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Is Global Climate Change Happening?

Weather vs Climate

• Weather: atmospheric conditions in any given place over a short term.(i.e. Today will be dry and 95 degrees F)

• Climate: average weather conditions in a region over a long period of time.(i.e. Dry season in the southwest)

Global Warming or Climate Change?

• Global Warming – Increase in the Earth’s average temperature (i.e. an increase of 1 degree F)

• Global Climate Change – Change in average weather conditions in a region over a long period of time(i.e. increase or decrease; temperature, precipitation, humidity, storms)

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The Climate System

NOAA Slides by Forecast Systems Laboratory.

System – A set of parts that interact or work with each other

The climate system is affected by:

Hydrosphere Distribution

Hydrosphere – all of Earth’s water (solid, gas & liquid). Oceans store and

release Carbon Dioxide or CO2

Cryosphere - all solid water; sea ice, glaciers – Albedo or reflect Sun’s energy

http://www.google.com/imgres?imgurl=http://www.the-m-factory.com

Biosphere: all life; trees & plants – use, store and release CO2 (carbon

dioxide)

http://www.google.com/imgres?imgurl=http://www.isavo.com

Atmosphere – gaseous layer surrounding Earth – clouds exert a

cooling effect that slows the evaporation of water

http://www.google.com/imgres?imgurl=http://www.pacificislandtravel.com

Anthrosphere – what humans build; we burn fossil fuels which releases CO2

The Greenhouse Effect

• The sun’s energy enters the atmosphere and warms the Earth. Our planet’s atmosphere traps the heat energy.

• Some of the sun’s energy is reflected back into space but the remainder is absorbed by greenhouse gases in the atmosphere where they help to warm the planet.

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Without this natural phenomenon our planet would be 60 degrees F colder Living things need a temperature of 32-212°F (0-100°C) to survive.

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Greenhouse Gases: Carbon Dioxide

Sources of carbon dioxide emissions are:Land plants use CO2 from the atmosphere and return it when they dieAquatic plants use CO2 from the water and return it when they die

http://www.google.com/imgres?imgurl=http://www.geos.ed.ac.uk

Oceans and forests are carbon sinks which take in more carbon than they release.

Burning of forests or fossil fuelsemits CO2 to the atmosphere

Animal and plant respiration emits CO2 into the environment

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Greenhouse Gases: Methane

NOAA Slides by Forecast Systems Laboratory.

Greenhouse Gases: Methane

• Most of the methane emissions are from landfills

• Other sources are livestock and fossil fuel production

http://www.google.com/imgres?imgurl=http://herbarium.usu.edu/fungi/funfacts/

Greenhouse Gases: Summary

• The major greenhouse gas is CO2 but methane is more potent.

• The other major gases are water vapor and nitrous oxide.

1.9% 5.8%

10.0%

82.3%

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1996 Total U.S. Greenhouse Gas Emissions

Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 - 1996. U.S. EPA publication #236-R-98-006

Carbon Dioxide

Hydroflourocarbons (HFCs), perflourocarbons (PFCs), and Sulfur hexaflouride (SF6)

Nitrous Oxide

Methane

Atmospheric Concentrations of CO2 Mauna Loa, Hawaii 1959-1992

Source: Trends’93 A Compendium of Data on Global Change, Oak Ridge National Laboratory, Publication no. ORNL/CDIAC-65. Mauna Loa data from C.D. Keeling and T. Whorf

290

300

310

320

330

340

350

360

1959

1963

1967

1971

1975

1979

1983

1987

1991

Years

An

nual

Con

cent

rati

ons

of C

O2 Z

(ppm

v)

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Ozone depletion vs. Greenhouse Effect

• Ozone depletion is caused by the release of CFC’s (chlorofluoro-carbons) which break down the ozone layer.

• The ozone layer protects us from harmful radiation and gamma rays from the sun.

• Climate change due to the increasing amount of greenhouse gases is a different problem than ozone depletion.

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How Do We Take the Earth’s Temperature?

Weather stations track temperature, rainfall/precipitation, wind speed, and barometric pressure on land.

Ocean buoys take measurements at sea.

Satellites and weather balloons take measurements in the lower atmosphere.

Air bubbles in ice core samples provide information of the air composition (CO2) and temperature throughout Earth’s past.

http://www.google.com/imgres?imgurl=http://earthobservatory.nasa.gov

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CO2 measurements from the ice cores at the South Pole over 1000 yearsand direct measurements in Hawaii over 150

years

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Global temperatures are increasing

NOAA Slides by Forecast Systems Laboratory.

