Climate Change…
and
Global Warming
Different Terms:
GLOBAL WARMING …a part of climate
change, it concerns the increase of the Earth’s average surface temperature
CLIMATE CHANGE …broader term
including many changes in climate, such as temperature, wind & ocean currents, precipitation.
CLIMATE CHANGETemperature
Currents
Precipitation
Key Questions
• Is the climate changing?
• If so, do the actions of humans contribute to the changes?
• If so, what can/should be done about these issues?
Key Questions
Who Studies?
Numerous Scientific Organizations
Leading University Researchers
Fossil Fuel Industry
Key Questions
What are the Most Relevant Areas of Science?
Climatology
Oceanography
Meteorology
Atmospheric Science
The Sides…Concerned or Alarmed
• Over 97% of climatologists, atmospheric scientists, oceanographers and meteorologists agree:
- The Earth is Warming
- Increased Greenhouse gases are the cause
Skeptics and Deniers
• Less than 3% of scientists in these key fields claim:
- The Earth may begetting warmer, but
- It is part of a natural climate cycleDO
SOMETHING NOW
DO NOTHING
Key Terms
• Solar Energy
• Radiation Cooling
• Greenhouse Gases
• Carbon Dioxide
Solar Energy
Solar Energy
Heats planet – without solar energy, Earth would be too cold
Plants use light from Sun to grow, and to produce the oxygen we breath
Radiation Cooling• radiational cooling (rā′dē-ā′shə-nəl)
- The cooling of the Earth's surface, occurring mostly at night.
- It is caused by the emission of infrared radiation from the Earth's surface, the tops of clouds, and the atmosphere.
- It is important in maintaining the Earth's energy balance.
Solar Energy and Radiation Cooling
Sun
Earth’s Temperature
Solar
Energy
RadiationCooling
Sun
Earth’s Temperature
Solar
Energy
RadiationCooling
Greenhouse Gases
Gases that trap heat in the
atmosphere are called greenhouse
gases.
Greenhouse Gases
How Global Warming Works
Fossil fuels (coal, oil, natural gas)
Carbon Dioxide (CO2)
The Sun’s energy passes through the car’s windshield.
This energy (heat) is trapped inside the car and cannot pass back through the windshield, causing the inside of the car to warm up.
Example of the Greenhouse Effect
The U.S. emits about 5.4 billion metric tons of greenhouse gases annually, 17.6 tons of CO2 per American.
Carbon dioxide stays in the atmosphere for approximately 100 years, methane lasts about 12 years.
As these gases continue to raise surface temperatures, they trigger the release of even more carbon dioxide and methane that are currently trapped in frozen Arctic permafrost and tundra soils, further increasing temperatures.
5.4 billion metric tons CO2/yr
These greenhouse gases last a long time…
Warming begets more warming…
A “feedback mechanism” …
CO2 Atmospheric Measurements
CO2 Measurements Since 1958 – Mauna Loa, Hawaii
Ice Core Data
CO2 Measurements Before 1958 - Antarctica
CARBON EMISSIONS BY COUNTRY (Millions of Tons in 2007)
DEFORESTATION
o PLANTS AND TREES ABSORB CO2
o PLANTS AND TREES EXHALE O2
o AS THE NUMBER OF PLANTS AND TREES ARE REDUCED, THERE IS A HIGHER CONCENTRATION OF CO2 IN THE ATMOSPHERE
ICE SURFACES
o ICE REFLECTS SOLAR ENERGY
o AS ICE MELTS, LAND AND WATER ABSORB MORE HEAT
o AS THE EARTH ABSORBS MORE HEAT, MORE ICE MELTS
Future Carbon Dioxide Levels
• Significant increases in CO2 emissions
– Massive development in China, India and other advancing nations
– Increased coal usage
Of all U.S. greenhouse gas emissions come from households:
• Vehicles
• Home Heating
• Electricity
Households are Big Contributors to Climate Change
Effects of Global Warming
So how can each of us slow global warming now?
What’s being done now to reduce our emissions?
Solar Power Wind Power Fuel-Efficiency
Because greenhouse gas emissions are tied very closely to our energy consumption, using less fossil fuel puts fewer greenhouse gases into the atmosphere.
Reduce Consumption of Fossil Fuels
Mountaintop removal for coal mining near Rawl, West Virginia.
50% of electricity in the United States is produced from coal.
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Small changes add up…
Replace your old refrigerator with a new Energy Star: Annual savings: $90; 700 pounds CO2
Set your thermostat down a few degrees in the winterAnnual savings: $135; 1400 pounds CO2
Wash clothes in cold water onlyAnnual savings: $70; 500 pounds CO2
Drive JUST 10 fewer miles per weekAnnual savings: $80; 520 pounds CO2
Reduce your garbage by 10% through greater recycling or reduced packagingAnnual savings: 1200 pounds CO2
Caulk and weather-strip around doors and windowsAnnual savings: $80; 650 pounds CO2