/~hoodbs/img/deforestation-2.jpg

Human Influence on Greenhouse Gases Continued …

3. Industrial actions

http://www.speedrack.net/mill.jpg

http://www.workforceboardsmetrochicago.org/upload/manufacturing_pic.jpg

http://www.reliablebiopharm.com/images/manufacturing-biotech-center.gif

- Release CO2 directly (coolants, combustion, etc.) or use LOTS of energy (which is primarily generated by burning fossil fuels).

How do scientists gather data about CO2 levels?

• Current and recent data collection occurs worldwide – on land, in oceans and via satellite.

Map showing locations of

current LAND measurements:

http://oceanworld.tamu.edu/resources/oceanography-book/evidenceforwarming.htm

How do scientists determine the temperature and CO2 levels of the past?

1. Ice cores from thick ice sheets in Greenland, Antarctica, and mountain glaciers worldwide. http://oceanworld.tamu.edu/resources/oceanography-book/evidenceforwarming.htm

Air bubbles trapped in the ice give atmospheric gas content (concentration of CO2)

For information before 150 years ago, scientists gather indirect data from many climatic indicators:

Gathering Past CO2 Data:Additional methods – used in addition to the ice cores:

2. 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

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Greenhouse Gas Levels(Last 1000 years)

http://www.research.noaa.gov/climate/images/observing3.gif

Worldwide Temperature(Over the same time period)

http://www.washingtonpost.com/wp-dyn/content/graphic/2006/06/23/GR2006062300505.html?referrer=emaillink

How long does CO2 remain in the atmosphere?

• CO2 remains in the atmosphere for 50-200 years.

Compare that with how long other greenhouse gases remain in the atmosphere:

• CH4 remains in the atmosphere for 10-15 years.

• H2O remains in the atmosphere for days.

• CFCs and HFCs remain in the atmosphere for 100 years.

Evidence of Climate Change:

1. Glacier reduction!Locations of Glaciers Worldwide (in white):

http://www.worldviewofglobalwarming.org/pages/glaciers.html

1875:

2004:

Pasterze, Austria’s longest glacier (lost 2 km in the last century):

Video Clip of North Pole Ice Breaking Up

Evidence of Climate Change …2. Sea Level Rising!

http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/04/sci_nat_climate_change___evidence_and_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

Evidence of Climate Change …3. Spread of Tropical

Diseases into new territory!

http://www.idph.state.il.us/images/wnv_spread_time.jpg

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”http://www.reeffutures.org

Coral Reef Bleaching Video Clip

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:

http://www.panda.org/about_wwf/what_we_do/climate_change/problems/impacts/species/turtles/index.cfm

Polar bears have a decreasing range:

http://www.panda.org/about_wwf/what_we_do/climate_change/problems/impacts/species/polar_bears/index.cfm

Mosquitoes have an increasing range:

http://www.michigan.gov/images/mosquito_65147_7.jpg