In examining global warming, we will be looking at questions such as Is the world getting warmer? If so, are the actions of mankind to blame for earth’s temperature increases? What can or should be done about global warming? Are the potential resolutions to global warming worth the cost to implement them?
This is a big picture examination of the earth’s climate The Earth was formed around 4.6 billion years ago And was originally very hot However, the Sun’s energy output was only 70% of what it is presently Liquid water was present on the surface around 4.3 billion years ago
The first life forms appeared ~3.8 billion years ago Photosynthesis began 3.5-2.5 billion years ago, which produced oxygen and removed carbon dioxide and methane, which are greenhouse gases, from the atmosphere As a result, the Earth went through periods of cooling, commonly referred to as “Snowball Earth” and subsequent warming Earth began its current cycles of glacial and interglacial periods around 3 million years ago
The temperature of the earth is directly related to the energy input from the Sun. Some of the Sun’s energy is reflected by clouds. Other is reflected by ice. The remainder is absorbed by the earth.
If amount of solar energy absorbed by the earth is equal to the amount radiated back into space, the earth remains at a constant temperature.
However, if the amount of solar energy is greater than the amount radiated, then the earth heats up.
If the amount of solar energy is less than the amount radiated, then the earth cools down.
To a certain degree, the earth acts like a greenhouse. Energy from the Sun penetrates the glass of a greenhouse and warms the air and objects within the greenhouse. The same glass slows the heat from escaping, resulting in much higher temperatures within the greenhouse than outside it.
Likewise, the earth’s atmospheric gases affect the ability of the earth to radiate the Sun’s energy back into space. Nitrogen and Oxygen make up 99% of the earth’s atmospheric gases and are non-greenhouse gases. Water, Carbon Dioxide, and Methane make up 1% of the earth’s atmosphere, but are greenhouse gases, since they cause the earth to retain heat.
This spike is due to the exponential increase in the use of fossil fuels over the last 150 years. Shown here are emissions of carbon from gas, solid, liquid fuels, and the total carbon emissions.
Despite this rapid increase in carbon emissions, only about half the carbon can be detected in the atmosphere. The remainder of the carbon dioxide is being dissolved in the oceans or incorporated into trees.
Future Carbon Emissions will probably increase, especially in China and developing countries This will result in a likely doubling of carbon dioxide levels within 150 years, due to Increased coal usage And increased natural gas usage, although petroleum usage is likely to decrease due to increased cost and decreasing supply
Making a DifferenceOne Watt at a Time
Introduction• Is the world getting warmer?• If so, are the actions of mankind toblame for earth’s temperatureincreases?• What can/should be done about theseissues?
History of Earth’s Climate• Earth formed ~4.6 billion years ago• Originally very hot• Sun’s energy output only 70% ofpresent• Liquid water present ~4.3 billion years
History of Earth’s Climate• Life appeared ~3.8 billion years ago• Photosynthesis began 3.5-2.5 billion yearsago– Produced oxygen and removed carbondioxide and methane (greenhouse gases)– Earth went through periods of cooling(“Snowball Earth”) and warming• Earth began cycles of glacial andinterglacial periods ~3 million years ago
The U.S. emits about 6.4 billion metrictons of greenhouse gases annually, 25%of the world’s total.Carbon dioxide stays in theatmosphere for approximately100 years, methane lasts about12 years. Other greenhousegases last even longer.As these gases continue to raise surfacetemperatures, they trigger the release of evengreater quantities of carbon dioxide and methanethat are currently trapped in frozen Arcticpermafrost and tundra soils, further increasingtemperatures.…potentially causing “runaway global warming”.6.4 billion metric tonsCO2/yrThese greenhouse gases last along time…Warming begets more warming…A feedback mechanism ensues…
Future Carbon DioxideLevels• Increasing CO2 emissions, especiallyin China and developing countries• Likely to double within 150 years:– Increased coal usage– Increased natural gas usage– Decreased petroleum usage (increasedcost and decreasing supply)
Of all U.S. greenhouse gasemissions come fromhouseholds:• Vehicles• Home Heating• ElectricityHouseholds are Big Contributors to Climate Change
Because greenhouse gas emissions are tied very closely to ourenergy consumption, using less fossil fuel based energy puts fewergreenhouse gases into the atmosphere.This will help slow global warming.Reduce our consumption of fossil fuelsMountaintop removal forcoal mining near Rawl,West Virginia.50% of electricity in theUnited States is producedfrom coal.(
