Thinking About Climate Change

Thinking About Climate Change A metaphor
for
understanding
climate
Learning to read information
The cahllaenge
of birdgnig the
sceicne-soictey
dvidie
Climate Systems Climate Systems
Analysis Group Analysis Group

Elements to using / interpreting climate change Understanding Climate Change
information Implied: “I need information on Climate Change”
Requires: “Integrating multiple lines of evidence”
Seeing the big picture
What is climate information?
Navigating past the deceptions
Understanding the limitations What are the components of a climate information package?

Knowing the sources What are the limitations on achieving this?
Recognizing the evidence
User skill / competency is an inherent component of any solution!
Integrating past, present, and future –
Nuance and Naiveté : Two sides of the coin
the nugget everyone wants
Nuance: at the scale of decision making, there are few one-liners!
Managing uncertainty Naiveté: the temptation to over interpret

Revisiting it all again The solution lies in an evolving understanding


Adapting to “climate change” … means adapting to what?
What we would like to accomplish …
Pick as role as a stakeholder seeking to accommodate
climate change Information source User communities

Transformation
Interpretation
What has already changed? (AO)GCMs – CMIP3 Research scientists

Creation
Is that any different from variability?
Downscaling – RCMs/SD Policy / mitigation
What is the future?
When is the future?
Process changes Vulnerability / Impacts
How do you know that? Historical changes Adaptation
Where do you get your information?
Do you “believe” it? Each source has different: Each community has different:
How do you know how good it is? - attributes of signal and noise - definitions / terminology
Would you spend your own money based on this information? - limitations on interpretation - priorities of need
- degrees of uncertainty - scales of interest
At the root of the issue:
- methodologies of evaluation - access to information
Do you know threshold vulnerability?


Context is critical Context is critical
Climate information sits within a context: Climate information is unlike an
understand the context in order to engineering problem, not a matter of
understand the information “turning the crank”

Context is: Levels of communicable messages:

- Relative to the stakeholder, not the - Possibility of information (yes / no)
provider
- Direction of change (+/-)
- Regional in nature, not amenable to - Attributes of change (derivatives)
generalizations - Magnitudes of change (incl thresholds)
- Multi-stressor, which can swamp the - Contextual support information (issues of
relevance of climate uncertainty / combinations / etc)
- Data – numbers!
- Evolving, not static in time


Data Knowledge Data
Climate models, historical Climate models, historical Generated by models,
observations, trends, observations, trends, analyses, downscaling.... but

by science
downscaling, projections, event Apathy or Value Response downscaling, projections,

Delivered
frequency, … observations?
event frequency, …
Resistance? Risk management
Political pressures
Information Reducing vulnerability
Measures of vulnerability and Economic constraints Win-win solutions
Information
risk, threshold exceedence, Measures of vulnerability and Product of data analysis; We
combinatory impacts, uncertainty Fear of costs Short term pain and long risk, threshold exceedence,
and confidence, regional scale are not always sure when we
combinatory impacts,

Awareness
Saving face term gain have “information”
variations, …

Action
uncertainty and conﬁdence,
MIND regional scale variations, …
Knowledge THE
Assessing options, understanding
consequences, evaluating Dangerous? GAP Knowledge
responses, informing decision
Comes with close coupling
Questionable foundations Assessing options, between science and society,
making, … understanding consequences,

by society
Possibility of mal-adaptation evaluating responses, relationship based!

Needed
informing decision making, …
A basis for action Knee-jerk responses
Policy development to balance Well-intentioned but misguided
competing priorities, strategic
investments in adaptation and A basis for action Actions are risky, and takes
mitigation, new research Quadrant of Quandary place within a multi-stressor
Balance competing priorities,
avenues, coordination of Adapted from Zermoglio & Downing

response frameworks, … Data strategic investments in context
adaptation and mitigation,
new research avenues,
Climate Systems coordination of response
Analysis Group frameworks, …

Difficulties of IPCC-type information
(including many portals)
a) Un-stated limitations of low resolution
information
b) Hides the range of uncertainty
c) Suggests detail, implies confidence


Easy access data does not equate to actionable information Components of climate information
• Rooted in research: evolving and informing (i.e. long term revisiting)

• Data: historical and future projections (accessibility / availability)

• Translation: scales and parameters of relevance in time and space (tailored to
user needs)

• Envelopes: quantification of uncertainty (identification, characterization)

• Context: regional specificities, local knowledge (local partners)

• Communication: in appropriate language and terminology (education and
formulation)

• Relationship: between providers and users (takes time)

• Limitations: clear articulation (being an honest broker)


Moving along this chain means many sources of uncertainty Moving along this chain means many sources of uncertainty


What does the future Know your context
look like?

Dangerous information? Could you recognize it?




Many dependancies in adaptation decision
making process

Tailored
Articulation information
of relevant products
thresholds Balancing
multi-stressor Quantified
Understanding
natural factors uncertainty
variability
Iterative and
Assessment of
Effective sustained
error
communication re-examination
between
knowledge Accommodation Synergy between
provider and user of feedbacks and process change and
tipping points local change
Etc …


Key challenge: enabling users to develop a robust The problem
message about change for supporting adaptation is the information
Credible,
Defensible,
Provision of
regional A 3-way Actionable?
tailored responsibility:
climate 1. Being an
IPCChonest broker
change data/ AR4 Ch 11
Changing
information 2. Building
users capacity and
online
and through 3. Training a evolving
stakeholder new breed of
engagement graduate

Winter School, Cape Town 2009, Using climate information for adaptation and
policy development The weakest link is the regional scenario

