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Evidence
370
365360355350
345
340335330
325
320315310
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
370
365360355350
345
340335330
325
320315310
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
Carbon Dioxide at Mauna Loa, HawaiiCarbon Dioxide at Mauna Loa, Hawaii
Global surface temperatureGlobal surface temperatureGlobal surface temperatureGlobal surface temperature
2000
14.5
14.4
14.3
14.2
14.1
14.0
13.9
13.8
13.7
13.6
13.5
13.4
58.0
57.8
57.6
57.4
57.2
57.0
56.8
56.6
56.4
56.2
1840 1860 1880 1900 1920 1940 1960 1980 2000
14.5
14.4
14.3
14.2
14.1
14.0
13.9
13.8
13.7
13.6
13.5
13.4
58.0
57.8
57.6
57.4
57.2
57.0
56.8
56.6
56.4
56.2
1840 1860 1880 1900 1920 1940 1960 1980
370
360
350
340
330
320
310
300
290
20001860 1880 1900 1920 1940 1960 1980
Carbon Dioxide ConcentrationsCarbon Dioxide Concentrations
Ice Core Data Mauna Loa(Hawaii)
Par
ts p
er m
illi
on
20001860 1880 1900 1920 1940 1960 1980
14.4
14.3
14.2
14.1
14.0
13.9
13.8
13.7
13.6
13.5
57.92
57.74
57.56
57.38
57.20
57.02
56.84
56.66
56.48
56.30
C F
Global Average TemperatureGlobal Average TemperatureGlobal Average TemperatureGlobal Average Temperature
150 100 50 0
2
0
-2
-4
-6
300
250
200
-4
-6
Thousands of years ago
Tem
per
atu
re c
han
ge
( °c
)
Car
bo
n d
ioxi
de
(pp
mv)
Temperature Change ( °c)
CO2 Concentration(Antarctic Ice Core)
CurrentLevel
Level1800AD
Atmospheric Carbon Dioxide Concentration and Temperature change
• Clear correlation Clear correlation between atmospheric between atmospheric CO2 and temperature CO2 and temperature over last 160,000 yearsover last 160,000 years
• Current level of CO2 is Current level of CO2 is outsideoutside bounds of bounds of natural variabilitynatural variability
• RateRate of change of CO2 of change of CO2 is also unprecedentedis also unprecedented
• Clear correlation Clear correlation between atmospheric between atmospheric CO2 and temperature CO2 and temperature over last 160,000 yearsover last 160,000 years
• Current level of CO2 is Current level of CO2 is outsideoutside bounds of bounds of natural variabilitynatural variability
• RateRate of change of CO2 of change of CO2 is also unprecedentedis also unprecedented
1 50 1 00 5 0 0
2
0
-2
-4
-6
300
250
200
400
500
600
700
750
Thousands of years ago
Tem
per
atu
re c
han
ge
( °c
)
Car
bo
n d
ioxi
de
(pp
mv)
Temperature Change through timeCompares to the present temperature
CurrentLevel
Atmospheric Carbon Dioxide Concentration and Temperature change
CurrentLevel
2100
CO2 Concentration in theatmosphere (Antarctic Ice Core)
If nothing is done to slowgreenhouse gas emissions...
• CO2 concentrations will likely be more than 700 ppm by 2100
• Global average temperatures projected to increase between 2.5 – 10.4°F
If nothing is done to slowgreenhouse gas emissions...
• CO2 concentrations will likely be more than 700 ppm by 2100
• Global average temperatures projected to increase between 2.5 – 10.4°F
Impacts of Global Warming
Sea-Level RiseSea-Level Rise
Global warmingGlobal warming(temperature increase)(temperature increase)
Effects of global warming on water cycleEffects of global warming on water cycle
Speeds up globalSpeeds up globalwater cyclewater cycle
More extreme weather eventsMore extreme weather events• DroughtsDroughts• StormsStorms• FloodsFloods
HealthWeather-related mortalityInfectious diseasesAir-quality respiratory illnesses
AgricultureCrop yieldsIrrigation demands
Water ResourcesChanges in water supplyWater qualityIncreased competition for water
Coastal AreasErosion of beachesInundation of coastal landsCosts to protect coastal communities
ForestsChange in forest compositionShift geographic range of forestsForest health and productivity
Species and Natural AreasShift in ecological zonesLoss of habitat and species
Potential Climate Change ImpactsPotential Climate Change ImpactsPotential Climate Change ImpactsPotential Climate Change Impacts
Sea Level Rise
Temperature
Precipitation
What can we do?
