This document discusses the science of climate change and its impacts. It provides evidence that the climate has fluctuated naturally in the past but is now changing due to human activity like burning fossil fuels. This is increasing greenhouse gases and global temperatures, causing sea ice and glaciers to melt, sea levels to rise, and more extreme weather. If emissions are not reduced, significant global impacts are projected this century like worse droughts and storms, flooded coastlines, and threatened ecosystems and food supplies.

1. GLO
BAL
WARM
ING

2. Climate changes

3. Climate changes
18,000 years ago
Present
Glacier ice
Sea ice

4. Florida’s coast during the LGM
Climate change has effects
18,000 years ago

5. Warming
Fluctuate
with
climate:
• Temperature
(pa+erns)
• Ice
cover
• Sea
level
• Precipita7on
(pa+erns)
• Vegeta7on
cover

6. Essen1al
Principles
of
Climate
Science

7. 1.
The
Sun
is
the
primary
source
of
energy
for
Earth’s
climate
system

8. Naturally,
heat-­‐trapping
gases
in
the
atmosphere
keep
the
Earth’s
surface
warm
Human
ac1vi1es
are
increasing
the
concentra1ons
of
some
of
these
gases,
amplifying
the
natural
greenhouse
effect

9. 2.
Climate
is
regulated
by
complex
interac1ons
among
various
systems

10. Humans

11. 46

12. 47

13. 3.
Life
on
Earth
depends
on,
is
affected
by,
and
affects
climate

14. 4.
Climate
varies
over
space
and
1me
through
both
natural
and
human
processes
Muir
glacier,
Alaska
August
1941
Muir
glacier,
Alaska
August
2004

15. 5.
Our
understanding
of
the
climate
system
is
improved
through
observa1ons,
theore1cal
studies,
and
modeling

16. 6.
Human
ac1vi1es
are
impac1ng
the
climate
system

17. 7.
Climate
change
will
have
consequences
on
the
Earth
system
and
human
life

19. 1824:
Jean-­‐Bap1ste
Fourier
discusses
greenhouse
effect

20. 1861:
John
Tyndall
Publishes
that
CO2
and
H2O
are
greenhouse
gasses

21. 1896:
Svante
Arrhenius
proposed
anthropogenic
greenhouse
effect;
burning
fossil
fuels
will
build-­‐up
CO2
and
lead
to
“desirable”
warming

22. 1938:
G.S.
Callendar
argues
that
anthropogenic
warming
is
underway

23. 1956:
Gilbert
Plass
calculates
that
CO2
emissions
will
have
a
significant
effect
on
Earth’s
radia<on
balance,
3°F
by
end
of
century

24. 1957:
Roger
Revelle
warns
"large-­‐scale
geophysical
experiment”;
he
and
David
Keeling
begin
monitoring
CO2

25. Atmospheric
CO2
(ppmv)
Present CO2
concentration
(391 ppmv)
!+#$
!*#$
!)#$
!(#$
!'#$
!&#$
!!#$
!%#$
!"#$
"+''$
"+('$
"+)'$
"+*'$
"++'$
%##'$

27. CO2 concentration
after 30 years of
unrestricted fossil fuel
burning (600 ppmv)
270
240
210
180
Temp.
Proxy
CO2 (ppmv)
300
350
Present CO2
concentration
(391 ppmv)
800
600
400
200
Thousands of Years Before Present
Petit et al., 1999; Siegenthaler et al., 2005; EPICA Community members, 2004
0

28. 1980s:
Warmest
decade
on
record

29. 1990s:
Warmest
decade
in
1000
years

30. Global Instrumental Temperature Record
1
Global Temperature anomalies (°C)
5-year running mean
0.8
Global Temperature Anomaly (ºC)
0.6
0.4
0.2
-0
-0.2
Smokin’
-0.4
Hottest decade
in 1000 years
-0.6
Hottest decade on record
-0.8
1880
1890
1900
1910
1920
1930
1940
1950
http://data.giss.nasa.gov/gistemp
1960
1970
1980
1990
2000
2010

31. Snow
in
the
desert?

32. Ice cover
Temperature

33. Ice cover
?
Temperature

35. Hysteresis
system that exhibits non-linear behavior

40. Arc1c
Sea
Ice
Mel1ng
1979

41. Arc1c
Sea
Ice
Mel1ng
2005

42. Arc1c
Sea
Ice
Mel1ng
2007

43. Arc1c
sea
ice
extent
Summer
Ice
Extent
(106
km2)
'"
&#$"
&"
%#$"
%"
$#$"
$"
!#$"
!"
()&$"
()'$"
())$"
*++$"
Source:
Na7onal
Snow
and
Ice
Data
Center

44. Arc1c
Warming
Temperature Anomaly (°C)
2.0
1.0
0.0
All land area
Arctic (land north of 65°N)
-1.0
1960
1980
2000

45. Larsen
B,
Mar-­‐02

46. Larsen
B,
Mar-­‐02

47. Larsen
B,
Mar-­‐02

48. Larsen
B,
Mar-­‐02

49. Larsen
B,
Mar-­‐02

50. Larsen
B,
Mar-­‐02

51. Larsen
B,
Mar-­‐02

52. Sea-level rise

54. Sea-­‐level
rise
1. Thermal
expansion
2. Mel3ng
small
glaciers
and
ice
caps
3. Freshening
of
water
4. Mel3ng
ice
sheets
•
•
Greenland:
7.4
m
(25’)
Antarc7ca:
74
m
(250’)
•
•
West
Antarc7ca
(7
m)
East
Antarc7ca
(67
m)

