Stephen H. Schneider*Stephen H. SchneiderMelvin and Joan Lane Professor for Interdisciplinary

Environmental Studies,Environmental Studies,Professor, Department of Biological Sciences

Senior fellow, Woods Institute for the EnvironmentStanford University

Report of the Intergovernmental p gPanel on Climate Change (IPCC)

2008 ESRI International User Conference2008 ESRI International User Conference August 5, 20088:30-9:45amR 32 A/BRoom 32 A/B

*[Website for more info: climatechange.net.]

“It’s TheIt s The PreponderancePreponderance,

Stupid!!!”Stupid!!!”

“It’s TheIt s The PreponderancePreponderance,

Stupid!!!”*Stupid!!!”**With apologies to James Carville

Graphic:http://www.washingtonpost.com/wp-dyn/content/article/2008/03/18/AR2008031802903.html

Thi d NThinner and NewerA cool Arctic winter has brought sea ice back to broad expanses that melted clear during last summer's unusual warmth. However, gthe amount of thick "perennial ice" has declined sharply across the Arctic, and climate experts say that global warming is the cause.

The “Real” Cause of Global Warming

The “Real” Cause of Global Warming

Victims AsVictims As Villains

Is The ScienceIs The Science “Settled”?Settled ?

Is The ScienceIs The Science “Settled”?Settled ?

-Well-established componentsWell established components

-Competing Explanations

-Speculative components

Global Warming is Happening NOW:Global Warming is Happening NOW:

“Warming of the climate system is unequivocalWarming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, g g p ,widespread melting of snow and ice, and rising global mean sea level (see Figure SPM-3). {3.2, 4.2, 5.5}.”

IPCC, Summary for Policymakers, Contribution of Working Group I to the Fourth Assessment Report, g p p

February, 2007

Clear Trend

False Trends!

False Trends!

Observed trend

Natural Causes Only

Observed trend

IPCC: “Very Likely” humans caused most of

recent warming

Natural Causes OnlyNatural + Human Causes

Observed trend

Munich Re:

Wh t d “d ” li t“We need to stop this dangerous

experiment humankind isWhat does “dangerous” climate change really mean?

experiment humankind is conducting on the Earth’s change really mean?g

atmosphere.”

Characterization ofCharacterization of Climate Problem:Climate Problem:

*Potential For Significant Risksg*Deep Uncertainties

*N ti J d t*Normative Judgments*”Optimal” Solutions Tenuousp

****************************”Ri k/M t F k”Risk/Management Framework

Risk Management Requires PDFsPDFs

Climate UncertaintyClimate UncertaintyClimate UncertaintyClimate Uncertainty

Climate UncertaintyClimate UncertaintyClimate UncertaintyClimate Uncertainty

0.04

0.02

0.03D

ensi

ty

0

0.01

D

0 1 2 3 4 5

Temperature Change above 2000 (oC)

Climate UncertaintyClimate UncertaintyClimate UncertaintyClimate Uncertainty

0.04 Temperature

0.02

0.03D

ensi

ty

pprobability density function for 2100 based on PDF for li t iti it

0

0.01

D climate sensitivity

0 1 2 3 4 5

Temperature Change above 2000 (oC)

Most sensible decision paradigm?: Risk-management.

The great “greenhouse g ggamble”…

<1°C (4.1%; 1 in 24 odds)

1 t 1 5°C (11 4% 1 i 9 dd )1 to 1.5°C (11.4%; 1 in 9 odds)

1.5 to 2°C (20.6%; 1 in 5 odds)

2 to 2.5°C (22.5%; 1 in 4 odds)

2 5 t 3°C (16 8% 1 i 6 dd )2.5 to 3°C (16.8%; 1 in 6 odds)

3 to 4°C (16.2%; 1 in 6 odds)

4 to 5°C (4.6%; 1 in 22 odds)

>5°C (3.8%; 1 in 26 odds)

Source: MIT Joint Program on the Science and Policy of Climate Change

APPENDIX 2OUTLINE FOR THE IPCC WORKING GROUP II CONTRIBUTION TO

The “PAO”:

THE FOURTH ASSESSMENT REPORTCLIMATE CHANGE 2007: IMPACTS, ADAPTATION AND VULNERABILITY

Agreed by Plenary XXI, Vienna, 2004

19. Assessing Key Vulnerabilities and the Risk from Climate Change• Methods and concepts: issues relating to Article 2 of the UNFCCC; reasons for concern;measuring damage; identifying key impacts and vulnerabilities, and their risk of occurrence• Approaches to determining levels of climate change for key impacts• Assessing key global risks• Assessing key risks for regions and sectors

Assessment of response strategies to avoid occurrence: stabilisation• Assessment of response strategies to avoid occurrence: stabilisation scenarios;mitigation/adaptation strategies; avoiding irreversibilities; role of sustainable development;sustainable development;treatment of uncertainty• Uncertainties, unknowns, priorities for research

WHAT ARE THE FUTUREWHAT ARE THE FUTURE IMPLICATIONS OF POPULATION,IMPLICATIONS OF POPULATION,

AFFFLUENCE AND TECHNOLOGY GROWTHTECHNOLOGY GROWTH

PROJECTIONS?PROJECTIONS? *******************************

HOW CAN THE FUTURE BE SCIENTIFICALLY ANALYSED?SCIENTIFICALLY ANALYSED?

