88THTH GRADE SCIENCE GRADE SCIENCE

STRAND 4STRAND 4

EARTH AND SPACE SCIENCEEARTH AND SPACE SCIENCE

ESS.8.8.1ESS.8.8.1

VOCABULARYVOCABULARY

• 1. GLOBAL WARMING – GLOBAL TEMPERATURES RISE DUE TO AN INCREASED GREENHOUSE EFFECT.• 2. GREENHOUSE EFFECT – NATURAL HEATING CAUSED BY ATMOSPHERIC GASES TRAPPING HEAT

AT EARTH’S SURFACE.• 3. DEFORESTATION – THE REMOVAL OF FORESTS,

MOSTLY TO CLEAR LAND FOR FARMING, CONSTRUCTION, MINING, AND DRILLING FOR OIL.

• 4. REFORESTATION – THE PLANTING OF A LARGE NUMBER OF TREES.

• 5. ozone layer – layer in our atmosphere that protects living things by absorbing harmful

ultraviolet radiation from the sun.

vocabularyvocabulary

• 6. Chlorofluorocarbons – a group of chemicals used as refrigerants and

aerosol spray propellants that destroy ozone molecules.

• 7. carbon dioxide (co2) – a gas consisting of carbon and oxygen

which vegetation helps to remove it from air.

• 8. ultraviolet radiation (uv rays) – harmful rays from the sun, which cause sunburn, skin cancer, etc.

GLOBAL WARMINGGLOBAL WARMING

• GLOBAL WARMING MEANS GLOBAL TEMPERATURES ARE RISING.

• ONE REASON FOR GLOBAL WARMING IS THE INCREASE OF GREENHOUSE

GASES IN OUR ATMOSPHERE.• THIS INCREASES THE “GREENHOUSE

EFFECT”• IN THE LAST 100 YEARS, THE MEAN

TEMPERATURE ON EARTH HAS INCREASED 1/2½ DEGREE CELSIUS.

GLOBAL WARMINGGLOBAL WARMING

• JUST RECENTLY, SCIENTISTS HAVE REPORTED THAT THE EARTH IS THE

WARMEST IT HAS BEEN IN 400 YEARS.• IF THE MEAN TEMPERATURE

CONTINUES TO RISE, ICE CAPS WILL MELT. LOW LYING AREAS MIGHT

EXPERIENCE INCREASED FLOODING.• ALREADY SOME ICE CAPS ARE

BEGINNING TO BREAK APART, AND SEA LEVEL IS RISING IN SOME AREAS.

CLASSWORKCLASSWORK

• Now, take out a sheet of paper. On it, tell me what effect global

warming will have on you.• Be creative!

• You will have about 4 minutes.

GLOBAL WARMINGGLOBAL WARMING

• HUMAN ACTIVITIES AFFECT THE AIR IN OUR ATMOSPHERE. BURNING FOSSIL FUELS AND REMOVING VEGETATION

AFFECT THE ATMOSPHERE. BOTH ACTIVITIES ADD CARBON DIOXIDE TO THE

ATMOSPHERE AND CONTRIBUTE TO GLOBAL WARMING.

• BY ANALYZING AIR BUBBLES TRAPPED IN GLACIERS, SCIENTISTS HAVE DISCOVERED

THAT IN ABOUT 1750, THERE WERE 280 PARTS PER MILLION OF CARBON DIOXIDE IN THE ATMOSPHERE. TODAY THERE ARE

MORE THAN 350 PARTS PER MILLION.

GLOBAL WARMINGGLOBAL WARMING

• WHEN NATURAL GAS, PETROLEUM, AND COAL ARE BURNED FOR

ENERGY, THE CARBON IN THESE FOSSIL FUELS IS COMBINED WITH

OXYGEN. THIS INCREASES THE AMOUNT OF CARBON DIOXIDE (CO2)

IN THE ATMOSPHERE.• THE MASS REMOVAL OF TREES, CALLED “DEFORESTATION” ALSO

AFFECTS THE AMOUNT OF CARBON DIOXIDE IN THE ATMOSPHERE.

GLOBAL WARMINGGLOBAL WARMING

• FORESTS AROUND THE WORLD ARE BEING CLEARED FOR MINING, ROADS,

BUILDINGS, GRAZING CATTLE, AND DRILLING FOR OIL.. FORESTS ARE

ALSO DYING FROM THE EFFECTS OF POLLUTION.

• AS TREES GROW, THEY TAKE IN CARBON DIOXIDE. WHEN TREES ARE

REMOVED, THE CARBON DIOXIDE THEY COULD HAVE REMOVED FROM

THE ATMOSPHERE IS LEFT.

GLOBAL WARMINGGLOBAL WARMING

• OUR WEATHER CAN ALSO BE AFFECTED BY GLOBAL WARMING.

• HURRICANES WILL CONTINUE TO GET STRONGER. They get their

energy from the warm water they form in.

• If the water is getting warmer due to global warming, hurricanes will

have the extra energy to get bigger and stronger.

Global warmingGlobal warming

• Weather on the inland could also be affected.

• Our severe weather is caused when hot air and cold air run into each other.

• Cold air and warm air have different densities and do not mix, they battle

each other.• Increasing the temperature of the air

would increase the severity of the storms.

Global warmingGlobal warming

• Also adding warmth to the increasing global temperature is the

deterioration of our ozone layer.• The ozone layer helps absorb harmful

ultraviolet rays from the sun.• Chlorofluorocarbons (cfc’s) that we use in air conditioners, refrigerators, aerosol sprays, etc. break apart the ozone molecules in the ozone layer.• A huge hole in our ozone layer continues to grow because of this.

reviewreview

• 1. these are in aerosol sprays, air conditioners, and refrigerators that break

apart ozone molecules……• Chlorofluorocarbons

• 2. this is a gas in our atmosphere made up of carbon and oxygen……

• Carbon dioxide• 3. this is the rising average temperature of

the earth…• Global warming

• 4. the sun’s rays come in, but have a hard time getting back out because of the amount

of carbon dioxide in the air….• Greenhouse effect

reviewreview

• 5. what does vegetation do for our air?• It uses the carbon dioxide in the air.• 6. the mass cutting of our trees for

commercial purposes……• Deforestation

• 7. the harmful rays from the sun which cause sunburn and skin cancer…..

• Ultraviolet radiation.• 8. The mass replanting of trees on our

planet is called……• Reforestation.