1. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Introduction to Climate Change Scenario Development Dr. Elaine Barrow CCIS Principal Investigator (Science)

2. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada What is a climate change scenario? Definitions: “…a coherent, internally consistent and plausible description of a possible future state of the world…” [Parry & Carter, 1998] “…a plausible future climate that has been constructed for explicit use in investigating the potential consequences of anthropogenic climate change…” [IPCC TAR, 2001]

3. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada A climate scenario is not a prediction of future climate!

4. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Why do we need climate change scenarios? To provide data for VIA assessment studies To act as an awareness-raising device To aid strategic planning and/or policy formation To scope the range of plausible futures To structure our knowledge (or ignorance) of the future To explore the implications of decisions

5. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Key component of a framework for conducting integrated assessment of climate change for policy applications

6. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada What are the challenges of developing climate scenarios? simple to obtain, interpret and apply provide sufficient information for VIA assessments physically plausible and spatially compatible consistent with the broad range of global warming projections reflect the potential range of future regional climate change, i.e., be representative of the range of uncertainty in projections

7. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada What you want … … typically is daily weather for a particular place for some future year

8. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Three ways... Incremental (arbitrary, synthetic) scenarios Analogue scenarios Scenarios from global climate models (GCMs) COMPLEXITYCOMPLEXITY

9. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Incremental Scenarios for sensitivity studies  T=2°C Can provide valuable information about: sensitivity thresholds or discontinuities of response tolerable climate change

10. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada ADVANTAGES: simple to construct and apply, allow relative sensitivity of impacts sectors/models to be explored DISADVANTAGES: arbitrary (and unrealistic) changes, may be inconsistent with uncertainty range Yield change (t/ha) of Valencia orange in response to changing temperature and CO 2 concentration [Source: Rosenzweig et al. (1996)]

11. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Identification of recorded climate regimes which may resemble the future climate in a given region Assumption: climate will respond in the same way to a unit change in forcing despite its source and even if boundary conditions differ Analogue Scenarios

12. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Identify regions which today have a climate analogous to that anticipated in the study region in the future Spatial Analogues [Source: Parry & Carter, 1988] Approach restricted by frequent lack of correspondence between other non-climatic features of the two regions Causes of the analogue climate likely different from the causes of future climate change

13. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Use climate information from a past time period as an analogue of possible future climate Palaeoclimatic Instrumental Temporal Analogues

14. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Palaeoclimatic Analogues Use information from the geological record - fossils, sedimentary deposits - to reconstruct past climates mid-Holocene, 5-6k BP, 1°C warmer last (Eemian) interglacial, 125k BP, approx. 2°C warmer Pliocene, 3-4m BP, 3-4°C warmer IPCC, 1990

15. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Palaeoclimatic Analogues changes in the past unlikely to have been caused by increased GHG concentrations data and resolution generally insufficient, i.e., extremely unlikely to get daily resolution and individual site information uncertainty about the quality of palaeoclimatic reconstructions higher resolution (and most recent) data generally lie at the low end of the range of anticipated future climatic warming

16. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Past periods of observed global- or hemispheric- scale warmth used as an analogue for the future Instrumental Analogues Difference =0.4°C Lough et al., 1983 Northern Hemisphere temperature record

17. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Instrumental Analogues The 1930s in the North American Great Plains have frequently been used as an analogue for the future. Mean temperature (°C) Precipitation (mm) Differences between 1931-1940 average and 1951-1980 average in the MINK states (Easterling et al., 1992)

18. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Palmer Drought Severity Index (PSDI) for the US Corn Belt, 1930- 1980. [Source: Rosenberg et al., 1993] Instrumental Analogues

19. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Rice-growing areas in Japan Instrumental Analogues Base, 1951-1980Warm decade, 1921-1930 0.4°C warmer than base

20. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Instrumental Analogues ADVANTAGES data available on a daily and local scale scenario changes in climate actually observed and so are internally consistent and physically plausible DISADVANTAGES climate anomalies during the past century have been fairly minor cf. anticipated future changes anomalies probably associated with naturally- occurring changes in atmospheric circulation rather than changes in GHG concentrations

21. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada GCMs are the “…only credible tools currently available for simulating the physical processes that determine global climate...” [IPCC] [Source: David Viner, UK Climate Impacts LINK Project] Scenarios from GCMs

22. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada What do GCMs do? Growth in population, energy demand, changes in technology and land-use/cover Greenhouse gas emissions Atmospheric GHG concentrations Future climate projections Energy-economy models Carbon cycle and other chemical models Climate models Simulate the response of the global climate system to changes in atmospheric composition

23. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada GCM evolution EQUILIBRIUM EXPERIMENTS TRANSIENT EXPERIMENTS COLD START WARM START 1980s late 1980s early 1990s

24. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Warm start GCMs

25. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada CGCM1

26. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Vintage Resolution Validity Representativeness of results [Source: Smith and Hulme, 1998] Which GCM should I use?

27. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada BUT... Climate models are not accurate Different GCMs give different results The future is uncertain - it is expensive to run many climate change experiments using different emissions scenarios Climate model results are not at a fine enough spatial scale

28. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Climate models are not accurate...

29. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada t2t2 t1t1 Climate change integration Time Global mean temperature (°C) t 1 is typically 1961-1990 t 2 is a future time period, e.g., 2040-2069, representing the 2050s  T=t 2 -t 1 Some models exhibit large inter-decadal variability, so average over 30 years to capture longer-term trend. so we cannot use their output directly...

30. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada IPCC-TGCIA recommend 1961-1990 as the climatological baseline Role in climate scenario construction: serves as a reference period from which estimated future change in climate is calculated used to define the observed present-day climate with which climate change scenario information is usually combined

31. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Specifying the Baseline Important for: characterising the prevailing conditions under which an exposure unit functions and to which it must adapt describing average conditions, spatial and temporal variability and anomalous events, some of which can cause significant impacts calibrating and testing impact models across the current range of variability identifying possible ongoing trends or cycles specifying the reference situation with which to compare future changes

32. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada [Source: Hadley Centre for Climate Prediction and Research, UK Met. Office] Sources of Uncertainty Cascade of uncertainty

33. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada The future is uncertain... IPCC Special Report on Emissions Scenarios (2000)

34. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada The future is uncertain...

35. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada The future is uncertain... 1.4-5.8°C

36. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada The future is uncertain... 0.09-0.88m

37. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada SRES climate change

38. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada SRES climate change

39. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Different GCMs give different results …

40. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Different GCMs give different results …

41. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Which scenarios? Cooler, wetter Cooler, drierWarmer, drier Warmer, wetter

42. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Risk assessment approach ADVANTAGES makes (some) uncertainties explicit good for risk assessment can be applied at different scales DISADVANTAGES not yet a well developed methodology requires a lot of model data to develop expert assumptions still needed

43. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Effect of scenario resolution on impact outcome Spatial Scale of Scenarios [Source: IPCC, WGI, Chapter 13]

44. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada 1.What climate variables are essential for your study? 2.How many scenarios do you want? Which uncertainties are you going to explore? 3.Do you need local data for case studies/sites, or national/regional coverage? 4.What spatial resolution do you really need - 300km, 100km, 50km, 10km, 1km? Can you justify this choice? 5.Do you need changes in average climate, or in variability? 6.Do you need changes in daily weather, or just monthly totals? Scenario Needs

45. The Canadian Climate Impacts Scenarios (CCIS) Project is funded by the Climate Change Action Fund and provides climate change scenarios and related information to the VIA community in Canada Further Reading IPCC TAR - Chapter 13 (www.ipcc.ch) Smith & Hulme - Chapter 3: Handbook on Methods of Climate Change Impacts Assessment and Adaptation Strategies (http://130.37.129.100/english/o_o/instituten/ IVM/research/climatechange/Handbook.htm) Parry & Carter - Climate Impact and Adaptation Assessment. Earthscan, 166pp. IPCC TGCIA Guidelines on Climate Scenarios (currently under revision)