2 Earth’s Heat Budget Changes in Earth’s heat budget can change climate The heat budget is a balance between reflection and absorption.IMPORTANT: Because 30% of the electromagnetic energy from the Sun has been reflected away, only 70% remains to interact with the Earth, and warm it up. 20% of the energy from the Sun is absorbed by the atmosphere as a whole heating it up. This leaves 50% of the Sun’s energy to heat both the surface of the Earth, as well as the oceans, lakes and streams.
3 Earth’s Heat Budget Reflection Atmosphere reflects 5% Clouds surface reflect 20%Earth’s surface reflects 5%= 30% TotalIf the reflection is increased, the temperature will decrease
4 Earth’s Heat Budget Absorption Atmosphere absorbs 20% Earth’s surface absorbs 50%= 70% TotalIf the absorption is increased the temperature will increase.Right now the temperature is increasing, one reason is due to an increase in atmospheric absorption (Greenhouse Gases)
5 How do we know climate is changing? EvidenceDirect (to understand present climates)ObservationsTemperaturePlant lifeIndirect (to predict past climates)Sea Floor SedimentsGlacier Samples (oxygen, distribution of shells)Tree Rings
9 Earth’s Motions Milutin Milankovitch The Shape of Earth’s Orbit ChangesThe Tilt and Axis of Rotation “Wobbles”These can affect seasons over long periods of time, changing the climateThis is possibly the reason for changes in ice cover during the last Ice Age
10 Plate Tectonics Greenland has Tropical Plant Fossils ~200 million years
11 Plate Tectonics Can change a specific area’s climate (Greenland) Can change global climateWind patternsOcean CurrentsIce sheetsContinents closer to poles = more ice =more reflection of sunlight = decrease in tempContinents farther from poles = less ice sheets =more absorption of sunlight = increase in tempDistributes heat differently
12 Volcanoes Mt Pinatubo (1991) Sent 20-30mega tons of sulfurous aerosols into the airAsh, dust, gases containing sulfur compoundsreflect sunlight into spaceWhat would happen to temperatures?
13 VolcanoesAfter the Mt Pinatubo eruption the global temperature fell ~0.5°C or 0.9°F the next yearThe ash and sulfuric compounds actually reflected sunlight back into spaceBUT . . .What else do volcanoes release?Carbon DioxideAnd What is Carbon Dioxide?
14 Volcanoes Carbon Dioxide is a Volcanoes can cause greenhouse gas Greenhouse gases cause temperatures to increaseVolcanoes can causeShort term cooling (aerosols and sulfuric compounds)Long term warming (carbon dioxide)greenhouse gas
15 SunspotsThere is an 11 year sunspot cycle that changes how much radiation is given off by the sun.More sunspots = More energy
16 What Is Earth’s Heat Budget? The balance between its reflection and absorption of sunlightThe balance between its temperature and air pressureHow much money it can spend monthly
17 Why Is The Earth’s Heat Budget Important? It is the reason why we have volcanic eruptionsIt causes sunspotsChanges in it can cause changes in global climateIt is a contributor to plate tectonics
18 What is the average percentage of reflection? Absorption? 20% and 80%20% and 90%30% and 70%60% and 40%70% and 30%
19 What Are Examples Of Signs That Climate Is Changing? ObservationsTemperaturePlant LifeTree RingsGlacier SedimentsSea Floor SedimentsAll Of The Above
20 What Factors Cause Climate Change? Earth’s MotionsPlate TectonicsSunspotsVolcanoesHuman ActivitiesAll Of The Above
21 Milutin Milankovitch Said… Humans are the reason for global climate changesThe “wobble” of the Earth’s rotation alters seasons and climatesThe Earth is absorbing less energy from the sun
22 Large Volcanic Eruptions Can Cause… Short term cooling and long term warmingShort term warming and long term coolingNo effects to the atmosphere
23 T/F: The 11 Year Cycle Of Sunspots Changes How Much Energy The Earth Receives TrueFalse
25 It is evident that climate has been changing without humans but do we have an impact on climate change?
26 Fossil Fuels Fossil fuel use is one way humans impact the planet. Climate is affected because CO2 and other gases are emitted into the atmosphere.
27 Fossil Fuels Fossil fuels The sun’s energy trapped within Earth’s crustThe hydrocarbons were stored mainly in plants (photosynthesis)Can be coal, natural gas, and oil (petroleum).Used for MANY things… not just power.
29 Consequences of Fossil Fuel Use Caused by Impacts Temperature IncreaseIncreased greenhouse gases in atmosphereBreak down of ocean currents, changes in climate patterns, loss of agricultural spacePollutionIncreased emission use will increase pollutantsAir quality, health risks, species lossSea Level RiseWater expansion, melting of land ice (glaciers)Loss of coastal space, species loss, changes in migration
30 Who Are The Worst Offenders Of CO2 Emissions and Energy Use? African CountriesIndiaChinaUSAEuropeBrazilAustraliaMiddle East
31 CO2 Emissions (Per Person) SOURCE: http://en. wikipedia
38 NASA photographs show the minimum Arctic sea ice concentration in 1979 at left and in 2003.Satellite passive microwave data since 1970s indicate a 3% decrease per decade in arctic sea ice extent.
39 Source:Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (
40 If all of the ice caps melted then sea level would raise by 65 m Kennedy SpaceCenterImpact of a 1 mrise in sea levelon low-lying areasIf all of the ice caps melted then sea level would raise by 65 mAreas subjected toInundation with a 1 m(~3 ft) rise in sealevelMiamiSource:Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (
41 To sum it up. . . Climate has changed a lot over Earth’s history There are many factors to climate changeSome we have no control over and some we do have control overWill Earth survive if the climate changes A LOT?Yes, but will we?
42 Humans Are The Only Reason For Global Warming Strongly AgreeAgreeDisagreeStrongly Disagree
43 T/F: Our Reliance On Fossil Fuels Will Continue Into The Foreseeable Future… TrueFalse