about global warming

2. 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

3. 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

4. What is global warming?

5. The sun sends out energy
as heat and light. This
energy comes to our
earth during the day time.
Some of the sun’s rays get
‘trapped’ in the
atmosphere.
Some of them get reflected
back into space.
The ones which get through
the atmosphere warm the
earth up.

6. All the time, the
earth radiates heat
into space, which
cools it down. We
only really notice this
at night, when there
is no heating from
the sun.
Some of the heat going out is
trapped by the
atmosphere(carbon dioxide).
This is what makes our planet
warm enough to live on.
But if too much heat is
trapped, our planet will warm
up and the climate will
change.

7. Sun
Earth’s Temperature
Solar
Energy
Solar
Energy

8. Sun
Earth’s Temperature
Solar
Energy
Radiation
Cooling

9. Sun
Earth’s Temperature
Solar
Energy
Radiation
Cooling

10. How Global Warming Works
Carbon Dioxide (CO2)
Fossil fuels (coal, oil, natural gas)

11. What is the atmosphere and
why does it trap heat?
The atmosphere is the air around
the surface of the earth. It is made
from a mixture of gases. We need
it for animals and plants to survive.
Some of the gases act like a
blanket, trapping heat. These
gases are called ‘greenhouse
gases’.
This is known as the ‘Natural
Greenhouse Effect’. Without it, the
earth would be much colder.
(the atmosphere is
really much thinner
than it looks
above)

12. 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

13. Why is global warming
happening?

14. Burning of Fossil Fuels
Pollution from coal,
natural gas, and oil

15. • HUMAN ACTIVITIES
• VOLCANIC ERUPTIONS
• DEFORESTATION

16. DEPLETION OF OZONE
LAYER

17. EFFECTS OF GLOBAL WARMING

18. • INCREASE IN TEMPERATURE
• RISE IN SEA LEVEL
• STORMS

19. What’s the proof that global
warming is taking place?

20. Portage Glacier
1914 2004
• Alaska
Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org

21. Colorado River
• Arizona
June 2002 Dec 2003

22. How is global warming
measured?

23. Ice Core Data
CO2 Measurements Before 1958 - Antarctica

24. Blowing Up Your World
• 1. How many of you leave your
bedroom light on when you
are not in the room?
• Turning off lights saves energy and
money. 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. Blowing Up Your World
• How many of you, when you drink a
soft drink, throw the container into the
garbage?
• Throwing away containers of any kind wastes
energy and resources and adds to our waste
problem. Many towns are running out of landfill
space. 3 pts d

26. Blowing Up Your World
• How many of you use a hairdryer or
other energy-consuming convenience
appliance, especially in the morning?
• Hairdryers use a lot of energy. In the
morning so much energy demand is
put on our grids that power companies
have to find other sources of energy just
to meet the morning rush hour 2 pts d

27. Blowing Up Your World
• . How many of you, when you go to a
store, get a bag for your purchases,
even if you have only one or two small
items to carry?
• Making paper and plastic bags uses
energy and resources. The bags add to
our litter and waste problems, and
plastic is not biodegradable. Recycling
is not the best answer because
collecting and recycling materials
requires energy. Instead, carry a
reusable cloth bag or a knapsack with
you. 3 pts d

28. Blowing Up Your World
• How many of you eat take-out or cafeteria
food that is served in foam or plastic
containers?
• Polystyrene and other plastic containers are
made from precious petrochemicals, do not
decompose in landfills, and release toxic
gases when they are burned in incinerators.
10 pts d

29. Blowing Up Your World
• How many of you use handkerchiefs
instead of tissues and use cloth towels
instead of paper towels?
• Paper comes from trees. The more of it
we use, the more trees that are cut
down 2 pts d

30. So how can each of us slow
global warming now?

31. 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.
(

32. What’s being done now to
reduce our emissions?
Wind Power Solar Power Fuel-Efficiency

33. What can you do to help
solve the problem?

34. Simple Things To Do
Turn off your computer or the TV
when you’re not using it.
Take shorter showers. Heating water uses energy.
Keep rooms cool by closing the blinds, shades, or
curtains.
Turn off the lights when you leave a room.
Use compact fluorescent bulbs.

35. Simple Things To Do
Dress lightly when it’s hot instead of turning
up
the air conditioning. Or use a fan.
Dress warmly when it’s cold instead of turning
up the heat.
Offer to help your parents keep the air filters on
your AC and furnace clean.
Walk short distances instead of asking for a
ride in the car.
Plant a tree. Recycle.

36. Be Bulb Smart—Use CFLs
Incandescent
Compact
Fluorescent
What’s the
difference?
500 lbs. of
coal
•1,430 lbs. CO2 pollution avoided
•$30 saved

37. We humans are thought to be
the main cause of global
warming and climate
change……..
but we still have the chance to
do something about it.

38. Our take-home message…
Each of us must take steps to protect
our Earth's climate.

40. PRESENTATION BY..........
UJWAL
137Z1AO117
GAUTHAM
137Z1AO128
CIVIL 1ST YEAR