Where to Tan and Buy Beach Property: An Overview on Global Warming
Dennis BaldocchiProfessor of Biometeorology
Department of Environmental Science, Policy and Management&
Berkeley Atmospheric Science Center
Defend Science, April, 2006
Knowledge is Power
• Background– ‘Greenhouse-Effect’ Principles
• Historic and Current Observations– Methods– Trace Gases– Temperature– Sea Level and Sea Ice
• Model Predictions• Scientists Defending Global Warming
Physics of the Atmosphere
Climate Concepts
• Atmosphere is a Dynamic and Complex System– Multiple Positive and Negative Feedbacks that
operate across a Spectrum of Time and Space Scales– Non-Linear Processes– Sensitivity to Initial Conditions– Thresholds and Tipping Points
Schellnhuber, Tipping Point
Radiative Balance of Earth without an Atmosphere
Radiation intercepted by Earth equals thatradiated back into space.
(1-a)S*/4=T4
Solar constant, S*=1366 W m -2
albedo, a = 0.33
Trad~251 K = -22 C
Wavelength (microns)
1 10 100
Ab
sorp
tion
Cro
ss-S
ect
ion
(cm
-1/(
mo
lecu
le c
m-2
)
1e-21
1e-20
1e-19
1e-18
1e-17
H2O
CO2
HI-Tran Database
Many Atmospheric Trace Gases Absorb & Re-emit Infrared Radiation
Radiation Streams in a Greenhouse Atmosphere
Temperature of Earth with Atmosphere:Tsfc~288 K
Trends in Trace Gases:Ancient and Recent
Barnola et alVostok Ice Core
Y ears before Present
0 100000 200000 300000 400000
CO 2 (
pp
m)
160
180
200
220
240
260
280
300
320
Vostok Ice CorePetit et al. 1999 Nature
Y ears Before Present
0 100000 200000 300000 400000
Te
mp
era
tu
re
Va
ria
tio
n
-12
-10
-8
-6
-4
-2
0
2
4
Paleo- CO2 and Temperature Record
Vostok Ice CoreData of Petit et al
CO2 (ppm)
160 180 200 220 240 260 280 300
Te
mp
era
ture
An
om
ali
es
-10
-8
-6
-4
-2
0
2
4
Coefficients:b[0]: -25.77b[1]: 0.092r ²: 0.776
Changing CO2 Re-enforces T anomalies
Bender, GBC, 2003
Contemporary CO2 Record
Mauna LoaKeeling data
year
1950 1960 1970 1980 1990 2000 2010
CO
2 (
pp
m)
300
310
320
330
340
350
360
370
380
13C Isotope record: Evidence of Fossil Fuel CombustionAntarctic Ice Core(Francey et al. 1999)
Year
1300 1400 1500 1600 1700 1800 1900 2000 2100
13 C
-7.6
-7.4
-7.2
-7.0
-6.8
-6.6
-6.4
-6.2
-6.0
•Plant based Carbon has a 13C signature ~ -25 per mil
•Combustion of Fossil Fuels Dilutes the Atmospheric Background
Atmospheric CO2 Burden
Y ear
1950 1960 1970 1980 1990 2000 2010
Ch
an
ge
in
CO
2
(Gt
(10
15g
) p
er
ye
ar)
0
1
2
3
4
5
6
7
8
Rate of Change in Atmospheric CMauna Loa, data of KeelingFossil Fuel Emissionsdata of Marland et al.
average = 3.08 Gt C yr-1
std dev = 1.21 Gt C yr-1
Mt Pinatubo Eruption
Indonesia Fires
Evidence of Global Warming :Direct and Indirect Confirmation by Multiple Methods
• Observations– Climate Networks (~1850 to present)
• Air, Sea and Soil Temperature Networks– Phenology Networks
• Date of flowering (lilac, cherries, fruit trees)• Timing of grape harvest
– Sea Level– Tree Rings (~1000 to present)– Stable Isotopes
• Ice Cores (600 kyr BCE to present)• Oxygen isotope ratio (18O/16O) in calcium carbonate of
seashells (forams)– Satellite Observations
• Length of Growing Season (1970s to present)• Extent of Sea Ice
• Modeling– Global Circulation-Climate Models
• Diagostic• Prognostic
Temperature Anomaly Trends:Instrument Record
Waple et al 2002 BAMS
Courtesy of ME Mann, Penn State
Proxy Temperature Record:Tree Rings, Coral, sediments, ice cores
Climate Statistics:Mean vs Probablity Distribution
• Tropical Cyclones, Hurricanes• El Nino/La Nina• Extra-Tropical, Severe Winter Storms• Precipitation, Drought• Temperature, Extreme Heat and Cold• Floods, Winter Storms, Thunderstorms• Thunderstorms: Hail, Lightening, Fire,
Tornados
Hansen et al. 2005, JGR
Climate Proxy:Beginning of growing season and temperature in Germany
Chmielewski, AgForMet
Change in Arctic Ice and Greenland
NOAA/CIRES
Arctic Ice Extent
What’s Happening Locally?:Sea Level at Ft Point
http://pubs.usgs.gov/fs/1999/fs175-99/
-124 -123 -122 -121 -120 -119 -118 -117 -116 -115
33
34
35
36
37
38
39
40
41
42
-500 to -400
-400 to -300
-300 to -200
-200 to -100
-100 to -50
-50 to 0
Trends in W inter C hill H our Accum ulation (degree hours per year)N ov-M ar, 32 to 45 F
Baldocchi and Wong, 2006, Cal EPA Report
Future Conditions
Climate Model Refinements
• Sulfate aerosols• Transient Changes in Trace Gases
• Suite of Radiative trace gases, CO2, H2O, CFC, N2O
• Coupled ocean and atmosphere• Cloud/water vapor feedbacks• Finer Resolution, 19 layers, 250 km grid• Improved Land Surface schemes
– BATS, SIB-I, SIB-II, LSX
GFDL/NOAA
http://www.gfdl.gov/~rjs/stouffer_MBO.html
