Thinking About Climate Change

Climate Systems Analysis Group

Thinking About Climate Change


A metaphor for

understandingclimate

information

The cahllaenge of birdgnig the sceicne-soictey

dvidie

Learning to read


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


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


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?


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

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What we would like to accomplish …


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


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!


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

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MINDTHEGAP


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 look like?


Know your context

Dangerous information? Could you recognize it?







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 …


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


The problem is the information

Credible, Defensible, Actionable?

Changing and

evolving

The weakest link is the regional scenario


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


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


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



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


AR4 multi-model median anomaly: statistical downscaled precipitation change(2045-2064)

REGIONAL PROJECTIONS

GCM

mm/month: max change = ~15%

Downscaled

Downscale......


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.


Raw GCM projections: rainfall75th percentile

Median“Best estimate?”

25th percentile


Downscaled rainfall change75th percentile

Median“Best estimate?”

25th percentile



NARCCAP

CLARIS

ENSEMBLES

RCMIP

+ polar regions From Colin Jones

CORDEX: changing the game plan of source informationEffectively a data generator – no analysis and application


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......


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.


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


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?


CSAG climate information portal:



AFRICA


Observed station data – Ougadougou station


Downscaled future – Ougadougou station

Rainfall



Maximum Temperature



Maximum Temperature days - Exceedance of thresholds


Thank you....

Education

Thinking About Climate Change