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The Science of Climate
Change
Where We Are: The Consensus,
the Controversy, and the Climate
Robert Wyman
Partner, Latham & Watkins LLP
The IPCC

The Intergovernmental Panel on Climate
Change





Established in 1988 to assess scientific basis of
climate change
Open to all members of UN and WMO
Intended to be policy-neutral
Most work performed by more than 1000 volunteer
scientists
Earned share of Nobel Peace Prize in 2007
Current Structure of IPCC

IPCC Panel comprised of
government delegations;
sets agenda

IPCC Bureau (31
members) provides
guidance to Lead Authors

Since 2001, most work of
IPCC performed by 3
Working Groups
How Climate Assessments are
Made:

Assessments generated every 4-7 years
 Last report in 2007; next one expected in 2014

Step 1: IPCC evaluates lessons from previous assessments

Step 2: Panel elects IPCC Chair, the Co-Chairs of Working
Groups, and the rest of Bureau

Step 3: Working Group Co-Chairs select the Coordinating Lead
Authors (CLA’s) and Lead Authors (LA’s)
 CLA’s coordinate major sections of Working Group report
 LA’s ensure work is based on best evidence and is brought
together in a consistent manner
How Climate Assessments are
Made:

Step 4: CLA’s and LA’s receive input from
Contributing Authors (CA’s)


CA’s prepare technical information for assimilation
Step 5: Reviews of Reports

2 formal reviews and one or more informal reviews
 Informal reviews provided by small number of scientists
(usually other authors)
 Experts then review first complete draft
 LA’s respond to comments, prepare second draft


Review Editors ensure comments and controversial issues are
handled appropriately
Second Draft reviewed by same experts, government
representatives
How Climate Assessments are
Made:

Step 6: Final Working Group Report
 Four layers


main chapter texts, executive summaries, technical summaries &
“Summary for Policymakers”
Summary is approved, line by line, in a session chaired by WG CoChairs and attended by government representatives
 After approval, entire report forwarded to Panel for acceptance
 Summaries for policymakers are most important because they
have highest visibility


Step 7: The Synthesis Report
 Combines findings of all working groups
 Only two layers


Main report (divided into 6 topics) and a Summary for Policymakers
Summary is approved line by line
Inherent Obstacles with Study
of Climate

Available scientific information:





Is extensive, multinational, and multidisciplinary
Extends across multiple spatial and temporal scales
Subject to different interpretations and a wide range of
uncertainties
Climate change is politically charged due to
economic consequences
Traditional linear science-for-policy model will not
work

Expert Judgment essential
Additional Difficulties for WGII and WGIII

WG I – physical climate analysis based on:




Natural science disciplines
Peer-reviewed literature
Global models and observations
WG II and WG III

Because focused on the effects of and the
responses to climate change, analyses based on:



Social science disciplines
Fewer experts
Non-peer reviewed literature (gray literature)
The conclusions of IPCC drive policy
decisions at home and abroad

Ex: EPA’s recent “endangerment finding” that
greenhouse gases are a danger to public health



Finding based on IPCC conclusions
Endangerment finding sets up regulation of
greenhouse gases through the Clean Air Act
Ex: IPCC’s work provided scientific basis for
proposed “cap and trade” legislation that recently
passed the U.S. House of Representatives
Key Findings of IPCC

Second Assessment Report (1995)

“Climate has changed over the past century”



Global mean surface air temperature has increased
between 0.3 and 0.6 degrees C since late 19th century
Global sea level has risen between 10 and 25 cm over
the past 100 years; rise may be related to increase in
global mean temperature
“ The balance of evidence suggests a
discernible human influence on global climate”
Key Findings of IPCC

Third Assessment Report (2001)



Temperature increase in 20th century “likely” to have been the largest of any
century in past 100 years
“Very likely” that the 1990’s was the warmest decade on record (since 1861) and
1998 was the warmest year
New, stronger evidence that most warming observed over last 50 years
attributable to human activities
Key Findings of IPCC

Fourth Assessment Report (AR4) (2007)

Most warming of past 50 years is “very likely”
(odds 9 out of 10) due to human increases in
greenhouse gases

