Introduction
• Is the world getting warmer?
• If so, are the actions of mankind to blame for earth’s temperature increases? • What can/should be done about these issues? History of Earth’s Climate
• Earth formed ~4.6 billion years ago
• Originally very hot
• Sun’s energy output only 70% of present • Liquid water present ~4.3 billion years
History of Earth’s Climate
• Life appeared ~3.8 billion years ago
• Photosynthesis began 3.5-2.5 billion years ago – Produced oxygen and removed carbon dioxide and methane (greenhouse gases)
– Earth went through periods of cooling
(“Snowball Earth”) and warming
• Earth began cycles of glacial and interglacial periods ~3 million years ago
The U.S. emits about 6.4 billion metric tons of greenhouse gases annually, 25% of the world’s total.
6.4 billion metric tons
CO2/yr
These greenhouse gases last a long time…
Carbon dioxide stays in the atmosphere for approximately
100 years, methane lasts about 12 years. Other greenhouse gases last even longer. Warming begets more warming…
As these gases continue to raise surface temperatures, they trigger the release of even greater quantities of carbon dioxide and methane that are currently trapped in frozen Arctic permafrost and tundra soils, further increasing temperatures. A feedback mechanism ensues…
…potentially causing “runaway global warming”.
Carbon (109 metric tons)
Worldwide Carbon Emissions
8
7
6
5
Total
Liquid fuel
Solid fuel
Gas fuel
4
3
2
1
0
1750
1800
1850
1900
Year
1950
2000
Carbon (109 metric tons)
Annual
Carbon
Emissions
8
6
Annual carbon emissions
Atmospheric CO2
Atmospheric CO2 average
4
2
0
1955
1965
1975
1985
Year
1995
2005
Future Carbon Dioxide
Levels
• Increasing CO2 emissions, especially in China and developing countries
• Likely to double within 150 years:
– Increased coal usage
– Increased natural gas usage
– Decreased petroleum usage (increased cost and decreasing supply)
Households are Big Contributors to Climate Change
Of all U.S. greenhouse gas emissions come from households: • Vehicles
• Home Heating
• Electricity
So how can each of us slow global warming now?
Reduce our consumption of fossil fuels
Because greenhouse gas emissions are tied very closely to our energy consumption, using less fossil fuel based energy puts fewer greenhouse gases into the atmosphere.
This will help slow global warming.
Mountaintop removal for coal mining near Rawl,
West Virginia.
50% of electricity in the
United States is produced from coal.
(
Average Electricity Emission
Factors
Region/State CO2 lb/kWh CO2 tons/MWh CO2 Metric tons/MWh CH4 lbs/MWh NO2 lbs/MWh
South Atlantic 1.35 0.674
0.612
0.0127 0.0207
North Carolina 1.24 0.621
0.563
0.0105 0.0203
Virginia
1.16 0.582
0.528
0.0137 0.0192
West Virginia 1.98 0.998
0.897
0.0137 0.0316
Kitchen Light Fixture
Three 60 Watt Bulbs
How much energy are those bulbs using?
1
2
Wattage
# of of the bulbs bulbs
3 bulbs (CFL bulbs)
18 W
Watts
Used
(Wattage x number of bulbs)
4
3 bulbs 180 W
6
days )
10 hours a day 18 x3
54 W
5
Watts
Watts Used hours /
(#3) x Total
Hours used year Hours
/day
per day
(#5 x 365
(#4)
(60 x 3)
(Incandescent bulbs) 60 W
3
10 hours a day 7
Kilowatt
hours / year (1000Wh =
1kWh)
(divide #6 by 1000)
(180 x 10)
(1800 x 365)
(640,800/10
00)
1800
Wh/day
640,800
Wh/ year
640.8 kWh per year 54 x 10
540x365
197,100
540
Wh/day
197,100
Wh/day
1000
197.1
kWh/yr
3 BULB REPLACEMENT EMISSION and COSTCOMPARISON
INCANDES
CENT vs. COMPACT FLUORESCENT
