2. Introduction
ïIs the world getting warmer?
ïIf so, are the actions of mankind to blame for
earthâs temperature increases?
ïWhat can/should be done about these issues?
3. History of Earthâs Climate
ïEarth formed ~4.6 billion years ago
ïOriginally very hot
ïSunâs energy output only 70% of present
ïLiquid water present ~4.3 billion years
4. History of Earthâs Climate
ïLife appeared ~3.8 billion years ago
ïPhotosynthesis began 3.5-2.5 billion years
ago
ïProduced oxygen and removed carbon
dioxide and methane (greenhouse gases)
ïEarth went through periods of cooling
(âSnowball Earthâ) and warming
ïEarth began cycles of glacial and interglacial
periods ~3 million years ago
13. Households are Big Contributors to Climate Change
Of all greenhouse gas
emissions come from
households:
âą Vehicles
âą Home Heating
âą Electricity
14. Our reliance on cars that burn fossil fuels is
one of the major causes of increased levels
of carbon dioxide in the atmosphere and it is
the primary cause of urban smog.
15. Facts about Global Warming
ïThe world emits about 25.6 billion metric tons of
greenhouse gases annually.
ïThese greenhouse gases last a long time.
ïThe amount of oxygen dissolved in the oceans
may decline.
ïWarming begets more warming.
19. Future Carbon Dioxide Levels
ï Increasing CO2 emissions, especially in China and
developing countries
ï Likely to double within 150 years:
ïIncreased coal usage
ïIncreased natural gas usage
ïDecreased petroleum usage (increased cost and
decreasing supply)
20. So how can each of us
slow global warming now?
21. Reduce our consumption of fossil fuels
âąBecause 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.
âą50% of electricity in the United States is produced
from coal.
(
22. We can make some simple substitutions
âąReplacing just 1 incandescent light bulb with 1
compact florescent bulb saves about 150 pounds of
carbon dioxide per year!
âąIf every household replaced
just 5 high-use incandescent
bulbs with compact florescent
lights we'd collectively save
more than $8 billion each year
in energy costs and we would
prevent the greenhouse gases
equivalent to the emissions
from nearly 10 million cars.
Source: http://www.energystar.gov
23. Small changes really add up
Drive JUST 10 fewer miles
per week
Annual savings:
520 pounds CO2
Replace your old
refrigerator with a new
Energy Star:
Annual savings:
700 pounds CO2
Wash clothes in cold water
only
Annual savings:
500 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:
650 pounds CO2
These are mid-range estimates from
published sources; your savings may vary.
*
24. Easy Solutions
ïTurning off lights saves
energy and money.
ï The more energy used,
the more rivers are
dammed or more fossil
fuel is burned, causing air
pollution and increased
levels of carbon dioxide in
the atmosphere.
25. ï Making paper and plastic bags
uses energy and resources.
ï The bags add to our litter and
waste problems, and plastic is not
biodegradable.
ï Recycling is not the best answer
because collecting and recycling
materials requires energy.
ï Instead, carry a reusable cloth bag
or a knapsack with you.
In examining global warming, we will be looking at questions such as ïž
Is the world getting warmer? ïž
If so, are the actions of mankind to blame for earthâs temperature increases? ïž
What can or should be done about global warming? ïž
Are the potential resolutions to global warming worth the cost to implement them? ïž
This is a big picture examination of the earthâs climate ïž
The Earth was formed around 4.6 billion years ago ïž
And was originally very hot ïž
However, the Sunâs energy output was only 70% of what it is presently ïž
Liquid water was present on the surface around 4.3 billion years agoïž
The first life forms appeared ~3.8 billion years ago ïž
Photosynthesis began 3.5-2.5 billion years ago, ïž
which produced oxygen and removed carbon dioxide and methane, which are greenhouse gases, from the atmosphere ïž
As a result, the Earth went through periods of cooling, commonly referred to as âSnowball Earthâ and subsequent warming ïž
Earth began its current cycles of glacial and interglacial periods around 3 million years ago ïž
The temperature of the earth is directly related to the energy input from the Sun. ïž Some of the Sunâs energy is reflected by clouds. ïž Other is reflected by ice. The remainder is absorbed by the earth. ïž
ïž 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. ïž
ïž However, if the amount of solar energy is greater than the amount radiated, then the earth heats up. ïž
ïž If the amount of solar energy is less than the amount radiated, then the earth cools down. ïž
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980
To a certain degree, the earth acts like a greenhouse. ïž 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. ïž
Likewise, the earthâs atmospheric gases affect the ability of the earth to radiate the Sunâs energy back into space. ïž
Nitrogen and ïž Oxygen ïž make up 99% of the earthâs atmospheric gases ïž and are non-greenhouse gases. ïž Water, ïž Carbon Dioxide, ïž and Methane ïž make up 1% of the earthâs atmosphere, ïž but are greenhouse gases, since they cause the earth to retain heat. ïž
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.
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 ïž gas, ïž solid, ïž liquid fuels, and ïž the total carbon emissions. ïž
Malaria and cholera increase, due to temperature increase
Shifting flora and fauna to different areas. Extinction of some species.
More extreme climates in inland locations. More frequent and devastating hurricanes.
Reduced snow cover in some areas. Glaciers melt in Antarctica.
Reduction of areas suitable for human habitation, for example. lowland Bangladesh.
Future Carbon Emissions ïž
will probably increase, especially in China and developing countries ïž
This will result in a likely doubling of carbon dioxide levels within 150 years, due to ïž
Increased coal usage ïž
And increased natural gas usage, ïž
although petroleum usage is likely to decrease due to increased cost and decreasing supply ïž