Global Warming Will Human-Induced Climate Change Destroy the World? By Rich Deem www.GodAndScience.org Note: This slideshow is NOT meant to be printed. View in slideshow mode only because of extensive builds and animations. Go to the website for a printable copy. Requires PowerPoint 2003 or PowerPoint Viewer 2003.
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Global Warming Will Human-Induced Climate Change Destroy the World? By Rich Deem Note: This slideshow is NOT meant to be printed.
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Global WarmingWill Human-Induced Climate Change Destroy the World?
By Rich Deemwww.GodAndScience.org
Note: This slideshow is NOT meant to be printed. View in slideshow mode only because of extensive builds and animations. Go to the website for a printable copy.
Requires PowerPoint 2003 or PowerPoint Viewer 2003.
IntroductionIntroduction
• Is the world getting warmer?
• If so, are the actions of mankind to blame for earth’s temperature increases?
• What can/should be done about these issues?
• Are the potential resolutions worth the cost to implement them?
History of Earth’s ClimateHistory of Earth’s Climate
• Earth formed ~4.6 billion years ago• Originally very hot• Sun’s energy output only 70% of
present• Liquid water present ~4.3 billion years
ago (zircon dating)• Much of earth’s early history erased
during late heavy bombardment (~3.9 billion years ago)
History of Earth’s ClimateHistory of Earth’s Climate
• Life appeared ~3.8 billion years ago• Photosynthesis began 3.5-2.5 billion
years ago Produced oxygen and removed carbon
dioxide and methane (greenhouse gases) Earth went through periods of cooling
(“Snowball Earth”) and warming
• Earth began cycles of glacial and interglacial periods ~3 million years ago
• Increasing CO2 emissions, especially in China and developing countries
• Likely to double within 150 years: Increased coal usage Increased natural gas usage Decreased petroleum usage (increased
cost and decreasing supply)
Kyoto ProtocolKyoto Protocol
• Adopted in 1997
• Cut CO2 emissions by 5% from 1990 levels for 2008-2012
• Symbolic only, since cuts will not significantly impact global warming
Past Temperatures
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1880 1900 1920 1940 1960 1980 2000Year
M
ean
Tem
per
atu
re (
°C)
Recorded Worldwide Temperatures
Recorded Worldwide Temperatures
FlatDecreasing
Flat
Winter Temperatures
10
11
12
13
14
15
16
17
1880 1900 1920 1940 1960 1980 2000
Year
Summer Temperatures
18
19
20
21
22
23
24
25
1880 1900 1920 1940 1960 1980 2000
Year
Annual Temperatures
15
16
17
18
19
20
21
22
1880 1900 1920 1940 1960 1980 2000
Year
Tem
per
atu
re (
°C)
Historic Los Angeles Temperatures
Historic Los Angeles Temperatures
2009 Temperature Changes Compared to 1951-1980
2009 Temperature Changes Compared to 1951-1980
-4.1 -4 -2 -1 -.5 -.2 .2 .5 1 2 4 4.1
2009 Temperature Changes Compared to 1951-1980
Past Temperatures MeasurementPast Temperatures Measurement
• Proxy – a method that approximates a particular measurement (e.g., temperature) Tree rings Ice cores Pollen records Plant macrofossils Sr/Ca isotope data Oxygen isotopes from speleothem calcite
(stalactites and stalagmites)
Temperature History of the EarthTemperature History of the Earth• Little ice age (1400-1840) – 1°C cooler • Medieval warm period (800-1300) – 1°C
warmer than today• Cool/warm cycles occur ~1,500 years• Affect mostly Northeastern U.S. and North
Atlantic• Mostly due to changes in thermohaline
circulation • Dramatic shutdown of thermohaline
circulation occurred 8,200 years ago as a large lake in Canada flooded the North Atlantic
Main Ocean CurrentsMain Ocean Currents
Adapted from IPCC SYR Figure 4-2
Temperature History of the EarthTemperature History of the Earth
• For the past 3 million years, the earth has been experiencing ~100,000 year long cycles of glaciation followed by ~10,000 year long interglacial periods
• These climate periods are largely the result of cycles in the earth’s orbit – precession, obliquity, and eccentricity
Orbital Parameters: PrecessionOrbital Parameters: Precession
PerihelionApehelion
Orbital Parameters: ObliquityOrbital Parameters: Obliquity22.5°24.5°
Orbital Parameters: EccentricityOrbital Parameters: Eccentricity
PerihelionApehelionApehelion
Minimum: 0.005Minimum: 0.005
Maximum: 0.061Maximum: 0.061
Not to scale!Not to scale!To Scale!To Scale!
