2. 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?
3. 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
4. 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
12. The U.S. emits about 6.4 billion metric
tons of greenhouse gases annually, 25%
of the world’s total.
Carbon dioxide stays in the
atmosphere for approximately
100 years, methane lasts about
12 years. Other greenhouse
gases last even longer.
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.
…potentially causing “runaway global warming”.
6.4 billion metric tons
CO2/yr
These greenhouse gases last a
long time…
Warming begets more warming…
A feedback mechanism ensues…
14. Annual Carbon Emissions
Annual carbon emissions
Atmospheric CO2
Atmospheric CO2 average
1955 1965 1975 1985 1995 2005
0
4
6
8
2
Year
Carbon(109
metrictons)
15. 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)
16. Of all U.S. greenhouse gas
emissions come from
households:
• Vehicles
• Home Heating
• Electricity
Households are Big Contributors to Climate Change
17. So how can each of us slow
global warming now?
18. 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.
Reduce our consumption of fossil fuels
Mountaintop removal for
coal mining near Rawl,
West Virginia.
50% of electricity in the
United States is produced
from coal.
(
19. 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
20. Small changes really 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 winter
Annual savings:
$135; 1400 pounds CO2
Wash clothes in cold water only
Annual savings:
$70; 500 pounds CO2
Drive JUST 10 fewer miles per week
Annual savings:
$80; 520 pounds CO2
Reduce your garbage by 10%
through greater recycling or reduced
packaging
Annual savings:
1200 pounds CO2
Caulk and weather-strip around doors
and windows
Annual savings:
$80; 650 pounds CO2
*
These are mid-range estimates from
published sources; your savings may vary.
21. do as I say to protect the earth
Each of us must take steps to protect
our Earth's climate.
Editor's Notes
In examining global warming, we will be looking at questions such as
Is the world getting warmer?
If so, are the actions of mankind to blame for earth’s temperature increases?
What can or should be done about global warming?
Are the potential resolutions to global warming worth the cost to implement them?
This is a big picture examination of the earth’s climate
The Earth was formed around 4.6 billion years ago
And was originally very hot
However, the Sun’s energy output was only 70% of what it is presently
Liquid water was present on the surface around 4.3 billion years ago
The first life forms appeared ~3.8 billion years ago
Photosynthesis began 3.5-2.5 billion years ago,
which produced oxygen and removed carbon dioxide and methane, which are greenhouse gases, from the atmosphere
As a result, the Earth went through periods of cooling, commonly referred to as “Snowball Earth” and subsequent warming
Earth began its current cycles of glacial and interglacial periods around 3 million years ago
The temperature of the earth is directly related to the energy input from the Sun. Some of the Sun’s energy is reflected by clouds. Other is reflected by ice. The remainder is absorbed by the earth.
If amount of solar energy absorbed by the earth is equal to the amount radiated back into space, the earth remains at a constant temperature.
However, if the amount of solar energy is greater than the amount radiated, then the earth heats up.
If the amount of solar energy is less than the amount radiated, then the earth cools down.
To a certain degree, the earth acts like a greenhouse. Energy from the Sun penetrates the glass of a greenhouse and warms the air and objects within the greenhouse. The same glass slows the heat from escaping, resulting in much higher temperatures within the greenhouse than outside it.
Likewise, the earth’s atmospheric gases affect the ability of the earth to radiate the Sun’s energy back into space. Nitrogen and Oxygen make up 99% of the earth’s atmospheric gases and are non-greenhouse gases. Water, Carbon Dioxide, and Methane make up 1% of the earth’s atmosphere, but are greenhouse gases, since they cause the earth to retain heat.
This spike is due to the exponential increase in the use of fossil fuels over the last 150 years. Shown here are emissions of carbon from gas, solid, liquid fuels, and the total carbon emissions.
Despite this rapid increase in carbon emissions, only about half the carbon can be detected in the atmosphere. The remainder of the carbon dioxide is being dissolved in the oceans or incorporated into trees.
Future Carbon Emissions
will probably increase, especially in China and developing countries
This will result in a likely doubling of carbon dioxide levels within 150 years, due to
Increased coal usage
And increased natural gas usage,
although petroleum usage is likely to decrease due to increased cost and decreasing supply
