Thinking About Climate Change


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CCAFS workshop titled "Using Climate Scenarios and Analogues for Designing Adaptation Strategies in Agriculture," 19-23 September in Kathmandu, Nepal.

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Thinking About Climate Change

  1. 1. 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 GroupElements 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 Climate Systems Climate Systems Analysis Group Analysis Group
  2. 2. 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 / terminologyWould 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? Climate Systems Climate Systems Analysis Group Analysis Group 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 Climate Systems Climate Systems Analysis Group Analysis Group
  3. 3. Data Knowledge Data Climate models, historical Climate models, historical Generated by models, observations, trends, observations, trends, analyses, downscaling.... but by sciencedownscaling, 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; Wecombinatory 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 THEAssessing 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 Climate Systems Climate Systems Analysis Group Analysis Group
  4. 4. 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) Climate Systems Climate Systems Analysis Group Analysis GroupMoving along this chain means many sources of uncertainty Moving along this chain means many sources of uncertainty Climate Systems Climate Systems Analysis Group Analysis Group
  5. 5. What does the future Know your contextlook like? Dangerous information? Could you recognize it? Climate Systems Climate Systems Analysis Group Analysis Group Climate Systems Climate Systems Analysis Group Analysis Group
  6. 6. Climate Systems Climate SystemsAnalysis Group Analysis Group 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 …Climate Systems Climate SystemsAnalysis Group Analysis Group
  7. 7. Key challenge: enabling users to develop a robust The problem message about change for supporting adaptation is the information Credible, Defensible,Provision ofregional A 3-way Actionable?tailored responsibility:climate 1. Being an IPCChonest brokerchange data/ AR4 Ch 11 Changinginformation 2. Building users capacity andonlineand through 3. Training a evolvingstakeholder new breed ofengagement graduate Winter School, Cape Town 2009, Using climate information for adaptation and policy development The weakest link is the regional scenario Climate Systems Climate Systems Analysis Group Analysis GroupThe 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 Climate Systems Climate Systems Analysis Group Analysis Group
  8. 8. Example of developing aregional message: Past changesDownscalingForcing: Emission ScenariosInitial Conditions System process changes Impact models (~1km) Global Climate Models (GCMs) (HadCM3, ECHAM5, ~200km) Regional Climate Models (RCMs) or statistical downscaling (~25km) Climate Systems Climate Systems Analysis Group Analysis GroupAOGCM multi-model projected Downscale...... REGIONAL PROJECTIONSchanges in sea level pressureand surface winds AR4 multi-model Downscaled median anomaly: statistical downscaled precipitation change (2045-2064) GCM Sea level pressure multi-model median anomalySurface wind multi-model median anomaly mm/month: max change = ~15% Climate Systems Climate Systems Analysis Group Analysis Group
  9. 9. 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 trendHistorical 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 largeGCM changes in summer convection in the east scale circulation changes, albeit with a range of Mediancirculation / differing magnitudes of change. The change further “Best estimate?” •Poleward shift in mid-latitude flow decreasing frontalprocesses 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 dryingGCM grid cell •A weak suggestion of possible summer wetting in the north message for the region, but it is clear that the spatialchanges 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 seasonLocal scale importance is the drying in regions of non-irrigateddownscaled 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 change75th percentileMedian“Best estimate?”25th percentile Climate Systems Climate Systems Analysis Group Analysis Group
  10. 10. 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. Climate Systems Climate Systems Analysis Group Analysis Group+ 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 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 Climate Systems Climate Systems Analysis Group Analysis Group
  11. 11. A global mood swing: Climate services! CSAG climate information portal: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 Climate Systems Analysis Group Analysis Group AFRICA Climate Systems Climate Systems Analysis Group Analysis Group
  12. 12. Observed station data – Ougadougou station Downscaled future – Ougadougou station Rainfall Climate Systems Climate Systems Analysis Group Analysis GroupDownscaled future – Ougadougou station Downscaled future – Ougadougou station Maximum Temperature Maximum Temperature days - Exceedance of thresholds Climate Systems Climate Systems Analysis Group Analysis Group
  13. 13. Thankyou.... Climate Systems Analysis Group
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