Breakout Groups ONE Francis Zwiers Stewart Cohen Bryan Tugwood Rick Lee Ray Desjardins Seong Heon Kim Bill Richards Katja Woth Georges Desrochers FOUR Rob Wilby Dieter Riedel Mark Barton John Charlery Juno Song Kim Logan Paulin Coulibaly Suzan Lapp Tan Danh Nguyen TWO Jean Palutikof Don Lemmen Julia James Elaine Wheaton Bill Taylor Jim Byrne Nicole McKechnie Carrie Holcapek Mohammad Matiur Rahmen FIVE Alain Bourque Clare Goodess Sam Gameda Denise Neilsen André St. Hilaire Gary Lines VTV Nguyen Adam Fenech Bill Girling THREE Hélène Côté Eric Taylor Ben Kangasniemi Vanessa Egginton Abdel Maarouf John Anderson Shusen Wang Jim Helbig SIX Dave Sauchyn Xuebin Zhang Bing Rong Henry Hengeveld Ross Herrington Jiafeng Wang Ge Yu Martin Lacroix Juraj Cunderlik

Extremes Scenarios Workshop: Breakout Group 1 Cohen, Zwiers, McKinnon, Lee, Desjardins, Richards, Kim, Woth, Desrochers, Tugwood

Q1:most important aspects of variability/extremes Frequency, duration, severity, timing of events some elements will have to be derived outside of the GCM (e.g. soil moisture) others can be obtained directly (e.g. freeze- thaw)

Q2: which variables? Soil moisture water: precipitation IDF atmospheric stability: mixed layer depth sea level rise: 6-hour event from RCM

Q3: what should a scenario consist of? Change in risk of a particular event RCM--scenarios of internally consistent multiple variables (e.g. warm-dry spells)

Q6: past climates What is ‘more’ reliance? Can learn about undisturbed conditions can complement instrumental record possible use as temporal analogue (with caveats)

Q7: uncertainty Range of plausible outcomes, so specific language may not be desired (uncertain about use of IPCC terminology--needs further work) for impacts--scenario comes from a known source with unknown probability

Q8: downscaling Yes, impacts researchers want to use this could use either RCM or statistical methods (with appropriate caveats for each)

Q13: national strategy Hard to find another facility like CCIS; goes beyond what UK-LINK does impacts community well served by CCIS; better then what existed before; this reduces gap between GCM output production and its use for impacts/adaptation research

National Workshop on the Development of Scenarios of Climate Variability and Extremes Data and Knowledge Gaps more data available – starting with dew point, radiation major gaps on ocean parameters El Nino / NAO – need Canadian research capacity time scales – focus on relevance to stakeholders (nearer term) paleo needs to be integrated into all aspects of scenario development For I&A work key variables need to be stakeholder defined – need process to have this lead Group 2

National Workshop on the Development of Scenarios of Climate Variability and Extremes Strategy increased collaboration between gov’t departments regional expertise in regional centres driven by impacts and adaptation needs needs to be supported by research program – e.g. uncertainties scenario facility needs to reside within gov’t as need is driven by policy, ensure long term stability model of collocation of gov’t and university researchers RCM output could contribute significantly, need more runs and greater access to data Group 2

National Workshop on the Development of Scenarios of Climate Variability and Extremes Uncertainty critical to communicate but very difficult to do define level needed depends on decisions that are being made uncertainty of when generally less important than if assessment of models – limit access to less reliable model data place emphasis on probability distribution functions Group 2

Group 3 Question 1. a) Need to define extreme for specific sector or location. b) More analysis needed of historical climate extremes and variability. c) More information needed on “event-driven” historical extremes - e.g. hot spells in conjunction with warm low temperatures and high humidity. d) Historical data from different agencies needed to be made available to all agencies and researchers. e) Monitoring network needs strengthening. Also, remote sensing of climate elements could enhance surface observations.

Group 3 a) More stakeholder involvement needed to identify climate information gaps. b) More information on disagreements between different climate analyses. c) C-CIARN Regions and Sectors need to pro-actively get information from stakeholders and decision-makers on: a. Current vulnerability based on historical climate extremes. b. Stakeholder knowledge of historical climate extremes c. Climate-related datasets that could be made available widely d. Needs for future climate information

Group 3 Question 3. a) Expanded and improved interface between Scenarios Facility and users. b) Scenarios should consist of information useful to stakeholders as well as modellers. c) Need to identify whether existing communities or sectors will experience extremes that have never been experienced before. d) Scenarios need to: a. Provide plausible information to allow stakeholders to assess the change in risk of future impacts. b. Focus on multiple variables. c. Provide output focussed on user needs.