B t i it t b l t i ht b tBut is it not absolute weight, but DIFFERENTIAL weight that affects two car crash consequences—sotwo car crash consequences so ALL cars on a diet would improve safety [and sustainability] by y [ y] y“leveling the playing field”. Should ability to pay allow one the right to

d th ? N t i ilendanger others? Not primarily an economics, but ethics, question!

‘The words of the prophet are p pwritten on the…?’

We can Choose our Emissions Future(Intergovernmental Panel on Climate Change Emission Scenarios)

25

30

35

C)

AifiHigher

Emissions

15

20

25

ssion

s (Gt

C

A2 Medium-High Emissions

A1FI

0

5

10

CO2 E

mis

Historic B1 Lower Emissions

1800 1850 1900 1950 2000 2050

Year

Just fossil fuel emissions shown in graphic.

We can Choose our Emissions Future(Intergovernmental Panel on Climate Change Emission Scenarios)

CO2 t i li t 2100 th

25

30

35

C)

AifiHigher

Emissions

CO2 tripling at 2100, then more

A1FI

15

20

25

ssion

s (Gt

C

A2 Medium-High Emissions

CO2 doubling,

then stabilized

A1FI

0

5

10

CO2 E

mis

Historic B1 Lower Emissions

1800 1850 1900 1950 2000 2050

Year

Just fossil fuel emissions shown in graphic.

Climate System Uncertainty

Calculating The Range of Warming

Emissions ScenarioScenario Uncertainty

Source: IPCC, WG 1, AR4, 2007

6.4 C

Warming Very Likely—But How Much?: Wide Range

1.1 C1.1 C

Source: IPCC, WG 1, AR4, 2007

Good or Good or bad impact??

“Very High Confidence”* Global Warming Impacts

• North American Impacts Projected

Impacts

North American Impacts Projected–Water Impacts: “Warming in western

mountains is projected to cause decreasedmountains is projected to cause decreased snowpack, more winter flooding, and reduced summer flows, exacerbating competition for over-allocated water resources.”

IPCC, Summary for Policymakers, Working Group II Contribution to the Fourth Assessment Report, April, 2007

*Very High Confidence in the IPCC AR4 is defined as*Very High Confidence in the IPCC AR4 is defined as greater than 9 out of ten chance of occurrence

“Very High Confidence” Global Warming ImpactsImpacts

• North American Impacts Projected (cont’d)– Fire & Pest Impacts: “Disturbances from

pests, diseases, and fire are projected to have increasing impacts on forests, with an extended period of high fire risk and large i i b d “increases in area burned. “

IPCC Summary for Policymakers Working Group IIIPCC, Summary for Policymakers, Working Group II Contribution to the Fourth Assessment Report, April, 2007

Wildfires Frequency increased f f ld i l 30 four fold in last 30 years.

Western US area burned

Source: Westerling et al. 2006

“Very High Confidence” Global Warming ImpactsImpacts

• North American Impacts Projected (cont’d)Heat Wave/Public Health Impacts: "Cities thatHeat Wave/Public Health Impacts: Cities that currently experience heat waves are expected to be further challenged by an increased number, g y ,intensity and duration of heat waves during the course of the century, with potential for adverse

IPCC S f P li k W ki G II

health impacts. The growing number of the elderly population is most at risk.”

IPCC, Summary for Policymakers, Working Group II Contribution to the Fourth Assessment Report, April, 2007

Extraordinary & Compelling Conditions

Hotter Days Lead to More Smog

0.25

0.30

(ppm

)

0.15

0.20

mum

Ozo

ne

South Coast Air BasinOzone Levels

0.05

0.10

Dai

ly M

axim Ozone Levels

(1996-1999)

0.0040 60 80 100 120

M M i T t (oF)

