TIN206 - Pengetahuan Lingkungan Materi #10 TIN206 Genap 2015/2016. Global Warming. Will Human-Induced Climate Change Destroy the World?

(1)

Global Warming

Will Human-Induced Climate Change

Destroy the World?

Sumber: Rich Deem,

www.GodAndScience.org

Materi #10 – TIN206 – Pengetahuan Lingkungan

Introduction

• 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?

(2)

History 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)

Materi #10 TIN206 Genap 2015/2016 TIN206 - Pengetahuan Lingkungan 3

History 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

(3)

Sun

Earth’s Temperature

Solar

Energy

Solar

Energy

Materi #10 TIN206 Genap 2015/2016

5 TIN206 - Pengetahuan Lingkungan

Sun

Earth’s Temperature

Solar

Energy

Radiative

Cooling

(4)

Sun

Earth’s Temperature

Solar

Energy

Radiative

Cooling

7

Sun

Earth’s Temperature

Solar

Energy

Radiative

Cooling

(5)

Greenhouse Effect

Sun

Earth’s Atmospheric Gases

Nitrogen (N

₂

)

Oxygen (O

₂

)

Water (H

₂

O)

Carbon Dioxide (CO

₂

)

99%

Methane (CH

₄

)

1%

Non-Greenhouse

Gases

Greenhouse

Gases

Materi #10 TIN206 Genap 2015/2016 10 TIN206 - Pengetahuan Lingkungan

(6)

Sun

Runaway Greenhouse Effect

• 97% carbon dioxide

• 3% nitrogen

• Water & sulfuric acid

clouds

• Temperature:

860°F

Venus

Materi #10 TIN206 Genap 2015/2016 11 TIN206 - Pengetahuan Lingkungan

(7)

170

220

270

320

370

420 200000

400000

600000

Time (YBP)

CO

2 (ppm

)

Vostok Ice Core

Dome Concordia

Carbon Dioxide Levels

0 Muana Loa Readings

CO

₂

Levels Since 1958

310

330

350

370

10

20

30

40 CO

2 (ppm

)

0 Worldwide Carbon Emissions

Car

bo

n

(10

9 met

ric

t

ons)

0

1

2

3

4

5

6

7

8 1750

1800

1850

1900

1950

2000

Year

Liquid fuel

Total

Gas fuel

Solid fuel

(8)

Annual Carbon Emissions

Annual carbon emissions

Atmospheric CO

₂

Atmospheric CO

₂

average

1955

0 1965

1975

1985

1995

2005

4

6

8

2 Year

Car

bo

n

(10

9 met

ric

t

ons)

Future Carbon Dioxide Levels

• Increasing CO

₂

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)

(9)

Kyoto Protocol

• Adopted in 1997

• Cut CO

₂

emissions by 5% from 1990

levels for 2008-2012

• Symbolic

only, since

cuts

will

not

significantly impact global warming

(10)

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8 1880

1900

1920

1940

1960

1980

2000

Year

D

M

ea

n

T

emper

a

tur

e (

°C)

Recorded Worldwide

Temperatures

Flat

Decreasing

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

T e m p e rat u re ( °C)

Historic Los Angeles

Temperatures

(11)

-3

-2.5 -1.5

-1

-.5

-.1

.1

.5

1

1.5

2.5

3.4 2007 Temperature Changes

Compared to 1951-1980

Past Temperatures Measurement

• Proxy – a method that approximates a

particular measurement (e.g., temperature)

 Ice cores

 Pollen records

 Plant macrofossils

 Sr/Ca isotope data

 Oxygen isotopes from speleothem calcite

(stalactites and stalagmites)

(12)

Temperature 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 Currents

Adapted from IPCC SYR Figure 4-2

(13)

Temperature 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: Precession

Perihelion

Apehelion

(14)

Orbital Parameters: Obliquity

22.5°

24.5°

Orbital Parameters: Eccentricity

Perihelion

Apehelion

Minimum: 0.005

Maximum: 0.061

Not to scale!