Consensus: “Warming of the climate system is
unequivocal, as is now evident from
observations of increases in global average air
and ocean temperatures, widespread melting of
snow and ice, and rising global average sea
level”
Other Scientific Findings:

Observed change is faster than expected

Newer studies foresee greater change
impacts

Climate change impacts are already affecting
the U.S.
Faster Change: Large Ice Sheets
IPCC Third Assessment Report (2001)
The Antarctic ice sheet as a whole is likely to increase in
mass during the 21st century.
IPCC Fourth Assessment Report (2007)
…the ice sheets in Greenland and Antarctica have very likely
been contributing to sea level rise over 1993 to 2003.
Shepherd & Wingham (2007)
…data show that Antarctica and Greenland are each losing
mass overall.
14
Greater Sea Level Rise
2.6 ft
“best estimate”
15
Pew Center Science Brief 2
GCRP Report
Key Findings
This report is“…by far the most up to date,
• Global warming is
comprehensive,
and authoritative assessment of
unequivocal
and primarily
climate change impacts on the United States. It is
human-induced
focused … on what is already happening and …
• Climate changes are
what
is
expected
to
happen
going
forward
under
underway in the U.S. and
both low-emission
scenarios where [we] elect to
projected
to grow
take serious measures to reduce the pace and
• Widespread climatemagnitude of climate change, and under higherrelated impacts are
emission
scenarios
in which we don’t.”
occurring
now and
are
expected to increase
John Holdren, President’s Science Advisor
GCRP Press Conference, June 2009
16
NORTHWEST
•Declining snowpack
affects water, hydro
•Loss of coldwater fish GREAT PLAINS
•Increased wildfires
•Ag stresses from water
availability, higher temps
•Alterations of habitat
SOUTHWEST
•Scarce water supplies
•Incr. drought, wildfires,
invasive species
ALASKA
•Hotter, drier summers
•Loss of sea ice
•Thawing permafrost
damages infrastructure
NORTHEAST
•More extreme heat
•Declining air quality
•Increase in heavy rain
•Loss of sugar maple
MIDWEST
•More heat waves
•Ag stresses from floods, droughts, pests
SOUTHEAST
•SLR and incr. hurricane intensity
•Droughts, reduced water avail.
•Heat stress, extreme weather
17
Extreme Heat
US GCRP Climate Impacts Report
18
Climate on the Move
US GCRP Climate Impacts Report
19
Climate on the Move
Projected Heat Related Deaths in Chicago
US GCRP Climate Impacts Report
20
What a rise in sea
level of 3.3 feet
means for the MidAtlantic region
21
The Bottom Line . . .
“I think that much of the foot dragging in
addressing climate change is a reflection of the
perception that climate change is way down the
road … and that it only affects remote parts of
the planet. And this report demonstrates … that
climate change is happening now and it's
happening in our own backyards and it affects
the kinds of things people care about.”
Dr. Jane Lubchenco, NOAA Administrator
GCRP Press Conference, June 2009
22
Or is it . . .

The Recent Controversies



East Anglia CRU e-mail scandal
IPCC admits errors in the 2007 assessment
Independent Reviews




U.K. Investigation of CRU e-mails (July 2010)
U.S. Senate Committee on Environment and Public Works:
Minority Staff Report on CRU e-mails (Feb 2010)
InterAcademy Council (IPCC review) (August 2010)
Netherlands Environmental Assessment Agency (IPCC
review) (July 2010)
The East Anglia Controversy

The Climate Research Unit, University of
East Anglia



CRU is a small research unit which, over the last
30 years, has played an important role in climate
science
In November 2009, approximately 1000 e-mails
from CRU scientists were hacked
E-mails raise question of scientists’ integrity
Why is the important?


