climate change and greenhouse effect notes. what we want to know? what is climate change? what is...
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Climate ChangeandGreenhouse Effect Notes
What we want to know?What is climate change?What is the greenhouse effect?How will climate change affect the earth?How will it affect me?What can I do about it?Any other questions?
Basics of Manmade Climate ChangeEarth has existed for 4.5 billion years.Earths climate has changed due to natural cycles in the past.Many times, these cycles push the Earth to extreme environments and climates.However, human activities have introduced new impacts to our environments we cant ignore.These human activities are increasing greenhouse gases that enhance and have an impact on Earths climate.If nothing is done, these changes will reach a tipping point of no return.
What is the Earths Atmosphere made of?
Where is the atmosphere most dense?The atmosphere is most dense at the Earths surface.
The atmosphere gets less dense the farther you are from the earths surface.
Why doesnt the atmosphere float away?The earths gravity holds onto it (just like you!)
The Earths AtmosphereTroposphereThe lowest layer of the atmosphere (the troposphere) contains 90% of the atmospheres mass and is where the weather occurs.
The Earths AtmosphereStratosphereStratosphere contains the ozone layer (03)03 absorbs UV radiationOzone is bad for us to breathe but good in the stratosphere
Solar RadiationAnd why its important
What is solar radiation?Solar radiation is energy from the sun
What is solar radiation?Energy from the sunElectromagnetic waves (type of energy that can move through space)Comes in different wavelengths Generally, the shorter the wavelength the more intense (higher energy) the radiation
Why is solar radiation important?Is the basis of nearly all food chainsKeeps our earth warmDrives all wind and weatherImportant to understand climate change
Wavelength SizesSolar Radiation
The three types of solar radiation are:1. Ultra-violet (UV), which is short wavelengths and harmful. The ozone layer protects us from UV rays.
The three types of solar radiation are:2. Visible light (what humans see). Wavelengths are longer
Three types of solar radiation are:3. Infrared radiation (what we feel as heat). These are really, really long wavelengths and important to understand for greenhouse effect. These are what greenhouse gases ABSORB.
What happens when solar radiation strikes Earth?1. 50% of solar radiation is absorbed by the earths surface (as heat energy)2. 20% absorbed by atmosphere30% reflected back into outer spaceWere interested in the heat absorption part of our atmosphere.
Then what happens? This absorbed heat energy is eventually transferred back to the atmosphere through infrared radiation. These were the really long wavelengths.
Greenhouse gases, such as CO2,CH4 ,N2O, H2O and O3 are good absorbers of infrared radiation thats why these are considered greenhouse gases! When they absorb infrared radiation, the atmosphere becomes warmer this is the greenhouse effect!
Similar to a car on a hot day.Light energy easily passes through the windshield, but the longer wavelength infrared radiation that is re-transmitted by the cars interior cant escape through the glass very well thus the car heats up!The car behaves like the EarthThe windshield acts like the atmosphere
What is a Greenhouse?
A greenhouse is a little house made of glassor plastic windows.
What is a greenhouse? (contd) Sunlight comes in warming the air inside the greenhouse. Heat cant escape because of the windows. A greenhouse is warmer than the air outside. People can grow plants in greenhouses in the winter because its warm inside the greenhouse.
The Greenhouse Effect on Earth Earths atmosphere acts like a greenhouse. It lets sunlight in and the sunlight warms the air. The atmosphere traps the warm air like a greenhouse!
The Greenhouse Effect on the Earth
What are greenhouse gases? These are the gases in the atmosphere that absorb infrared radiation and hold in the heat and make the greenhouse effect happen.
What are the greenhouse gases?These gases are:CO2Carbon dioxideCH4 MethaneN2ONitrous OxideH2OWater
Distribution of Greenhouse Gases in Earths Atmosphere
Whats the big deal with Greenhouse Effect? We NEED the greenhouse effect to live!!! Without the greenhouse effect, the whole earth would be below freezing every night! The plants would freeze and die. There would be no oxygen. We would all DIE!
The Greenhouse Effect The greenhouse effect is similar to a car on a hot day. The most common greenhouse gas is CO2 (carbon dioxide). It absorbs infrared heat REALLY well.
Humans increase CO2 in the atmosphere by burning fossil fuels (such as gasoline, natural gas, and coal) and by burning forests is increasing greenhouse effect to create climate change (not good).
Whats your carbon footprint?
Greenhouse Effect Our animals also contribute methane to the atmosphere. Example: Cow farts, Cow poop, and decomposing things
ClimateChangeThe realities and myths
Scientists agree thatSome parts of the earth are warming and other parts cooling.The warming is caused primarily by increasing greenhouse gases.Warming will continue unless greenhouse gas emissions through human activities are reduced.
Scientists disagree aboutThe rate of warmingThe impact of climate change on ecosystems, human health, etc.
EvidenceDirect temperature and greenhouse gas observations over the past 150 yearsTemperature & CO2 data from ice core samples over the past 400,000 years
EvidenceGlacier Dataglaciers in European Alps have shrunk 30-40%glaciers in New Zealand have shrunk 25%glaciers on Mt. Kilimanjaro (Kenya) have shrunk 60%All glaciers PNW are also shrinking
Of course, this is something that could NEVER be proved because.Could never observe it all directly always have to rely on some inferenceCant perform a controlled experiment with the earth
Possible Impacts:Melting ice (glaciers, etc.)Decreased snow packs (leading to drought)Rising sea levels Coastal floodingChanges in ocean salinity (saltiness)
Possible Impacts:Changes in ocean currentsIncreased temperature & heat wavesDecreased temperature and dramatic coolingChanges in precipitation (less in some areas, more in others)More extreme weather events (storms, hurricanes, etc.)
Possible Impacts:Decreased crop/food productionExtinction of many species gone forever!