climate change and ozone loss climate change review session climate change review session brian...
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Climate Change and Ozone LossClimate Change and Ozone Loss
Climate ChangeReview session
Climate ChangeReview session
Brian Kaestner and Dr. Richard ClementsBrian Kaestner and Dr. Richard Clements
Key ConceptsKey Concepts
How does the Earth’s climate fluctuate How does the Earth’s climate fluctuate
What factors affect climate What factors affect climate
What are the possible effects of global warming What are the possible effects of global warming
What can humans do about potential climate change
What can humans do about potential climate change
Past Climate ChangePast Climate Change
Past globaltemperatures
Past globaltemperatures
Recent trends in global temperatures
Recent trends in global temperatures
Average temperature over past 900,000 yearsAverage temperature over past 900,000 years
Thousands of years agoThousands of years ago900900 800800 700700 600600 500500 400400 300300 200200 100100 PresentPresent
Av
era
ge
su
rfa
ce
te
mA
ve
rag
e s
urf
ac
e t
em
pe
ratu
re (
°C)
pe
ratu
re (
°C)
991010
1111
1212
1313
14141515
1616
1717
Av
era
ge
su
rfa
ce
te
mp
era
ture
(°C
)A
ve
rag
e s
urf
ac
e t
em
pe
ratu
re (
°C) Average temperature over past 130 yearsAverage temperature over past 130 years
YearYear18601860 18801880 19001900 19201920 19401940 19601960 19801980 20002000 20202020
13.613.6
13.813.8
14.014.0
14.214.2
14.414.4
14.614.6
14.814.8
15.015.0
Average temperature over past 900,000 years
Thousands of years ago
Ave
rag
e su
rfac
e te
mp
erat
ure
(°C
)
900 800 700 600 500 400 300 200 100 Present9
10
11
12
13
14
15
16
17
Temperature change over past 22,000 years
Years ago
Tem
per
atu
re c
han
ge
(°C
)
20,000 10,000 2,000 1,000 200 100 Now
-5
-4
-3
-2
-1
0
1
2
End oflast iceage
Agriculture established
Average temperature over past10,000 years = 15°C (59°F)
Temperature change over past 1,000 years
Year
Tem
per
atu
re c
han
ge
(°C
)
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2101
-1.0
-0.5
0.0
0.5
1.0
Average temperature over past 130 years
Year
Ave
rag
e su
rfac
e te
mp
erat
ure
(°C
)
1860 1880 1900 1920 1940 1960 1980 2000 2020
13.6
13.8
14.0
14.2
14.4
14.6
14.8
15.0
The Natural Greenhouse EffectThe Natural Greenhouse Effect
Greenhouse effectGreenhouse effect Greenhouse gasesGreenhouse gases
Rays of sunlight penetrate Rays of sunlight penetrate the lower atmosphere and the lower atmosphere and warm the earth's surface.warm the earth's surface.
The earth's surface absorbs much of The earth's surface absorbs much of the incoming solar radiation and the incoming solar radiation and degrades it to longer-wavelength degrades it to longer-wavelength infrared radiation (heat), which rises infrared radiation (heat), which rises into the lower atmosphere. Some of into the lower atmosphere. Some of this heat escapes into space and some this heat escapes into space and some is absorbed by molecules of is absorbed by molecules of greenhouse gases and emitted as greenhouse gases and emitted as infrared radiation, which warms the infrared radiation, which warms the lower atmosphere.lower atmosphere.
As concentrations of greenhouse As concentrations of greenhouse gases rise, their molecules gases rise, their molecules absorb and emit more infrared absorb and emit more infrared radiation, which adds more heat radiation, which adds more heat to the to the lower atmosphere.lower atmosphere.