A number of CRU
scientists played
important roles in
generating IPCC
In case you are falling asleep,
reports
This chart is a joke . . .
Important to
remember that theThis is not CRU’s scientific method …
CRU is not the
But some opponents claim it is
IPCC; it is just a
small unit that
contributes to
IPCC findings
Roles of CRU Scientists in
IPCC Reports
Author
Number of e-mails
Role
Philip Jones
174
Director, CRU, UEA and
Coordinating Lead Author
IPCC 4th Assessment Report
Michael Mann
140
Director, Earth System Science Centre,
Pennsylvania State University (from 2005), and
Lead Author IPCC 3rd Assessment Report
Keith Briffa
117
Professor, CRU, UEA and
Lead Author IPCC 4th Assessment Report
Jonathan Overpeck
90
Institute Director, University of Arizona and
Coordinating Lead Author IPCC 4th AR
Tim Osborn
59
Academic Fellow, CRU, UEA and
Contributing Author IPCC 4th AR
Ben Santer
51
Researcher, Lawrence Livermore National Lab, US and
Contributing Author IPCC 4th AR
Tom Wigley
35
Former Director of CRU
Scientist, University Corporation for Atmospheric
Research
Contributing Author IPCC 4th AR
A sampling of the CRU allegations

Is the famous Hockey Stick chart a product of cooked science?

Hockey Stick – charts temperatures over last 1000 years
Hockey Stick Controversy

The “Divergence Problem”



No thermometers pre-1850
So, use a proxy. For example, use tree ring
density to chart temperatures
Hockey Stick Chart based on four such proxies


One created by Briffa (tree ring), one by Jones, and
two by Mann
Next chart shows all reconstructions – from IPCC 3rd
AR (2001)
Hockey Stick Controversy
Where did the
green line go?
Hockey Stick Controversy


The green line declines around 1960
Chart below shows original unpublished data
Tree ring model
shows a temperature
decline after 1960 – Is
the earth
unequivocally
warming?
Also note the black lines –
they represent measured
temperature. They begin
around 1850
Red proxy
line also
declines a bit
… then goes
back up
Hockey Stick Controversy
What to Do?
Green line decline sends Briffa, Jones, and
Mann into a frenzy
From: Keith Briffa [CRU]

To: Chris Folland [UK Met Office]; Phil Jones [CRU]; Michael E. Mann [University of Virginia]
Cc: Tom Karl [National Climatic Data Center – NOAA]
September 22, 1999
Scientists are concerned that the green line
Subject: RE: IPCC revisions . . . I know there is pressure to present a nice tidy story as
decline
will contradict
ideayears
of or more in the proxy data’
regards
'apparent unprecedented
warming inthe
a thousand
but in reality the situation is not quite so simple. We don't have a lot of proxies that come
right upunprecedented
to date and those that do (at warming
least a significant number of tree proxies )

some unexpected changes in response that do not match the recent warming. . . .

Briffa responds in an e-mail
“Hide the Decline”
From: Phil Jones [CRU]
To: Ray Bradley [University of Massachusetts, Amherst]; Michael E. Mann
[University of Virginia]; Malcolm Hughes [University of Arizona]
Cc: Keith Briffa [CRU]; Tom Osborn [CRU]52
November 16, 1999
Subject: Diagram for WMO [World Meteorological Organization] Statement
Dear Ray, Mike and Malcolm,
Once Tim's got a diagram here we'll send that either later today or first thing tomorrow.
I’ve just completed Mike’s Nature trick of adding in the real temps to each series
for the last 20 years (ie from 1981 onwards) and from 1961 for Keith’s to hide the
decline. Mike's series got the annual land and marine values while the other two got
April-Sept for NH [Northern Hemisphere] land N of 20N. The latter two are real for 1999,
while the estimate for 1999 for NH combined is +0.44C wrt 61-90. The Global estimate
for 1999 with data through
Oct is +0.35C cf. 0.57 for 1998. Thanks for the comments, Ray.
Cheers
Phil
“Hide the Decline”


Cut off tree ring data where it begins downward trend (around 1961)
And merge line with recorded temperatures
“Any scientist ought to
know that you just can’t
mix and match proxy
and actual data.
They’re apples and
oranges.”
-Phillip Scott; emeritus professor of
biogeography at London’s School
of Oriental and African Studies
Decline Hidden
Fallout

Remember, the “hide the decline” trick was
performed on the 2001 IPCC report, not the
2007 report

UK assesses the controversy


Determines that similar information concerning tree
ring proxies presented in 4th report was not misleading
But the information provided in the “iconic” graph of
the 3rd report was misleading.


