chem of le atmospheré Flashcards
how we know what atmo was like b4
Scientists know the historic composition of the air by analysing the tiny air bubbles trapped
in ice cores taken at the poles
The air bubbles were trapped as the snow and ice was laid down tens of thousands of years
ago and provide a snapshot of what our atmospherewas likeback then
1 thery on hw erly amto form
Onetheoryofhow theearly atmosphereformedsuggests thatthevolcanoes released
gases from theEarth’s interiorthrough violenteruptions
released lotsof co2, h2o, n2, h2
Earth’s gravitypreventedthegases from escapingintoouter spaceandthey formedthe
early atmosphere
surface of early earth
Thesurfaceoftheearly Earth was molten formillions of years duringwhich timetherewas
noatmospheresurroundingtheplanet
how land masses formed?
Eventually, coolingbegan totake effect andallow formolten materials toslowly solidify
forminglandmasses
rising sea lvl
Themeltingofthepolaricecaps andglaciers is leadingtorisingsea levels
This results in destructiveerosion tocoastalregions, floodingofwetlands andhabitat
destruction forbirds, fish andplants
Low lyingcities arelikely toseeincreasedfloodingandpermanentloss ofusableland
withoutexpensivebarrier systems
Increasedsoil salinity is alsoa consequenceofrisingsea levels
early amtosphere levels
lots of co2
very little o2
some water vapoiur
some n2
other gases
uv ray hitting earth
When shortwavelength radiation (e.g.ultravioletradiation)from thesun strikes theEarth’s
surface, itis absorbedandre-emitted from thesurfaceoftheEarth as infraredradiation
which has a longerwavelength
how ocean form
WhilethesurfaceoftheEarth was still very hotthelargequantities ofwater vapour
remainedin thegaseous state
When conditions cooled suffciently,thewater vapourlatercondensed andfelltothe
surfaceoftheEarth,formingtheoceans
methods to estimate past climate conditions
Therearesomemethods toestimatepastclimateconditions,which include:
Analysis ofthefossilrecord andtreerings
Analysis ofgas bubbles trappedin icefrom hundreds ofthousands of years ago
how sedimentry rock form
Animals fedon theplants which transferredcarbon totheirtissues includingbones and
shells
When theseorganisms died,theirremains formedsedimentary rocks
how ocean forming reduce co2 in atmo
Carbon dioxideis a water solublegas (itis thegas usedin fizzydrinks) anddissolves readily
When thewater vapourcondensed largeamounts ofCO dissolvedin theoceans
Carbonatesubstances wereprecipitated duringthis process which laterformed
sediments
Theseprocesses reducedtheamountofcarbon dioxidein theatmosphere
greenhouse effect
Greenhousegases maintain thetemperatures on Earth which is known as thegreenhouse
effect
hat contribute to methane inc in air
morewastesomorelandfill sites areneededwhich increases theamountof
methanebydecomposition
enhanced greenhouse effect
Increasinglevels ofcarbon dioxideandmethane, although presentin only small amounts,
arecausingsignificant upsettotheEarth’s naturalconditions by trappingextra heatenergy
how co2 locked up
Someofthelivingorganisms wereburiedunderlayers ofmudwhen theydied
Overmillions of years,theheat andpressureturnedthedeadorganisms intofossil fuels,
such as crudeoil, naturalgas andcoal
Theformation of sedimentary rock andfossilfuels ‘lockedup’thecarbon from carbon
dioxidein theearly atmosphere
how o2 level inc
plants andalgaebegan photosynthesisingwhich usedupcarbon dioxidefrom
theatmosphereandreleasedoxygen:
uv being stored on earth
Much oftheradiation, however, is trapped insidetheEarth’s atmospherebygreenhouse
gases which can absorbandstoretheenergy
deforestation
increase global warming
burning tree release co2
also less tree to take in co2
storms
Theintensityof storms is increasing
Warmerocean surfaces mean moremoistureis enteringtheatmospheresostorms and
hurricanes aremoreenergetic anddestructive
droughts
Someregions areseeingdevastatingdroughts leadingtocropfailureandcollapseof
agriculturalproduction
Foodproduction is greatly compromisedleadingtohardshipandstarvation
extreme heatwaves and rainfall
Extremeweatherevents arebecomingmorefrequentresultingin greatloss oflifeand
destruction ofinfrastructureandecosystems
Changingrainfallpatterns areleadingtouneven distribution offreshwater supplies
Lackofreliablefreshwater supplies results in economic andpolitical instability as
neighbouringcountries competefordwindlingresources
fuel - hydrocarbons
Afuel is a substancewhich releases energy in an exothermic reaction
When thefuel is a hydrocarbon then water andcarbondioxidearetheproducts formed
incomp conbustion
Someofthefueldoes not undergocombustion andunburnedhydrocarbons arereleased
intotheatmosphere
Itoccurs in someappliances such as boilers andstoves as well as in internal combustion
engines
In addition towater, carbon particles (soot) andcarbon monoxidemaybeproducedduring
incompletecombustion
what does combustion of fuel produce
Theburningoffossilfuels releases thegases carbondioxide, carbon monoxide,oxides of
nitrogen andoxides of sulfur
In addition, incompletecombustion ofthefuels gives risetounburned hydrocarbons and
carbonparticulates