Climate Models - Climate change is a natural process; periods of colder and

warmer climates

• Ice age - 6 degrees F colder

• Land ice melts, rise in sea levels, mass extinctions - 6 degrees F warmer

Scientists predict the earth will warm an additional 2-6 degrees F by the year 2100

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• Scientists suggest that humans are influencing global climate change due to data that population increases match the increases in greenhouse gases.

How Humans Influence Climate Models

NOAA Slides by Forecast Systems Laboratory.

Climate Change Evidence

1. Atmospheric gases of CO2, N2O, Methane and Water Vapor are increasing at a rapid rate.

2. Global temperature has increased by 1 degree F in the past century.

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Weird Weather: Global Warming

3. Extreme weather; more frequent hurricanes, droughts, and floods.

• El Nino refers to above normal surface

temperatures in the Pacific Ocean that cause easterly winds to weaken. The cold water is unable to rise to the surface of the ocean. This interaction affects weather around the world, Australia experiences droughts while USA and Peru experience floods.

• La Nina is below normal sea surface temperatures.

4. Land and sea ice are melting – decreasing Albedo• Ocean levels are rising, (melting

land ice) submerging islands and eroding land.

• Salt water invades (salinity rates) and changes the fresh water ecosystems.

• Warm water holds less oxygen which can suffocate organisms or organisms migrate disrupting the food web for other organisms. WHY?

• The warmer water prevents mixing of nutrients and organisms found in colder waters. This is referred to as an “ocean desert” and in total is the size of Asia.

• The warm water also can shut down the ocean conveyor system which cycles water on our planet.

5. Changes in biome boundaries or disappearance of habitats; i.e. forests disappearing impacts variety of species, tundra permafrost, coral bleaching

6. Impacts on organisms; extinction rates increase - changes too fast for plants and animals to adapt, different migrating or nesting patterns

 7. Increase in disease carrying mosquitoes in once colder areas 8. Economic effects – damages from sea level rise or severe

storms

18NOAA Slides by Forecast Systems Laboratory.

Are Humans Changing the Climate?Similarities between temperature and CO2

levels

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U.S. Emissions

NOAA Slides by Forecast Systems Laboratory.

Each year, each person in the USA adds 20 tons of CO2 to the atmosphere (roughly the mass of 4 elephants or 40,000 pounds)

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CO2 Emissions From Fossil Fuel Combustion: 1996

0

1000

2000

3000

4000

5000

6000

Source: CO2 Emissions from Fuel Combustion 1971 - 1996, International Energy Agency, page II.4-5, 1998 Edition

Mill

ion

Ton

nes

of C

O2

USA is the leading producer of CO2

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CO2 Emissions Per Person: 1996

Mill

ion

Ton

nes

of C

O2

Source: CO2 Emissions from Fuel Combustion 1971 - 1996, International Energy Agency, page II.53-55, 1998 Edition

0

5

10

15

20

25

United S

tates

Canad

a

Germ

any

Russia

United K

ingd

om Japan

South

Afri

ca

Mex

ico

People'

s Rep

. Of C

hina

India

21NOAA Slides by Forecast Systems Laboratory.

Human activities that contribute greenhouse gases to the atmosphere:

Electricity-burn fossil fuels

Transportation – burn fossil fuels

Cutting and burning forests

Increase in human population/demand

Waste in landfills

Livestock waste

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Why Should We Care?

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What Can We Do About Global Climate Change?

What Can We Do About Climate Change?Reduce, Reuse, Recycle

Public Transportation, Efficient Cars, Carpool, Bike, Walk

Plant trees and Preserve Forests

Conserve electricity, turn off appliances & lights when not in use

Use renewable sources of energy

Buy local products

Use fluorescent light bulbs

Use Energy Star Products – Appliances, Windows, Heating/Cooling

Review: Matching

• Global Warming

• Global Climate

Change

• Greenhouse gases

• Absorb sun’s energy and emit energy in our atmosphere

• Change in average weather conditions in a region over a long period of time

• Increase in the Earth’s average temperature

Review: Matching• Human construction

(everything we build)

• Includes all of the water on the Earth

• All life on Earth

• The gaseous layer that surrounds the Earth

•Atmosphere

•Biosphere

•Anthrosphere

•Hydrosphere

Which 2 factors are the largest contributors to GCC?

• Burning Forests

• Landfills

• Ozone Depletion

• Burning Fossil Fuels

• Farming

• Industry

• Breathing

What happens with warm temps?

Oceans

• Levels• Oxygen• Molecules

• Ice

• Albedo• Light changes