How much energy are those bulbs using?1 2 3 4 5 6 7Wattageof the bulbs# ofbulbsWattsUsed(Wattagex numberof bulbs)Hours usedper dayWatts Used(#3) x TotalHours/day(#4)Wattshours /year(#5 x 365days)Kilowatthours /year(1000Wh =1kWh)(divide #6by 1000)(Incandescentbulbs)60 W3bulbs(60 x 3)180 W10 hours aday(180 x 10)1800Wh/day(1800 x 365)640,800Wh/ year(640,800/1000)640.8kWh peryear(CFL bulbs)18 W 3bulbs18 x354 W10 hours aday54 x 10540Wh/day540x365197,100Wh/day197,1001000197.1kWh/yr
IncandescentsCompact Fluorescents(CFLs)Total kWh for 3 bulb (#7 fromabove)640.8 kWhCost (kWh #7 x $.18)CO2 produced @ 1.16 lbs/kWh lbs lbsCO2 not emitted by switching 3 bulbs(C O2 of incandescents - C O2 of CFLs)lbsMoney saved in energy(Cost incandescents - cost of CFLs)3 BULB REPLACEMENT EMISSION and COST COMPARISONINCANDESCENT vs. COMPACT FLUORESCENT197 kWh$115.34 $35.46743.3 228.52514.8$79.88
We can make some simple substitutionsReplacing just 1 incandescent light bulb with 1 compactflorescent bulb saves about 150 pounds of carbondioxide per year!If every American household replaced just 5 high-useincandescent bulbs with compact florescent lights wedcollectively save more than $8 billion each year in energy costsand we would prevent the greenhouse gases equivalent to theemissions from nearly 10 million cars.Source: http://www.energystar.gov
Small changes really add upReplace your old refrigeratorwith a new Energy Star:Annual savings:$90; 700 pounds CO2Set your thermostat down a fewdegrees in the winterAnnual savings:$135; 1400 pounds CO2Wash clothes in cold water onlyAnnual savings:$70; 500 pounds CO2Drive JUST 10 fewer miles per weekAnnual savings:$80; 520 pounds CO2Reduce your garbage by 10%through greater recycling or reducedpackagingAnnual savings:1200 pounds CO2Caulk and weather-strip around doorsand windowsAnnual savings:$80; 650 pounds CO2*These are mid-range estimates frompublished sources; your savings may vary.
Blowing Up Your World• 1. How many of you leave yourbedroom light on when you arenot in the room?• Turning off lights saves energy andmoney. The more energy used, themore rivers are dammed or more fossilfuel is burned, causing air pollutionand increased levels of carbon dioxidein the atmosphere. 2 pts d
Blowing Up Your World• How many of you walked, bicycled ortook public transportation to get toschool today, instead of coming byprivate automobile?Our reliance on cars that burn fossil fuelsis one of the major causes of increasedlevels of carbon dioxide in the atmosphereand it is the primary cause of urban smog.3 pts u
Blowing Up Your World• How many of you, when you drink asoft drink, throw the container into thegarbage?• Throwing away containers of any kind wastesenergy and resources and adds to our wasteproblem. Many towns are running out of landfillspace. 3 pts d
Blowing Up Your WorldHow many of you eat fresh vegetablesinstead of canned or frozen?Fresh vegetables cook more quickly and areusually more nutritious than frozen or cannedfoods. Canned and frozen vegetables are oftenover-processed, contain additives, contribute toair pollution (transport and packaging) and addto our waste problem. 4 pts uBlowing Up Your World
Blowing Up Your World• How many of you use a hairdryer orother energy-consuming convenienceappliance, especially in the morning?• Hairdryers use a lot of energy. In themorning so much energy demand is puton our grids that power companies haveto find other sources of energy just tomeet the morning rush hour 2 pts d
Blowing Up Your World• . How many of you, when you go to a store,get a bag for your purchases, even if youhave only one or two small items to carry?• Making paper and plastic bags uses energyand resources. The bags add to our litterand waste problems, and plastic is notbiodegradable. Recycling is not the bestanswer because collecting and recyclingmaterials requires energy. Instead, carry areusable cloth bag or a knapsack with you.3 pts d
Blowing Up Your WorldHow many of you carry your lunch toschool in a lunch box or reusablecontainer?Making paper and plastic bags usesenergy and resources. 3 pts u
Blowing Up Your World• How many of you eat take-out or cafeteriafood that is served in foam or plasticcontainers?• Polystyrene and other plastic containersare made from precious petrochemicals,do not decompose in landfills, andrelease toxic gases when they areburned in incinerators.10 pts d
Blowing Up Your World• How many of you use handkerchiefsinstead of tissues and use clothtowels instead of paper towels?• Paper comes from trees. The more ofit we use, the more trees that are cutdown 2 pts d
Blowing Up Your World• How many are changingincandescent bulbs for new compactfluorescent bulbs?Changing one bulb could save 150pounds of carbon dioxide per year!10 pts u
Blowing Up Your World• 31 - 40 Very good. Youre anenvironmentalist!• 21 - 30 Good, youre starting to savethe world.• 11 - 20 Lots of room for improvement.• 0 - 10 Youre exiled to the town dump!
Our take-home message…Each of us must take steps to protectour Earths climate.