(a)(a) (b)(b) (c)(c)
Carbon dioxide
Temperaturechange End of
last ice age
160 120 80 40 0Thousands of years before present
Co
nc
entr
ati
on
of
carb
on
dio
xid
ein
th
e a
tmo
sph
ere
(p
pm
)
180
200
220
240
260
280
300
320
340
360
380
–10.0
–7.5
–5.0
–2.5
0
+2.5
Va
riat
ion
of
tem
pe
ratu
re (
˚C)
fro
m c
urr
en
t le
vel
Carbon dioxide (CO2)
Year1800 1900 2000 2100
260
310
360
410P
arts
per
mil
lio
n
Methane (CH4)
Year1800 1900 2000 2100
0.6
1.2
1.8
2.4P
arts
per
mil
lio
n
Year1990 2000 2025 2050 2075 2100
100
150
200
250
Ind
ex
(19
00
= 1
00
)Carbon dioxide
MethaneNitrous oxide
Human Activities and Earth’s ClimateHuman Activities and Earth’s Climate
Action-Increased use of fossil fuelsAction-Increased use of fossil fuels-Deforestation -Deforestation
CausesGlobal warmingCausesGlobal warming
Leads to-Melting icecaps and glaciersLeads to-Melting icecaps and glaciers-Coral reef bleaching-Coral reef bleaching
Projecting Future Changes in Earth’s ClimateProjecting Future Changes in Earth’s Climate
Climate models Climate models
Apparent influence of human activities
Apparent influence of human activities
Could be natural changes
Could be natural changes
YearYear18601860 18801880 19001900 19201920 19401940 19601960 19801980 20002000 20102010
-0.2-0.2
0.00.0
0.20.2
0.40.4
0.60.6
0.80.8
1.01.0
1.21.2Observed
Model of greenhouse gases + aerosols + solar output
Tem
per
atu
re c
han
ge
(°C
) fr
om
198
0–9
9 m
ean
Tem
per
atu
re c
han
ge
(°C
) fr
om
198
0–9
9 m
ean
Factors Affecting Changes in Earth’s Average TemperatureFactors Affecting Changes in Earth’s Average Temperature
Changes in solar output Changes in solar output
Changes in Earth’s albedo Changes in Earth’s albedo
Moderating effect of oceans
Moderating effect of oceans
Clouds and water vapor Clouds and water vapor
Air pollution Air pollution
Oceans 5%
Bare sand 30–60%
Grass 15–25%
Clouds50–55%
Snow80–90%
City 10–15%
Forest 5%
Antarctica
Cold water melting fromAntarctica's ice cap and
icebergs falls to the ocean floor and surges northward, affecting
worldwide circulation.
Cold water melting fromAntarctica's ice cap and
icebergs falls to the ocean floor and surges northward, affecting
worldwide circulation.
GreenlandGreenland
Today’s sea level
Years before present Present
250,000 200,000 150,000 100,000 50,000 0
–130
0
–426
0
Hei
gh
t ab
ove
or
bel
ow
pre
sen
t se
a le
vel
(met
ers)
Hei
gh
t b
elo
w p
rese
nt
sea
leve
l (f
eet)
Presentrange
Futurerange
Overlap
Climate zonesMove 60-90 milesPer 1Degree C
Tree speciesCan migrateAbout 5 milesPer decade
Some Possible Effects of a Warmer WorldSome Possible Effects of a Warmer World
• Increased deaths from heat and disease
• Disruption of food and water supplies
• Spread of tropical diseases to temperate areas
• Increased respiratory disease
• Increased water pollution from coastal flooding
Human Health
• Rising sea levels• Flooding of low-lying
islands and coastal cities• Flooding of coastal
estuaries, wetlands, and coral reefs
• Beach erosion• Disruption of coastal
fisheries• Contamination of coastal
aquifiers with salt water
Sea Level and Coastal Areas
• Changes in forest composition and locations
• Disappearance of some forests
• Increased fires from drying
• Loss of wildlife habitat and species
Forests
• Changes in water supply
• Decreased water quality
• Increased drought
• Increased flooding
Water Resources
• Shifts in food-growing areas
• Changes in crop yields
• Increased irrigation demands
• Increased pests, crop diseases, and weeds in warmer areas
Agriculture
• Extinction of some plant and animal species
• Loss of habitats
• Disruption of aquatic life
Biodiversity
• Prolonged heat waves and droughts
• Increased flooding
• More intense hurricanes, typhoons, tornadoes, and violent storms
Weather Extremes
• Increased deaths
• More environmental refugees
• Increased migration
Human Population
N
S
Waste less waterDevelop crops that need less water
Move hazardous material storage tanks away from coast
Prohibit new construction on low-lying coastal areas
Stockpile 1 to 5 year supply of key foods
Expand existing wildlife reserves toward poles
Connect wildlife reserves with corridors
Solutions: Dealing with the Threat of Climate ChangeSolutions: Dealing with the Threat of Climate Change
OptionsOptions
Do nothing Do nothing
Do more research Do more research
Act now to reduce risks
Act now to reduce risks
Prevention Cleanup
Cut fossil fueluse (especiallycoal)
Shift from coalto natural gas
Transfer energyefficiency andrenewable energytechnologiesto developingcountries
Improve energyefficiency
Shift torenewableenergy resources
Reducedeforestation
Use sustainableagriculture
Slow populationgrowth
Remove CO2
from smokestackand vehicleemissions
Store (sequesterCO2 by plantingtrees)
Sequester CO2
underground
Sequester CO2 in soil
Sequester CO2 in deep ocean