Group 3 Ensure “extreme” scientists improve their interscientific communication Question 6. a) Paleo climate is necessary to increase our knowledge of regional climate and its variability. b) Paleo climate useful in increasing user confidence in GCM and RCM “predictions”. Question 7. Uncertainty information is needed.

Group 3 a) Since some impacts models are more sensitive than others to climate scenario impacts, the amount of “certainty” needs will vary with the user. b) Need some measure of the attribution of uncertainty in a scenario. Question 8. a) Downscaling is important, but deriving extremes that are useful for individual users from these outputs is problematic. b) Information on tools and methodologies for downscaling need to be provided also, along with consultation on how to use downscaled data.

Group 3 c) Downscaled data should also include information from analogues and adjustment of historical variability and extremes. Question 13. a) Scenarios facility should continue. b) Scenarios Facility needs to immediately engage stakeholders to define its needs. c) Scenarios Facility should provide access to paleoclimate information. d) Scenarios Facility should provide qualitative assessment GCM suitability for different areas of Canada, or perhaps which ones should be used for ensemble “forecasting.”

Group 3 e) Scenarios Facility should post output from RCMs from Canada and other countries when available. f) A comparison of RCMs is needed for Canada. e) Scenarios Facility should post output from RCMs from Canada and other countries when available. g) Information on strength and weaknesses of NCEP and other re-analyses. h) A standard evaluation protocol is needed for all scenario tools.

Group 4 Chair: Gary Lines (EC Atlantic) Adam Fenech (EC) Rapporteur: Andre St-Hilaire (INRS-ETE, Ouranos).Alain Bourque (Ouranos)Clair Goodess (UK Stardex)Van Nguyen (McGill, Brace Centre)Bill Girling (Manitoba Hydro)Sam Gameda (Ag Can Ottawa)Denise Neilsen (Ag Can BC)Trevor Murdoch (CICS-floater)

1a. Most important aspects of climate variability and extreme events Point-scale information Micro-climate of island states, sub-RCM grid Extreme topography of BC ( mm) Extreme wind speeds building design/ fire risk Wind direction eg fire spread, air quality Extremes of precipitation (snow accumulation) Sequencing of wet/dry-days and spells Multi-season droughts Disaggregation to sub-daily eg. PMP Sea-level rise and saltwater intrusion

1b. Level of understanding of current vulnerabilities to climate change Limited data availability restricts knowledge Long-term, homogeneous records Sparse networks and getting sparser Ungauged watersheds Meta information on land-use, management Qualitative understanding in many sectors Operational rules for water plants Engineering design

1c. Relevance of long-term climate variability Lack of confidence in model variability Historic ranges useful Best to have tool-box full of techniques

2. Which variables should be the focus Not really possible to short-list but if pushed: Precipitation Temperature Wind speeds Local sea-level rise

3. Understanding of ‘scenarios of climate variability and extremes’ Format: time-series, return periods, thresholds Diverse users, diverse needs Time-series can give all of the above Ensembles help express uncertainty of model Some indices can downscaled directly

6. Should we place more reliance on information from past climates? Not at the expense of other activities Merits more effort, provided in usable format Past not neccesarily a useful analogue but may Help understanding of large-scale processes

7. Should information on uncertainty be provided? Yes. IPCC classes helpful eg ‘Highly likely’ Regional skill scores for various GCMs, RCMs

8. Downscaling a viable option? Yes. No better alternative for many applications Scenarios (+liability!!!) = 1/9 Tools = 8/9 Downscaling can incorporate local knowledge Opportunity to build capacity Support and training critical

13. National strategies to develop scenarios of extremes and variability More investment in monitoring/data networks National coordination, research at province level Networks could mimic EU groups Single scenarios centre providing data + training More capacity to develop/critique tools in-house Broader network of local ‘trainers’ Partnership of Federal Government, Provincial and stakeholders Concerted/sustained links to international groups WMO endorsement of tools/techniques

Group 5 Breakout Group Questions

Group 5 1. Current methods for analysing extremes (useful feedbacks from international projects): Is it necessary to use in an integrated approach between dynamical and statistical downscaling tools to analyse extremes? 2. How do we deal with extremes in a non- stationary climate? 3. Do extremes in a nordic climate require special attention?