Sealevel Rise, GFDL,/NOAA
http://www.gfdl.gov/~tk/climate_dynamics/fig4.gif
Further Refinements
• Coupling Climate, Biogeochemistry and Ecosystem Dynamic models– Climate Change is needed to predict Vegetation
Changes– Changes in Vegetation affects land/surface
interactions and Climate– Mass and energy fluxes are constrained by links to
Biogeochemistry– Assess changes in landcover due to mankind
Defenders of Climate Science
• Michael Mann, Penn State
• James Hansen, NASA/GISS
Michael Mann, Penn State
– Was subject to criticism of ‘Hockey stick’ Climate data, which was featured in IPCC report
• McIntyre and McKitrick (2003, GRL), an Mining Executive and an Economistis falsely claim that the ‘hockey stick’ is an artifact of the use of series with infilled data and the convention by which certain networks of proxy data were represented
• Other Critics (von Storch, Science; Burger and Cubasch, GRL) detrended proxy data before calibration
– In 2005, Texas Representative Joe Barton, chair of the United States House of Representatives’ Energy and Commerce Committee and a global warming skeptic, demanded information on the location of data archives, computer codes, grant awards, and other research details from Mann and his hockey stick colleagues.
• Details are available at http://branch.ltrr.arizona.edu
– National Academy Science has been commission to report on paleoclimate reconstruction
• Mann expects that this report will reaffirm ours and other studies leading to the same common conclusion, that late 20th century warmth is anomalous in this context
www.realclimate.org
James Hansen, NASA/GISS
• Subject of 60 Minutes Interview and New York Times article on Restrictions by NASA for Scientists to communicate with Journalists and on having had research results and reports edited by Bush Administration staff.
• The new NASA guidelines prohibit the editing of reports to alter scientific data, as well as any public affairs management of NASA projects by non-agency institutions.
– NASA scientists may draw conclusions from their research and communicate them to the media, but "must make clear that they are presenting their individual views — not the views of the agency — and ask that they be sourced as such.“ (April 2, 2006)
• the new policy is a substantial improvement– "things have changed dramatically since this became
a public issue ... hopefully similar things will happen at other agencies that have had problems." (James Hansen)
Conclusions
• Climate system is inherently noisy, but Trends are Emerging– We view climate system with multiple tools at multiple time and space scales – Consistent and Repeatable Patterns are Arising
• Climate Forecasts are based on fundamental principles of Physics, Biology and Chemistry• Climate Change is Associated with many complex feedbacks
– Change can be slow at first, but accelerate later as ice-caps melt, albedo decreases and moisture in the atmosphere increases
• Science is Not Democratic– Hypotheses are Rejected and Accepted based on observation and theoretical principles
• Policy and Science– Society is holding Climate Change Scientists to a much Higher Burden of proof than for other economic and
political decisions (eg Weapons of Mass Destruction, War in Iraq, Purchase of stocks and bonds).– It is prudent and pre-cautionary to rely on the ability of scientifically-based models to predict trends through
and out of inherently noisy environmental signals in order to make effective policy– Penny wise versus Dollar Foolish
• The Long-Term costs of responding to unmitigated climate change could far exceed the current savings associated with doing nothing now(health, governmental stability);
– We need to Change How Business is Accounted by Internalizing Externalities. • The current cost of oil does not reflect the effects of climate change on societies and ecosystems
Climate Skeptics
• Senator James Inhofe, OK– ‘Global Warming is a Hoax’
• Michael Crichton, Author– State of Fear
• Patrick Michaels, State Climatologist, Virginia– "The American people have just been bludgeoned with climate
disaster stories for God knows how long," …"and they're just, they've got disaster fatigue.“ (ABC News)
– Robert Novak claims that Hansen in 1988 over-predicted global warming by 400% (a story originated by Pat Michaels and subsequently propagated by Michael Crichton)
• Fred Singer
Hansen et al 2005 JGR
Radiative Forcing
http://www.giss.nasa.gov/cgi-bin/co2hansen.cgi
2x CO2 and ground Temperature
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