Transcript global warming - Warren County Public Schools

8th Grade Science 10/28/2014
• Essential Question: How does
carbon dioxide emission affect
global warming?
• Objectives – I can…
• explain what the green house
effect is and how it causes global
warming
• Bell Ringer – Take out your bell
ringer paper for week 11. Copy
the prompt down and answer it in
a complete sentence.
• Write at least three questions
about the diagram/picture.
Agenda for today:
1. Complete presentations
2. 4th – 7th periods ONLY
1. Grade quizzes
3. Start notes on the
Greenhouse Effect and
Global Warming
The Greenhouse
Effect and Global
Warming
8th Grade Science
What is global
warming?
How Global Warming Works
Carbon Dioxide (CO2)
Fossil fuels (coal, oil, natural gas)
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.
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
Increased Temperature
Habitat Damage and
Species Affected
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
What is carbon dioxide and how is it
discovered?
Joseph Black, a Scottish chemist and physician, first
identified carbon dioxide in the 1750s. At room
temperatures (20-25 oC), carbon dioxide is an
odourless, colorless gas, which is faintly acidic and nonflammable. Carbon dioxide is a molecule with the
molecular formula CO2. The linear molecule consists of
a carbon atom that is doubly bonded to two oxygen
atoms, O=C=O.
Applications of carbon dioxide by humans
Humans use carbon dioxide in many different ways.
The most familiar example is its use in soft drinks and
rootbeer, to make them fizzy. Carbon dioxide
released by baking powder or yeast makes cake
batter rise. Some fire extinguishers use carbon
dioxide because it is denser than air. Carbon dioxide
can blanket a fire, because of its heaviness.
The part carbon dioxide plays in
environmental processes
• Carbon dioxide plays an important
part in vital plant and animal
process, such as photosynthesis and
respiration.
Environmental problems - the
greenhouse effect
• Greenhouse gasses absorb some of the heat
and trap it near the earth's surface, so that the
earth is warmed up.
• This process, commonly known as the
greenhouse effect.
• The amount of heat in the troposphere depends
on concentrations of atmospheric greenhouse
gasses and the amount of time these gasses
remain in the atmosphere.
• The most important greenhouse gasses are
carbon dioxide, CFC's (Chlor-Fluoro-Carbons),
nitrogen oxides and methane.
Carbon dioxide and health
The primary health dangers of carbon dioxide are:
- Asphyxiation. Caused by the release of carbon dioxide in a
confined or unventilated area. This can lower the concentration
of oxygen to a level that is immediately dangerous for human
health.
- Frostbite. Solid carbon dioxide is always below -78 oC at
regular atmospheric pressure, regardless of the air temperature.
Handling this material for more than a second or two without
proper protection can cause serious blisters, and other unwanted
effects. Carbon dioxide gas released from a steel cylinder, such
as a fire extinguisher, causes similar effects.
- Kidney damage or coma. This is caused by a disturbance in
chemical equilibrium of the carbonate buffer. When carbon
dioxide concentrations increase or decrease, causing the
equilibrium to be disturbed, a life threatening situation may occur.
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)
Year
Year
2000
1800
1600
1400
1200
1000
2000
1800
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
and storage
What’s being done now to
reduce our emissions?
Wind Power
Solar Power
Fuel-Efficiency
We can stop global
warming!
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?
Compact
Fluorescent
500 lbs. of
coal
•1,430 lbs. CO2 pollution avoided
•$30 saved
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.