Orbital Parameters & Earth’s ClimateOrbital Parameters & Earth’s Climate
Temperature History of the EarthTemperature History of the Earth
• For the past 3 million years, the earth has been experiencing ~100,000 year long cycles of glaciation followed by ~10,000 year long interglacial periods
• Last ice age began to thaw 15,000 years ago, but was interrupted by the “Younger Dryas” event 12,900 years ago
YoungerDryas
YoungerDryas
Younger Dryas EventYounger Dryas Event
-55-55
-50-50
-45-45
-40-40
-35-35
-30-30
-25-25
05101520Age (kya)
Tem
per
atu
re (
°C)
Tem
per
atu
re (
°C)
0.050.05
0.100.10
0.150.15
0.200.20
0.250.25
0.300.30
0.350.35
Sn
ow
Acc
um
ula
tio
n (
m/y
r)S
no
w A
ccu
mu
lati
on
(m
/yr)
Little Ice AgeLittle Ice AgeIce Age
Medieval WarmMedieval Warm
Younger Dryas EventYounger Dryas Event
-44-44-43-43-42-42
-41-41-40-40-39-39-38-38-37-37
-36-36-35-35-34-34
18O
(G
reen
lan
d)
18O
(G
reen
lan
d)
-8.0-8.0
-7.5-7.5
-7.0-7.0
-6.5-6.5
-6.0-6.0
-5.5-5.5
-5.0-5.0
-4.5-4.5
-4.0-4.010111213141516
18O
(C
hin
a)18
O (
Ch
ina)
YoungerDryas
YoungerDryas
Age (kya)
Temperature History of the EarthTemperature History of the Earth
Middle Pliocene (3.15 to 2.85 million ya)
• Temperatures: 2°C higher than today. 20°C higher at high latitudes 1°C higher at the Equator
• Sea levels were 100 ft higher
• Causes CO2 levels that were 100 ppm higher
Increased thermohaline circulation
Temperature History of the EarthTemperature History of the Earth
Eocene (41 million years ago)
• Opening of the Drake Passage (between South America and Antarctica).
• Increased ocean current exchange Strong global cooling First permanent glaciation of Antarctica
~34 million years ago
Temperature History of the EarthTemperature History of the Earth
Paleocene Thermal Maximum (55 mya)
• Sea surface temperatures rose 5-8°C
• Causes Increased volcanism Rapid release of methane from the oceans
Temperature History of the EarthTemperature History of the Earth
Mid-Cretaceous (120-90 mya)
• Much warmer
• Breadfruit trees grew in Greenland
• Causes Different ocean currents (continental
arrangement) higher CO2 levels (at least 2 to 4 times
higher than today, up to 1200 ppm)
Breecker D O et al. PNAS 2010;107:576-580
6000
5000
4000
3000
2000
1000
030
60
90
Atm
ospheric CO
2
Concentration (ppm
V)C
ontinental Glaciation
(Paleolatitude)
400 300 200 100 0Paleozoic Mesozoic Cenozoic
S D Carb P Tr J K Pg Ng
A Compilation of Phanerozoic Atmospheric CO2 Records
A Compilation of Phanerozoic Atmospheric CO2 Records