The confusion: taking scientific statements beyond reasonable interpretation Suggested approach to interpreting data (Data to Action)
1 cm A: Characterize baseline observational climate as best as possible
- Station data, Gridded data, derivatives
12700km B: Characterize process change to inform understanding
- Consider circulation change as a means to gain conﬁdence in
location-speciﬁc climate
C: Use as many models as possible
- Ideally, focus on model simulations run under common forcing
D: Downscale where possible
- RCM downscaling and/or statistical downscaling; different
strengths and weaknesses

1. Confidence on large 2. Application for local E: Clearly understand the limits to available data
scale messages sector specific needs
WWF WWF


Example of developing a
regional message:
Past changes
Downscaling
Forcing: Emission Scenarios
Initial Conditions

System process changes
Impact
models
(~1km)
Global Climate
Models (GCMs)
(HadCM3, ECHAM5,
~200km)
Regional Climate
Models (RCMs) or
statistical
downscaling
(~25km)

AOGCM multi-model projected Downscale...... REGIONAL
PROJECTIONS
changes in sea level pressure
and surface winds AR4 multi-model
Downscaled median anomaly:
statistical downscaled
precipitation change
(2045-2064)

GCM

Sea level pressure
multi-model median
anomaly
Surface wind multi-model median anomaly mm/month: max change = ~15%

Assess, distill, conclude, communicate a message Raw GCM projections: rainfall
75th percentile
using multiple lines of evidence
Information source Message Discussion

•Core winter wetting dominantly in the mountains The region is spatially inhomogeneous in trend
Historical trends •Shoulder season drying magnitude, although the dominant trends can be
•Marginal indications of a possible wetter summer seen to greater or lesser degrees across the region

•Increased subsidence due to a stronger mid-latitude high
pressure inducing drying
•Deeper thermal surface trough over the continent
increasing west coast pressure gradient and possibly The models are in good agreement on these large
GCM changes in summer convection in the east scale circulation changes, albeit with a range of Median
circulation / differing magnitudes of change. The change further “Best estimate?”
•Poleward shift in mid-latitude ﬂow decreasing frontal
processes is physically consistent with the anticipated ﬁrst order
intensity
response of the climate system.
•Increased longshore west coast wind promoting stronger
upwelling, colder coastal waters, and consequent drying on
the west coast.

•General drying over the region The models are in strong agreement on the drying
GCM grid cell
•A weak suggestion of possible summer wetting in the north message for the region, but it is clear that the spatial
changes
east detail related to local scale topography is absent.

•A general drying in the west with modest wetting to the
The downscaled projected changes across all models 25th percentile
are robust in spatial pattern although vary in
east, modulated by the topography
magnitude, and the projected changes in some
•Core winter wetting in the important water catchments in
regions are too small to be of consequence. Of
the core winter season
Local scale importance is the drying in regions of non-irrigated
downscaled changes •Small decreases in rainfall frequency in the west and small agriculture in the west, and while core winter wetting
increases in the east in the key catchments is indicated for the near term,
Climate Systems later in the century this reverses. Taken with an Climate Systems
•Changes in dry spell duration commensurate with the above
changes.
Analysis Group increase in temperatures, the indication is for Analysis Group
problematic increases in water stress.

Downscaled rainfall change
75th percentile

Median
“Best estimate?”

25th percentile


CORDEX: changing the game plan of source information
Effectively a data generator – no analysis and application
IN SUMMARY......
1. Climate change cannot be reduced to simple national scale messages without
obscuring important sub-regional difference. At the regional and local scale there
can be substantial complexity that requires a rational assessment of multiple sources of
information in order to arrive at a robust message of change.

ENSEMBLES 2. For some climate variables and for many regions it is not yet possible to
NARCCAP formulate a clear message of future change. This is due largely to when a region is
on the boundary between locations having signs of opposite change, and as such is
highly sensitive to the uncertainty in the spatial positioning of the boundary.
RCMIP

3. Temperatures globally have increased in the historical past, and are projected to
increase into the future throughout the 21st century. Future warming might be
greatest in the interior of the continent and less along the coast. Assuming a moderate
to high growth in greenhouse gas concentrations (SRES A2 scenario), by mid-century
the coast is likely to warm by around 1ºC and the interior around 3ºC. By 2100, under
the same scenario, the warming is likely to be around 3ºC on the coast and 5ºC in the
CLARIS interior.

+ polar regions From Colin Jones

4. Historical precipitation change includes both drying and Climate Information Portals
wetting trends depending on the region, and with significant spatial
and sub-annual complexity to the signal - no generalized statement weAdapt.org community
possible.

5. Future rainfall changes are regionally complex, especially in areas
of strong topographical forcing. The message is complex, and hinges
on the interaction of the increased atmospheric moisture content with
topography and changing vertical temperature lapse rates and
convection. At present different information sources give somewhat
contradictory messages.

Exploration tools
Building frameworks to address
knowledge gaps, decision support,
and risk management, and which
is good enough


A global mood swing: Climate services! CSAG climate information portal:

World Climate Conference, Geneva, 2009
Comments on Climate services:
a) Sources: National? International? Commercial?
WMO? NGO? World Bank, Academic?
Partnerships? External intervention or internal
solution? Mainstreaming – what is “Main”
b) Quality: it is assessed? By who? Against what
reference? Accountability?
c) Complexity: is it scale relevant? Is it sector
specific? Does it recognize contradiction?
d) Sustainability: Here today, gone tomorrow?
Supported through what mechanisms?
e) Revisions and updates: Does the message change?
How is that accommodated?
f) Awareness: Are scientists cognizant of user realities?
Are services coupled to science?


AFRICA


Observed station data – Ougadougou station Downscaled future – Ougadougou station

Rainfall


Downscaled future – Ougadougou station Downscaled future – Ougadougou station

Maximum Temperature Maximum Temperature days - Exceedance of thresholds


Thank
you....

Climate Systems
Analysis Group

Thinking About Climate Change

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