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