• 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 HISTORY OF EARTH’S CLIMATE
ATMOSPHERE•Atmosphere is an insulating blanket protecting the earth.•It protects the earth from many harmful rays, emitted by the sun.•The infrared rays from the sun are falling on the earth’s surface•Some are reflected back and some rays will remain in the surface and some are trapped inside the atmosphere•The trapped rays will maintain the temperature of the earth.
Global warming is the warming of the earth through carbon dioxide being pumped into the atmosphere from tailpipes and smokestacks.Then the gases trap heat like the glass in a greenhouse. This is where the term the “greenhouse effect” came from.
How Global Warming Works Carbon Dioxide (CO2) Fossil fuels (coal, oil, natural gas)
• Carbon dioxide emissions from fossil fuel burning power plants.• When fossil fuels are burned they give off a green house gas called CO2.
• Another major man-made cause of Global Warming is population.• More people means more food, and more methods of transportation.• That means more methane because there will be more burning of fossil fuels, and more agriculture.
Carbon dioxide emissions from burning gasoline for transportation.
Deforestation-Especially tropical forest for wood, pulp and farm land
Increase in usage of chemical fertilizers on croplands
Rise in sea levels Scientists predict an increase in sea levelsworldwide due to the melting of two massive ice sheets in Antarctica and Greenland, especially on the East coast of the U.S.
More killer stormsScientists have come up with thefirmest evidence so far that globalwarming will significantly increase theintensity of the most extreme stormsworldwide.The maximum wind speeds of thestrongest tropical cyclones haveincreased significantly since1981, according to research published inNature this week.
Massive crop failures• Climate change is expected to have the most severe impact on water supplies.• “Shortages in future are likely to threaten food production, reduce sanitation, hinder economic development and damage ecosystems.• It causes more violent swings between floods and droughts.”“
Widespread extinction of species• Climate change now represents at least as great a threat to the number of species surviving on Earth as habitat- destruction and modification.”
Disappearance of coral reefs• For reefs, warming waters and acidification are closing in like a pair of jaws that threaten to make them the first global ecosystem to disappear.”
What’s the differencebetween “global warming” and “climate change”?
DifferenceGLOBAL WARMING CLIMATE CHANGE is the increase of the is a broader term that Earth’s average refers to long-term surface temperature changes in climate, due to a build-up of including average greenhouse gases in temperature and the atmosphere. precipitation.
What’s the proof thatglobal warming is taking place?
Where Has It Been Happening This is where temperatures have risen in the world.
The yellow represents warming, melting glaciers, flooding and rising ofsea level. The red represents the spread of disease, earliersprings, plant and animal shifts and population changes, coral reefbleaching, downpours, heavy snowfalls, and flooding, droughts andfires.
What’s being done now to reduce our emissions?
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 What’s the CompactIncandescent difference? 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 turningup the heat. Offer to help your parents keep the air filters on your AC and furnace clean.Walk short distances instead of asking for aride in the car. Plant a tree. Recycle.