D

Mean Maximum Temperature (oF)Our Changing Climate: Assessing the Risks to California (2006),

www.climatechange.ca.gov. Source: Air Resources Board, 2000

Increase in WildfiresPollution in Plumes

LOWER WARMING RANGE60NIM

UM

ER Y

EAR

LOWER WARMING RANGEMEDIUM WARMING RANGE

ECTE

D M

IFI

RES

PE

30

GE

IN E

XPE

OF

LAR

GE

2035-2064 2070-20990

% C

HA

NG

UM

BER

O

Source of data : Westerling and Bryant, “Climate change and wildfire in and around California: Fire modeling and loss modeling” (2006),

www.climatechange.ca.gov

2035-2064 2070-2099% N

Extraordinary & Compelling Conditions

More Smog Likely: Section 209(b) clearly covers

100Lower Warming RangeMid Warming Range

g y ( ) ythis extraordinary and compelling condition

50

75% Increase

Day C d i

Mid Warming Range

25

50Conducive to Ozone

formation

0Los Angeles San Joaquin ValleyLos Angeles San Joaquin Valley

Data from GFDL B1 and A2 runs. SOURCE: Kleeman et al. 2006

Our Changing Climate: Assessing the Risks to California (2006), www.climatechange.ca.gov

“Very High Confidence” Global Warming Impacts

• North American Impacts Projected (cont’d)– Coastal Impacts : “Coastal communities and

h bit t ill b i i l t d b li thabitats will be increasingly stressed by climate change impacts interacting with development and pollution. Population growth and the rising

l f i f t t i t l ivalue of infrastructure in coastal areas increase vulnerability to climate variability and future climate change, with losses projected to g , p jincrease if the intensity of tropical storms increases. Current adaptation is uneven and readiness for increased exposure is low.” ead ess o c eased e posu e s o

IPCC, Summary for Policymakers, Working Group II Contribution to the Fourth Assessment Report, April, 2007

Rising TemperatureEnd of Century IncreasesEnd of Century Increases

(Summer Average)°F

LOWER EMISSIONS HIGHER EMISSIONS18.016.214.4

�

12.610.89.07.25.43.6

--$--$summer summer1.80.0

- 1.8- 3.6

Notes: HadCM3 model results for 2070-2099 vs. 1961-1990. Higher emissions = A1fi; lower emissions = B1 scenarios from IPCC Third Assessment Report. Downscaled results from E. Maurer (http://www.engr.scu.edu/~emaurer/index.shtml).

Rising Temperatureg pEMISSIONS MATTER!

°F

LOWER EMISSIONS HIGHER EMISSIONS18.016.214.4

�

12.610.89.07.25.43.6

--$--$summer summer1.80.0

- 1.8- 3.6

Notes: HadCM3 model results for 2070-2099 vs. 1961-1990. Higher emissions = A1fi; lower emissions = B1 scenarios from IPCC Third Assessment Report. Downscaled results from E. Maurer (http://www.engr.scu.edu/~emaurer/index.shtml).

Any US Robust Conclusions?

Yes (unfortunately) in California

Winter Summer

• and 1,100 heat related deaths per year

Source: Climate Change Health Impacts in Australia, ACF & AMA

Temperature changes: 2070Temperature changes: 2070X <=3.92

95%X <=1.44

5%0.12

0 08

0.1

0.06

0.08

Prob

abili

ty

0.02

0.04

P

00 1 2 3 4 5 6

Temperature change (oC)Temperature change ( C)

Rainfall changes: 2070Rainfall changes: 2070X <=0.07

95%X <=-26.07

5%0.3

0 2

0.25

0.15

0.2

Pro

babi

lity

0.05

0.1

0-60 -40 -20 0 20

Rainfall change (%)

• and 8,000 - 15,000 heat related deaths per year

Source: Climate Change Health Impacts in Australia, ACF & AMA

• and 8,000 - 15,000 heat related deaths per year

Source: Climate Change Health Impacts in Australia, ACF & AMA

• and 4,000 - 8,000 heat related deaths per year

Source: Climate Change Health Impacts in Australia, ACF & AMA

PARADIGMATIC DILEMMA (All language is from IPCC SPMs):

Risk management framework emerges as a useful framework to address keyuseful framework to address key vulnerabilities.

“ ”“versus”

However, the assignment of probabilities to specific key impacts is often very difficultspecific key impacts is often very difficult due to the large uncertainties involved.

PARADIGMATIC DILEMMA (All language is from IPCC SPMs):

Risk management framework emerges as a useful framework to address keyuseful framework to address key vulnerabilities.

“ ”“versus”

However, the assignment of probabilities to specific key impacts is often very difficultspecific key impacts is often very difficult due to the large uncertainties involved.

Governor ofGovernor of California:California: 80% reduction in80% reduction in

i i b 2050emissions by 2050

*The “Two percent Solution”

*But overshoots are inevitable, so do as much as possible as fast and as fairly as can be reasonably y yachieved.

*The “Two percent Solution”

*But overshoots are inevitable, so do as much as possible as fast and as fairly as can be reasonably y yachieved.

McKinsey-NRDC “Supply Curves”Supply Curves

Still big uncertaintiesg

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Policy Sequence:Policy Sequence:1-Adaptation to change already in the pipeline2-Performance standards2 Performance standards3-Public private partnerships (incentives to innovation)4-Shadow price on carbon (polluter4-Shadow price on carbon (polluter pays--with equity side payments)5-Geoengineering

Questions??

Comments???