55. “
Those
of
us
who
live
on
small
specks
of
land
.
.
.
have
not
agreed
to
be
sacrificial
lambs
on
the
altar
of
success
of
industrial
civiliza1on.
Ambassador
Lionel
Hurst
of
An1gua
and
Barbuda
June
28,
2002
Photo by rembcc

56. McCarty
Glacier,
Alaska
2004
1909

57. Rhone
1900

58. Rhone
2008

59. Kilimanjaro
1993
2000

61. Qori
Kalis
1978
2002

62. Patagonia
1928
2004

63. 225’
25’
250’

64. Antarctic Warming (1957-2006)

65. R.
Huff,
J.
Box,
S.
Starkweather,
T.
Albert

66. Total
melt
area
Source:
Passive
Microwave
Satellite
Melt
Record

67. 2007 Melt-day anomaly
Microwave data from SSMI reveals
more melting days in 2007 than
during the period 1988–2006
Credit: NASA/Earth Observatory

68. Mass change on Greenland
200
Unfiltered data
Seasonally filtered data
0
Mass Change [Gt]
-200
-400
-600
-800
-1000
-1200
-1400
2007 Extreme Summer Melt
-1600
-1800
2003
2004
2005
2006
2007
2008
2009
Source: GRACE measurements

70. June
14,
2001

71. June
13,
2002

72. June
17,
2003

74. That’s
about
600,000
lbs
per
person
on
Earth!
Since
2003:
More
than
2
trillion
tons
of
ice
in
Greenland,
Antarc1ca
and
Alaska
has
melted

75. Sea-­‐level
rise

76. Sea-­‐level
rise

77. Sea-­‐level
rise

78. of
1m
can
increase
the
change
in
mean
sea
level
A
ore
than
1000
1mes.
y
of
extreme
events
by
m
frequenc

79. Coastal
popula1on

80. 25’
rise
in
sea
level

81. 250’
rise
in
sea
level

82. Manhaian

83. Manhaian
+26’

84. Manhaian
+26’

85. Consequences

86. 10
Data (CDIAC)
9
8
7
Model Scenarios
Fossil Fuel Emissions (Gigatonnes C / yr)
Depends
on
our
emissions
A1B
A1FI (Worst case?)
A1T
A2
B1
B2
6
5
1990
1995
2000
2005
2010

87. Global
average
temperatures
will
rise
1-­‐6°C
by
2100

88. Increased
diseases,
both
air-­‐borne
(e.g.
asthma)
and
insect-­‐
borne
(e.g.
malaria)

89. Over
1,000,000
species
face
ex1nc1on

91. More
extreme
weather:
Droughts
and
floods,
frosts
and
heat-­‐waves,
and
severe
storms

92. Severe
water
shortages,
especially
where
supply
depends
on
glaciers

93. Wide-­‐spread
hunger
due
to
drought
and
deser1fica1on

95. Numbers
of
CATEGORY
4
AND
5
storms
by
ocean
basin

96. Water
temperature
and
storms
severity
Atlantic Potential Destructive intensity (PDI)
0.4
Atlantic Storm Intensity (PDI)
0.2
Aug.-Oct. Sea Surface Temperatures (SST)
1.2
1.0
0.8
0.6
0.4
0.2
1940
1950
1960
1970
1980
1990
2000
2010
Emanuel, K. (2005), Increasing destructiveness of tropical cyclones over the past 30 years, Nature, 2005

97. Idealized
hurricane
simula1ons
(9
GCMs,
3
basins,
4
parameteriza1ons,
6-­‐member
ensembles)
160
Category 5
Category 4
Category 3
140
Number of occurrences
Control (mean = 934 mb)
120
High CO2 (mean = 924 mb)
100
80
60
40
20
0
880
900
920
940
Minimum central pressure (mb)
Knutson, T. K., and R. E. Tuleya, 2004, Journal of Climate.
960

98. 50%
Hurricanes are now 50% STRONGER and LONGER lasting
than 30 years ago

99. Coastal
flooding
and
storm
surges

100. Environmental
Refugees
Millions of people
150 (projected)
50 (projected)
25
1995
2010
Source: IPCC (2007)
2050

101. OTHER
HAZARDS
Glacial
quakes
Glacier
out-­‐burst
floods

102. What
can
we
do?

103. Plant
trees!

104. Reduce
consumpDon

106. Shop
smart

107. AlternaDve
energy

108. Biodiesel
Cleaner
Renewable
Reduced
emissions
Grown
on
US
farms
Reduce
dependence
on
foreign
oil
Increases
mileage,
power,
and
engine
life

109. Be
informed

110. Unplug

111. ncy
cie
e
effi
rov
Imp

112. Don’t
buy
ocean-­‐front
property

113. T
R
A
M
S

114. Form
PACs

115. Don’t
remain
happy
in
ignorance

116. todda@me.com