To Scale!

(15)

Orbital Parameters & Earth’s Climate

Age (kya)

1000900800 700 600 500 400 300 200 100 0

Eccentricity

(100 ky)

Temperature

Obliquity

(41 ky)

Precession

(22 ky)

Temperature 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

(16)

Younger

Dryas

Younger Dryas Event

-55

-50

-45

-40

-35

-30

-25

0

5

10

15

20 Age (kya)

T

emper

a

tur

e

(°

C)

0.05

0.10

0.15

0.20

0.25

0.30

0.35 Sno

w

A

ccumula

ti

o

n

(m/yr)

Little Ice Age

Ice Age

Medieval Warm

Younger Dryas Event

-44

-43

-42

-41

-40

-39

-38

-37

-36

-35

-34

d

18 O

(G

ree

nla

nd)

-8.0

-7.5

-7.0

-6.5

-6.0

-5.5

-5.0

-4.5

-4.0

10

11

12

13

14

15

16 d

18 O

(Ch

in

a

)

Younger

Dryas

Age (kya)

(17)

Temperature 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

 CO

₂

levels that were 100 ppm higher

 Increased thermohaline circulation

Temperature 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

(18)

Temperature 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 Earth

Mid-Cretaceous (120-90 mya)

• Much warmer

• Breadfruit trees grew in Greenland

• Causes

 Different ocean currents (continental

arrangement)

 higher CO

₂

levels (at least 2 to 4 times higher

than today, up to 1200 ppm)

(19)

Recent Temperature Changes

“Hockey Stick” Controversey

1000

1200

1400

1600

1800

2000

-0.8

Year

-0.6

-0.4

-0.2

0

0.2

0.4

0.6 T

empe

ra

tu

re

Cha

n

ge

(°

C)

_{Direct temperature measurements}

(20)

Mann et al. 1999

Esper et al. 2002

800 1000

1200

1400

1600

1800

-2

-1

0

1

2 T

em

p

er

a

tu

re Ch

a

nge (

°C)

2000

Year

Is the Hockey Stick Correct?

-1.2

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0

400

800 1200

1600

2000

Year

T

emper

a

tu

re

Cha

ng

e

(°

C)

Mann et al. 1999

Esper et al. 2002

Moberg et al. 2005

Mann et al. 2008

(21)

U.S. National Academy of Sciences:

June 2006

1000

1200

1400

1600

1800

2000

-0.8

Year

-0.6

-0.4

-0.2

0

0.2

0.4

0.6 T

empe

ra

tu

re

Cha

n

ge

(°

C)

“high level of confidence”

“2:1 chance of being right”

-1.0

-0.5

0.0

0.5

1.0

1.5 1980

1990

2000

Year

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8 1980

1990

2000

Year

T

emper

a

tur

e

C

g

a

n

ge

(°

C)

Atmospheric Temperatures

Troposphere

Stratosphere

(22)

170

220

270

320

370

0 200000

400000

600000

Time (YBP)

CO

2 (p

p

m)

Ant

ar

ctica

25

26

27

28

29

30

31 SS

T (

°C)

T

ropical

P

ac

ific

CO

₂

Concentration Vs. Temperature

Consequences of Global

Warming

(23)

Global Warming Primarily Impacts

the Northern Hemisphere

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0 1920

1960

2000

Year

T

emp

er

at

ur

e

C

hange

(°

C)

1920

1960

2000

Year

Northern vs. Southern Latitude

Land vs. Ocean

Northern Hemisphere

Southern Hemisphere

Land

Ocean

2007 Temperature Changes

Compared to 1951-1980

-3

-2.5 -1.5

-1

-.5

-.1

.1

.5

1

1.5

2.5

3.4

(24)

Ice Sheets Melting?

