Thinking About Climate Change
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Transcript of Thinking About Climate Change
Climate Systems Analysis Group
Thinking About Climate Change
Climate Systems Analysis Group
A metaphor for
understandingclimate
information
The cahllaenge of birdgnig the sceicne-soictey
dvidie
Learning to read
Climate Systems Analysis Group
Elements to using / interpreting climate change information
Seeing the big picture
Navigating past the deceptions
Understanding the limitations
Knowing the sources
Recognizing the evidence
Integrating past, present, and future – the nugget everyone wants
Managing uncertainty
Revisiting it all again
Climate Systems Analysis Group
Implied: “I need information on Climate Change”Requires: “Integrating multiple lines of evidence”
What is climate information?
What are the components of a climate information package?
What are the limitations on achieving this?
User skill / competency is an inherent component of any solution!
Nuance and Naiveté : Two sides of the coinNuance: at the scale of decision making, there are few one-liners!
Naiveté: the temptation to over interpret
The solution lies in an evolving understanding
Understanding Climate Change
Climate Systems Analysis Group
Adapting to “climate change” … means adapting to what?
Pick as role as a stakeholder seeking to accommodate climate change
What has already changed?
Is that any different from variability?What is the future?
When is the future?How do you know that?
Where do you get your information?Do you “believe” it?
How do you know how good it is?Would you spend your own money based on this information?
At the root of the issue: Do you know threshold vulnerability?
Climate Systems Analysis Group
Information source
(AO)GCMs – CMIP3
Downscaling – RCMs/SD
Process changes
Historical changes
Each source has different:
- attributes of signal and noise- limitations on interpretation- degrees of uncertainty- methodologies of evaluation
User communities
Research scientists
Policy / mitigation
Vulnerability / Impacts
Adaptation
Each community has different:
- definitions / terminology- priorities of need- scales of interest- access to information
Cre
atio
nTr
ansf
orm
atio
nIn
terp
reta
tion
What we would like to accomplish …
Climate Systems Analysis Group
Climate information sits within a context: understand the context in order to understand the information
Context is:
- Relative to the stakeholder, not the provider
- Regional in nature, not amenable to generalizations
- Multi-stressor, which can swamp the relevance of climate
- Evolving, not static in time
Context is critical
Climate Systems Analysis Group
Context is criticalClimate information is unlike an
engineering problem, not a matter of “turning the crank”
Levels of communicable messages:
- Possibility of information (yes / no)- Direction of change (+/-)- Attributes of change (derivatives)- Magnitudes of change (incl thresholds)- Contextual support information (issues of
uncertainty / combinations / etc)- Data – numbers!
Climate Systems Analysis Group
Data
Knowledge
Awar
enes
s Action
Adapted from Zermoglio & Downing
Quadrant of Quandary
Dangerous?Questionable foundationsPossibility of mal-adaptation
Knee-jerk responses
Well-intentioned but misguided
Apathy or Resistance?Political pressuresEconomic constraints
Fear of costs
Saving face
Value ResponseRisk managementReducing vulnerability
Win-win solutions
Short term pain and long term gain
DataClimate models, historical
observations, trends, downscaling, projections, event
frequency, …
InformationMeasures of vulnerability and
risk, threshold exceedence, combinatory impacts, uncertainty
and confidence, regional scale variations, …
KnowledgeAssessing options, understanding
consequences, evaluating responses, informing decision
making, …
A basis for actionPolicy development to balance competing priorities, strategic investments in adaptation and
mitigation, new research avenues, coordination of response frameworks, …
DataClimate models, historical
observations, trends, downscaling, projections,
event frequency, …
InformationMeasures of vulnerability and risk, threshold exceedence,
combinatory impacts, uncertainty and confidence, regional scale variations, …
KnowledgeAssessing options,
understanding consequences, evaluating responses,
informing decision making, …
A basis for actionBalance competing priorities,
strategic investments in adaptation and mitigation,
new research avenues, coordination of response
frameworks, …
Generated by models, analyses, downscaling.... but observations?
Product of data analysis; We are not always sure when we have “information”
Comes with close coupling between science and society, relationship based!
Actions are risky, and takes place within a multi-stressor context
Del
iver
ed
by s
cien
ceN
eede
d by
soc
iety
MINDTHEGAP
Climate Systems Analysis Group
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
Climate Systems Analysis Group
Climate Systems Analysis Group
Easy access data does not equate to actionable information
Climate Systems Analysis Group
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)
Climate Systems Analysis Group
Moving along this chain means many sources of uncertainty
Climate Systems Analysis Group
Moving along this chain means many sources of uncertainty
Climate Systems Analysis Group
What does the future look like?
Climate Systems Analysis Group
Know your context
Dangerous information? Could you recognize it?
