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Global Warming
and Climate Change
What is global warming?
A gradual increase in the
Earth’s temperatures as a result
of rising levels of carbon dioxide
and other greenhouse gases in
the atmosphere.
How Global Warming Works
Carbon Dioxide (CO2)
Fossil fuels (coal, oil, natural gas)
The Greenhouse
Effect
• Greenhouses can trap the
sun’s rays because of their
glass panels. This makes the
inside of them warm. This is
why in the winter they remain
warm enough to be able to
grow plants.
The Greenhouse
Effect
• When the sun’s rays pierce
onto the glass window of a
greenhouse, the rays become
weaker. Not all can pierce
back through into the air. This
causes the temperature
inside the greenhouse to rise
(get warmer).
The Greenhouse
Effect
• When the sun’s rays pierce
onto a window, they get
“trapped.” The rays cannot all
bounce back into the air. This
causes heating of the area,
which is known as the
greenhouse effect.
Example of the
Greenhouse Effect
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.
This Greenhouse Effect on
Earth
• A similar situation happens in the Earth’s atmosphere, but of course,
no window is involved.
• The greenhouse effect on Earth helps us understand temperatures of
the Earth, as well as the recent increase in the Earth’s temperatures,
known as Global Warming.
• The Earth’s greenhouse effect involves the sun’s rays, the Earth’s
atmosphere, and greenhouse gases which exist in the atmosphere.
• Let’s see...
The Greenhouse Effect on Earth
There are a tiny
number of gases (i.e.
carbon dioxide,
methane) found in
the Earth’s
atmosphere that
when they sun’s rays
are released, they
absorb some of the
heat before it can
escape back into
space. These are
called greenhouse
gases.
The Greenhouse Effect on Earth
Greenhouse gases
are essential for all
life on Earth. They
help keep some
heat (warmth) in the
Earth. Without
greenhouse gases,
temperature on
Earth would always
be about 30ºC
colder. It would be a
cold and lifeless
planet like Mars!
The Greenhouse Effect on Earth
We call them
“Greenhouse
Gases” because of
the way they warm
our Earth, very
similar to how a
greenhouse works
as we saw in
previous slides.
How does this contribute to Global
Warming?
Greenhouse gases have
been increasing due to
human activities that cause
pollution (i.e. the burning of
fossil fuels) in our
atmosphere. The increase
of greenhouse gases cause
the Earth to get HOTTER.
The atmosphere becomes
“thicker” and more heat
gets absorbed by
greenhouse gases, because
less can escape from the
thicker atmosphere. This
makes the Earth warmer.
This is called Global
Warming.
How does this contribute to Global
Warming?
Global Warming:
Warming of the
Earth’s
temperatures due to
a rise in greenhouse
gases in the
atmosphere.
Effects of Global Warming
•
•
•
•
•
Rise in sea levels
Chance in precipitation
Forests, farmlands
New parasites, new insect-borne diseases
Droughts, flooding
• http://www.youtube.com/watch?v=Z_jHP6xBLe
8
• http://youtu.be/n94lepehpm4
Assignment:
• Making Connections Textbook
– page 462 #1-3
What’s the difference
between “global warming”
and “climate change”?
Difference
GLOBAL WARMING
is the increase of the
Earth’s average
surface temperature
due to a build-up of
greenhouse gases in
the atmosphere.
CLIMATE CHANGE
is a broader term that
refers to long-term
changes in climate,
including average
temperature and
precipitation.
Effects of Global Warming
Rising Sea Level
Habitat Damage and
Species Affected
Increased Temperature
Changes in Water Supply
What’s the proof that
global warming is taking
place?
Portage Glacier
• Alaska
1914
Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org
2004
Colorado River
• Arizona
June 2002
Dec 2003
Why is global warming
happening?
Burning of Fossil Fuels
Pollution from coal,
natural gas, and oil
When did global
warming start?
Global Atmospheric Concentration of CO2
How is global warming
measured?
Ice Core Data
CO2 Measurements Before 1958 - Antarctica
CO2 Atmospheric
Measurements
CO2 Measurements Since 1958 – Mauna Loa, Hawaii
1000 Years of CO2 and
Global Warming
Temperature
(Northern Hemisphere)
2000
1800
Year
1600
1400
1200
1000
2000
1800
Year
1600
1400
1200
1000
Parts Per Million
Degree Celsius Increase
CO2 Concentrations
Global
Warming:
Shifting Gears
Billions of Metric Tons Carbon
Goal:
Reductions in
2007
CO2 Per Year
of Metric
Billions
Carbon Tons Carbon
Gigaton
Our Goal
2007
Reductions
in CO2
Per Year
Produce electricity
efficiently
Use electricity
efficiently
Vehicle efficiency
Solar and Wind
Power
Biofuels
Carbon capture an
storage
What’s being done now to
reduce our emissions?
Wind Power
Solar Power
Fuel-Efficiency
What can you do to help
solve the problem?
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.
Be Bulb Smart—Use CFLs
Incandescent
What’s the
difference?
500 lbs.
of coal
•1,430 lbs. CO2 pollution avoided
•$30 saved
Compact
Fluorescent
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.