CLIMATE CHANGE IMPACTS AND ADAPTATION: ROLE OF EXTREME EVENTS Stewart J. Cohen 1) Adaptation & Impacts Research Group, Environment Canada 2) Institute for Resources Environment & Sustainability University of British Columbia, Vancouver [ Presentation at the Environment Canada Scenarios Workshop, Victoria, October 16-17, 2003.

Prologue Impacts and adaptation research is not a linear process Climate scenarios provider as member of interdisciplinary teams Role of climate change scenarios is to help produce impacts ‘futures’ Must meet needs of a wide range of potential users (range of climate parameters, spatial resolution, link with current observation network) “Extreme event” not necessarily about magnitude; could be about timing, context, etc. Need to establish “best practice” standards for production & application of extreme climate scenario products

IPCC-TAR, Synthesis Report (2001), Fig. 1-1

Three Questions for Climate Impact Assessment What If? In a scenario of climate change, what would the impacts be if there was no proactive adaptation? So What? Does the impacts scenario make a difference to stakeholders’ visions of the future? What Should Be Done? What potential responses to this scenario can be identified?

IPCC-TAR, WG2 (2001), Fig Adaptation Questions

IPCC-TAR, WG2 (2001), Fig Climate Change, Variability, Extremes and Coping Range

Trends in the U.S. reflect peaks from individual events; no evidence of any trends in extreme event frequency or severity; increased losses due to population growth & development decisions Trends of per capita extreme event losses in the U.S. (Changnon et al. 2000)

Source: MunichRe

Adaptation Lessons from Infrastructure Failure 1998 Ice Storm

Imperfect Adaptation Weather-related Road Accident Risk

Weather affects road safety Billions invested annually Large residual risk remains Weather-related road accident risk (for Halifax-Dartmouth, Ottawa, Regina) (relative to dry/non-precipitation conditions) Source: Andrey, et al Weather-related Road Accident Risk

FROM GLOBAL TO LOCAL: Examples of Regional Climate Impacts & Adaptation in North America (IPCC-TAR WGII, 2001)

Reasons for concern about projected climate change impacts (IPCC, (2001)WGII Summary for Policymakers)

Economic Costs of Climate Change Impacts & Adaptation; (IPCC, WGII-Ch. 19, 2001) Note: based on changes in mean temperature; reflects differences in assumptions about adaptation

Impact & Adaptation Assessment is Not a Linear Process How to define the problem? Role of researchers & “actors” (stakeholders) Scaling from global to regional? Climate change scenarios (means, timing, other statistics?) Socio-economic scenarios (population, development, “adaptive capacity”…) How to choose biophysical impact models (crop, hydrology, forest growth, etc.)? Data, scale, resolution, processes… How to choose decision-support tools (economics, engineering, expert judgment)? How to link with regional/national policy? Context, dialogue, context, dialogue…

Examples from Studies of Observed and Scenario Events Drought of 2003; fires Mackenzie Basin Impact Study (MBIS); fires, storm surges Mountain pine beetle in British Columbia; warm winters and future potential Okanagan water resources; will drought conditions become more common?

The Drought of 2003; Lessons for Climate Change Impacts/Adaptation?

Okanagan Mountain Park Fire Okanagan-Urban Wildland Interface Fires of 2003 (Natural Resources Canada)

Fires in British Columbia & Alberta, August 2003

Fire Weather Index Scenario for the 2050s (right) compared with Fire Weather Index for the 1980s (left) Source: Natural Resources Canada Note: scenario of changing extreme event based on changes in mean monthly temperature

Mackenzie Basin Impact Study (MBIS) ( ) Governments – national, regional, indigenous people Industry – energy, forestry, mining NGOs – advocacy (various) Academia – research, training

Scenario changes (GISS transient) to fire weather, BC and Alberta (Kadonaga, 1997; Hartley & Marshall, 1997) 1980s 2050s

Permafrost Thaw & Damage to Road, NWT (2002) Permafrost Thaw After Forest Fire near Norman Wells, NWT (1996)

Climate Change: Implications for the Mackenzie Basin Climate Change scenario includes increased permafrost thaw, longer growing season, increased forest fire risk, and reduction of ice season (storm surges?) Potential constraints on proactive adaptation include use of land for subsistence, winter transportation system, and uncertainty about the future Permafrost thaw scenario (red equals 4 to 5 C increase plus increased snowfall) in the NWT Source: Dyke et al., in Cohen (ed.) 1997.

2001: Mountain pine beetle damage

Areas of susceptible pine and Mountain Pine Beetle (MPB) infestation since 1910 Area of susceptible pine (ha × 10 6 ) MPB outbreak area (ha × 10 3 ) Year Frequent large-scale MPB outbreaks during last century Size of outbreaks correlated with increase in susceptible pine Frequent large-scale MPB outbreaks during last century Size of outbreaks correlated with increase in susceptible pine Source: Allan Carroll Canadian Forest Service

Mountain Pine Beetle – limits Cool summers Winter minimums (below -40°C) -40 Source: Allan Carroll Canadian Forest Service

Very low Low Extreme Moderate High Climatic suitability Climatically suitable habitat for the mountain pine beetle Source: Allan Carroll Canadian Forest Service

Water Management & Climate Change in the Okanagan—Study Framework

Climate Change Scenarios for 50 °N, 120°W (Taylor & Barton, 2003)

Base & scenario mean seasonal flow volumes at Ellis Reservoir (Merritt & Alila, 2003)

Crop water demand for hypothetical hectare of apple at Summerland, for historical and 2050’s scenario climate (Neilsen et al., 2003).

Stakeholder views on adaptation [March 2001] Engaging dialogue to identify adaptation strategies to scenarios of streamflow reductions during the growing season in the Okanagan Basin Web site: Preferred adaptation options among the stakeholders? S tructural (e.g. building upland dams) and social measures (e.g., buy out water licenses) preferred over institutional measures Some implications of their choices? Stakeholders identified the high cost of dams, associated impacts on fisheries, and difficulties in restricting development as possible implications of their adaptation choices.  adaptation dialogue is just beginning...

Evolution of Scenario Application in Impacts/Adaptation Research (a personal journey…) Okanagan Okanagan MBIS Sask. River Gt. Lakes GFDL, GISS 2xCO2 GFDL80 GFDL87 GISS OSU 2xCO2 GFDL R30 CCC1 2XCO2 GISS tr. 1%/year CGCM2 CSIROMk2 HadCM3 A2, B2 CGCM1 ECHAM4 HadCM2 IS92a Ad hoc delivery through NCARAES archive service CCIS (AIRG)

Key Messages Impacts/adaptation research requires an interdisciplinary approach to fully address the range of potential issues that may arise due to climate change; scenario applications must fit into that context. Current applications of ‘mean’ climate scenario products already include derivation of extreme event indicators (e.g. fire weather); future application of extreme climate scenario products could attract new users, BUT beware of simplistic definitions of ‘extremes’ (e.g. drought). There are institutional & social components to vulnerability & adaptation, and this will continue to influence the framing of impacts/adaptation research questions, including the role of climate scenarios.