Climate Systems Analysis Group
Climate Systems Analysis Group
Climate Systems Analysis Group
Climate Systems Analysis Group
Climate Systems Analysis Group
Climate Systems Analysis Group
Many dependancies in adaptation decision making process
Articulation of relevant thresholds
Understanding natural
variability
Effective communication
between knowledge
provider and user
Tailored information
products
Quantified uncertainty
Iterative and sustained
re-examination
Synergy between process change and
local change
Accommodation of feedbacks and
tipping points
Assessment of error
Balancing multi-stressor
factors
Etc …
Climate Systems Analysis Group
Key challenge: enabling users to develop a robust message about change for supporting adaptation
IPCC AR4 Ch 11
Winter School, Cape Town 2009, Using climate information for adaptation and policy development
Provision of regional tailored climate change data/information online and through stakeholder engagement
A 3-way responsibility:1. Being an honest broker2. Building users capacity 3. Training a new breed of graduate
Climate Systems Analysis Group
The problem is the information
Credible, Defensible, Actionable?
Changing and
evolving
The weakest link is the regional scenario
Climate Systems Analysis Group
WWF
The confusion: taking scientific statements beyond reasonable interpretation
1 cm
12700km
1. Confidence on large scale messages
2. Application for local sector specific needs
Climate Systems Analysis Group
WWF
Suggested approach to interpreting data (Data to Action)
A: Characterize baseline observational climate as best as possible
- Station data, Gridded data, derivatives
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
E: Clearly understand the limits to available data
Climate Systems Analysis Group
Example of developing a regional message:
Global Climate Models (GCMs)(HadCM3, ECHAM5, ~200km) Regional Climate
Models (RCMs) or statistical downscaling(~25km)
Impact models(~1km)
Forcing: Emission Scenarios Initial Conditions
Downscaling
System process changes
Past changes
Climate Systems Analysis Group
Climate Systems Analysis Group
AOGCM multi-model projected changes in sea level pressure and surface winds
Sea level pressure multi-model median anomaly
Surface wind multi-model median anomaly
Climate Systems Analysis Group
AR4 multi-model median anomaly: statistical downscaled precipitation change(2045-2064)
REGIONAL PROJECTIONS
GCM
mm/month: max change = ~15%
Downscaled
Downscale......
Climate Systems Analysis Group
Assess, distill, conclude, communicate a messageusing multiple lines of evidence
Information source Message Discussion
Historical trends•Core winter wetting dominantly in the mountains•Shoulder season drying
•Marginal indications of a possible wetter summer
The region is spatially inhomogeneous in trend magnitude, although the dominant trends can be seen to greater or lesser degrees across the region
GCM changes in circulation / processes
•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
summer convection in the east
•Poleward shift in mid-latitude flow decreasing frontal intensity
•Increased longshore west coast wind promoting stronger
upwelling, colder coastal waters, and consequent drying on the west coast.
The models are in good agreement on these large scale circulation changes, albeit with a range of differing magnitudes of change. The change further is physically consistent with the anticipated first order response of the climate system.
GCM grid cell changes
•General drying over the region•A weak suggestion of possible summer wetting in the north
east
The models are in strong agreement on the drying message for the region, but it is clear that the spatial detail related to local scale topography is absent.
Local scale downscaled changes
•A general drying in the west with modest wetting to the east, modulated by the topography•Core winter wetting in the important water catchments in
the core winter season•Small decreases in rainfall frequency in the west and small
increases in the east
•Changes in dry spell duration commensurate with the above changes.
The downscaled projected changes across all models are robust in spatial pattern although vary in magnitude, and the projected changes in some regions are too small to be of consequence. Of importance is the drying in regions of non-irrigated agriculture in the west, and while core winter wetting in the key catchments is indicated for the near term, later in the century this reverses. Taken with an increase in temperatures, the indication is for problematic increases in water stress.
Climate Systems Analysis Group
Raw GCM projections: rainfall75th percentile
Median“Best estimate?”
25th percentile
Climate Systems Analysis Group
Downscaled rainfall change75th percentile
Median“Best estimate?”
25th percentile
Climate Systems Analysis Group
Climate Systems Analysis Group
NARCCAP
CLARIS
ENSEMBLES
RCMIP
+ polar regions From Colin Jones
CORDEX: changing the game plan of source informationEffectively a data generator – no analysis and application
Climate Systems Analysis Group
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.
2. For some climate variables and for many regions it is not yet possible to 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.
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 interior.
IN SUMMARY......
Climate Systems Analysis Group
4. Historical precipitation change includes both drying and wetting trends depending on the region, and with significant spatial and sub-annual complexity to the signal - no generalized statement 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.
Climate Systems Analysis Group
weAdapt.org community
Expl
orat
ion
tool
s
Building frameworks to address knowledge gaps, decision support, and risk management, and which is good enough
Climate Information Portals
Climate Systems Analysis Group
A global mood swing: Climate services!
World Climate Conference, Geneva, 2009Comments 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?
Climate Systems Analysis Group
CSAG climate information portal:
Climate Systems Analysis Group
Climate Systems Analysis Group
AFRICA
Climate Systems Analysis Group
Observed station data – Ougadougou station
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Downscaled future – Ougadougou station
Rainfall
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Downscaled future – Ougadougou station
Maximum Temperature
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Downscaled future – Ougadougou station
Maximum Temperature days - Exceedance of thresholds
Climate Systems Analysis Group
Thank you....