Chart did not adequately explain methods
Overall, this error does not “undermine the
conclusions” of the IPCC—that climate change is
happening and is probably caused by humans
Other criticisms

In addition to “hide the decline,” UK
assessors determined that the e-mails
revealed that:

Scientists demonstrated a “consistent pattern of
failing to display the proper degree of openness”

CRU researchers’ responses for requests of
information were “unhelpful and defensive”
Other Views

The Senate Minority Staff on the EPW
Committee was more harsh in its assessment



Determined the scientists tried to undermine peer
review
Were actively pursuing an agenda
Does this mean climate change is a hoax?
The Debate
Next Controversy:
IPCC Admits Errors on 4th AR


Reported errors are largely unrelated to the
CRU e-mail controversy
Jan 20, 2010 announces error:


AR 4 asserted: “Glaciers in the Himalayas are
receding faster than in any part of the world . . .
the likelihood of them disappearing by the year
2035 and perhaps sooner is very high.”
IPCC official admits error. “It is so wrong it is not
even worth discussing”
Another Error



In February 2010 IPCC admits another error
in their 4th AR
Report asserted that 55% of Netherlands was
currently below sea level. Report traced this
figure to global warming.
IPCC later correct assertion:


Only 26% of the country was below sea level,
55% is at risk of flooding
Errors Prompt Independent
Review of IPCC Procedures


Review by Netherlands Environmental
Assessment Agency
Findings:

Only one other major error in AR 4


Report projected a 50 to 60% decrease in productivity
of anchovy fisheries on African West Coast
The report should have read that there appeared to be
a 50 to 60% decrease in extreme wind and seawater
turbulence, which may lead to some unquantified
negative effects on anchovy population
Other Dutch Findings

Summary conclusions presented in the “Summaries
for Policymakers” were well founded and did not
contain significant errors

But some minor inaccuracies in summary
conclusions, and

Seven of the 32 summary conclusions on the
regional impacts of global warming contain
information that could not be sufficiently traced to
the underlying source within the Working Group II
report
More findings


In the “Summaries for Policymakers,” the WGII
assessments single out negative effects of warming
This “risk oriented approach” of focusing on the
negative not sufficiently disclosed in the report



Report also highlights risks at upper end of uncertainty range
Does not put information in context
As a result, policymakers often are not aware of
potential benefits of warming


Benefits often buried in technical layers of report
Ex: Synthesis Report contains discussion on crop yields
that are likely to be reduced in Africa, but does not mention
crop yields that may increase due to global warming
Report Recommendations and
Conclusions


Dutch findings do not contradict main conclusion of IPCC
on impact, adaption, and vulnerability related to climate
change (WG II)
Findings do not contradict IPCC conclusion that:



Global warming is unequivocal and
“Very Likely” caused by human activity
But room for improvement – recommendations:




Provide public website for submission of errors found in
published reports
Provide stronger underpinnings for generalizations
Strengthen review process
More disclosure of methodology
InterAcademy Council


Multinational organization of science academies
Similar findings and recommendations:


Assessment reports successful overall
But IPCC must structurally reform
 Needs more day-to-day leadership (Executive Director
needed)
 Needs to ensure controversies adequately addressed
 More targeted review process to focus on specific problems
 Quantify uncertainty where possible (likelihood scale should
be used where appropriate)
 Authors need to indicate scientific basis for assigning a
probability that an event will occur
 Greater emphasis on transparency
Most Recent Developments

2010 on track to be a record hot year
(running neck and neck with 1998, the hottest
year on record)

Recently discovered that the Greenland and
West Antarctic Ice Caps are melting at half
the speed previously predicted
In the end . . .

Climate Change





Is it happening?
Is it caused by man?
Even if it is happening, can we counter it?
Should we counter it, or should we adapt?
You decide
Special Thanks

A number of the slides in this presentation
were created by the Pew Center on Global
Climate Change