Group 5 1. What recommendations are suggested for a national strategy to develop scenarios of extremes and climate variability (e.g., national/international collaboration, collaborative projects, tool development, bridges between historical-paleo data groups, modelling groups, statisticians, and I&A users)? Impact res. Projects may reveal weaknesses in current climate modelling approaches as well as uncertainty in impact models. Climate model may be improved by feeding back these weaknesses to the modellers.

Group 5 Practical user’s guide to GCM and RCM outputs. Some of it exists on CCIS site but more may be required. A lot of piecemeal approach thus far. A more integrated approach is required with a national scope. There should be a national body to establish a link between scientific community and IA. (CCAF and Adaptation groups have initiated such work (CCIARN)).

Group 5 There is a submission on national centre of excellence on CC (research focus but CCIARN and Ouranos are involved) Regional efforts in networking. Should there be an opportunity to organize a national body as funding will be restructured in the near future? Note that NSERC has a international fund. This is an opportunity. There is a new project on Ensembles

Group 5 There are two types of users: science but also easy transfer of data for IA. Must add non complex info sheets for IA. Not necessarily a CCIS job. Perhaps three levels or pre-digested info (Scenarios/IA Managers, etc.).

Group 5 Impact res. Projects may reveal weaknesses in current climate modelling approaches as well as uncertainty in impact models. Climate model may be improved by feeding back these weaknesses to the modellers. Practical user’s guide to GCM and RCM outputs. Some of it exists on CCIS site but more may be required. A lot of piecemeal approach thus far. A more integrated approach is required with a national scope.

Group 5 There should be a national body to establish a link between scientific community and IA. (CCAF and Adaptation groups have initiated such work (CCIARN)). There is a submission on national centre of excellence on CC (research focus but CCIARN and Ouranos are involved) Regional efforts in networking. Should there be an opportunity to organize a national body as funding will be restructured in the near future? Note that NSERC has a international fund. This is an opportunity. There is a new project on Ensembles

Summary - Group 5 1.Info available: Long term time series / homogeneity problem 2.Vulnerability Known: NO. Not enough

Group 6 Report

Q1. Most important aspects Need for more consultation with I&A community on this – suggest use of C-CIARN to do this Will likely be regionally variable – not national in scope. Need to include Little Ice Age and MWP in long term database to complement obs data ensuring that we capture 2 key periods New data types mean that proprietary nature of data needs to be respected in development of scenarios (i.e. allow publication before constucting scenarios) CCIS may have a role to play in provision of current climate data (to complement current sources)

Variability & Extreme Scenarios Scenarios are plausible pictures of future climate, its variability and extremes I.e.”future weather scenarios”. Need for data not only for I&A but also to validate model performance on variability & extremes –XT scenarios will be spatially and temporally different from current “mean” scenarios. Selected variables depend on user need and hence require consultation Recognition of the limitations in generating scenarios of desired parameters and work towards finding new ways of using climate scenarios to address questions

Q8. Downscaling Need to make available a suite of several scenarios and different types of tools to develop scenarios to address the varying needs of users –Also provides a means of ensuring that the nature of the uncertainties are well explained as they will be different than for current scenarios of means. The need to check on proper use of the tools Need mechanisms to ensure that tools developed under grants come into the public domain.

Recommendations: National Strategy Should produce the best scenarios we can now and also continue research to refine them over time. ID needs of I&A community – C-CIARN & CCIS to take leadership in process to prioritize needs –CCIS & C-CIARN should put together a proposal asap Develop better understanding of current vulnerabilities –Improved paleo data will be needed to fill in gaps –Also provides better understanding of scenario needs Both suite of extreme scenarios and tools for developing such scenarios should be provided to users Recommend renewal of funding for next phase of CCIS

Recommendations: Continued In developing research program, should use results focused strategic approach (including competition within this framework where appropriate) –Include role for CCIS & advisory committee within this strategy Preference is for an integrated funding system that encourages investment from industry/others