• GRACE (gravity measured by satellite) found

melting of Antarctica equivalent to sea level

rise of 0.4 mm/year (2 in/century)

• Zwally, 2005 (satellite radar

altimetry)

 confirmed Antarctica melting

 Greenland ice melting on

exterior, accumulating inland

(higher precipitation)

Melting Glaciers – Mt. Kilimanjaro

(25)

1000

800

600

400

200

0 -200

-400

-600

2003

2004

2005

Ic

e

Ma

ss

(km

3 )

Year

Changes in Antarctica Ice Mass

Rise in Sea Levels?

• Present rate is 1.8 ± 0.3 mm/yr (7.4

in/century)

• Accelerating at a rate of 0.013 ± 0.006

mm/yr

2 • If acceleration continues, could result in

12 in/century sea level rise

• Scenarios claiming 1 meter or more rise

are unrealistic

(26)

Changing Sea Levels

1700

1750

1800

1850

1900

1950

2000

-20

-10

0

10

20 R

elat

iv

e

S

ea

L

e

v

el (

cm)

Adapted from IPCC SYR Figure 2-5

Amsterdam, Netherlands

Brest, France

Swinoujscie, Poland

Glo

bal

T

em

per

at

ur

e

Chan

ge

Time (KYBP)

S

ea Le

v

el

(

m)

20

0 -20

-40

-60

-80

-100

-120

Sea Levels for 450,000 Years

450 400 350 300 250 200 150 100 50

0

25

26

27

28

29

30

31 SS

T (

°C)

T

ropical

P

ac

ific

(27)

Increase in Hurricanes?

• Two studies showed the total number of

hurricanes has not changed

• However, the intensity of hurricanes has

increased (more category 4 and 5

hurricanes and cyclones)

• Probably due to higher sea surface

temperatures (more energy)

• Difficult to know if this trend will

continue

1860 1880 1900 1920 1940 1960 1980 2000 2020

0

5

10

15 Data Unreliable

Scaled August-October

Sea-Surface Temperature

Adjusted Atlantic Storm

Power Dissipation Index

SS

T/SPDI

(met

ers

3 /sec

2 )

How Much Temperature Increase?

• Some models propose up to 9°C increase

this century

• Two studies put the minimum at 1.5°C

and maximum at 4.5°C or 6.2°C

• Another study puts the minimum at

2.5°C

(28)

Wildlife Effects

• Polar Bears

 Require pack ice to live

 Might eventually go extinct in the wild

• Sea turtles

 Breed on the same islands as

their birth

 Could go extinct on some islands

as beaches are flooded

• Other species may go extinct as rainfall patterns

change throughout the world

Effect on Humans

• Fewer deaths from cold, more from heat

• Decreased thermohaline circulation

 Cooler temperatures in North Atlantic

• CO

₂

fertilization effect

• Precipitation changes

 Droughts and famine (some areas)

 Expanded arable land in Canada, Soviet

Union

(29)

Potential Worldwide Precipitation

Changes

-50

-20

-10

-5

5

10

20

50 Drought in Africa

Lake Faguibine

Lake Chad

(30)

Cost to Stabilize CO

₂

Concentrations

450

550

650

750 1800

1600

1400

1200

1000

800

600

400

200

0 Carbon Dioxide (ppm)

C

o

st

(

T

ri

llo

n

s

U

.S.

Dol

la

rs

)

Possible Solutions to

Global Warming

(31)

Mitigation of Global Warming

• Conservation

 Reduce energy needs

 Recycling

• Alternate energy sources

 Nuclear

 Wind

 Geothermal

 Hydroelectric

 Solar

 Fusion?

Storage of CO

₂

in Geological Formations

1. Depleted oil and gas reservoirs

2. CO

2

in enhanced oil and gas recovery

3. Deep saline formations – (a) offshore (b) onshore

4. CO

2

in enhanced coal bed methane recovery

3a

2

(32)

Conclusions

• Global warming is happening

• Most warming is probably the result of

human activities

• There will be positive and negative

(mostly)

repercussions

from

global

warming

• The costs to mitigate global warming will

be high – better spent elsewhere?