1. Towards Local Costing of Climate Change Impacts for Decision Making in Adaptation Alistair Hunt and Tim Taylor, University of Bath, UK Session 32 - Economic Costs of Adapting and not Adapting to Climate Change International Scientific Congress on Climate Change, Copenhagen, March 11, 2009.

2. Research: Overview Objective: provide quantitative estimates of economic welfare costs of CC impacts projected to face stakeholders at local scale, within UK. benefits gained from taking adaptive action. test robustness of methodological components: stakeholder-driven; scenario down-scaling; use of non-market values

3. Impacts and primary stakeholder Impact consideredPrimary Stakeholder Road maintenance in summer (subsidence) and winter (salting - ice) Cambridgeshire County Council Domestic property subsidenceAssociation of British Insurers Historic garden maintenance in Cornwall (lawn mowing and pest control) National Trust Health impacts of hot summers in Hampshire Hampshire County Council

4. Methods Stakeholder role: scoping; data provision; method validation Quantify current vulnerability – analogue data; mix of means and extremes Impact projections to 2100 –4 Down-scaled climate scenarios (correspond to: A1F1, A2, B2 & B1 IPCC SRES) –Socio-economic scenarios evolution of stock-at-risk; prices, and; adaptive capacity

5. Climate Change Impact and Adaptation Costs: A Simplified framework

6. Results Impact costs in annual terms - three 30-year time periods; for 4 climate scenarios –climate change gross & net of socio-economic change, discounted using exponentially declining rates, and undiscounted. –Stakeholders identified adaptation options initial assessment of adaptation cost and its distribution of burden e.g. between private and public sector economic agents.

7. Annual Impact multipliers over baseline (2011–2040 time period, undiscounted) Impact consideredPrimary Stakeholder Road maintenance in summer (subsidence) and; winter (salting - ice) 13 – 15 (-) 1.3 – 1.6 Domestic property subsidence12 - 15 Historic garden maintenance in Cornwall (lawn mowing and pest control) 1.2 – 1.5 Health impacts of hot summers in Hampshire 16 - 18

8. Example: Cost of Building Subsidence in UK

9. Aggregate Benefits & Costs - adaptation options to domestic property subsidence

11. Conclusions Primary stakeholders able to use generated quantitative information in planning processes. Common money metric found to be valuable –At least as important for planning for current vulnerability as for future vulnerability under CC Uncertainty in results provokes different responses according to stakeholder contexts, preferences. –Spread risk across stakeholders e.g. Promote range of responses (property subsidence) –Reactive e.g. Wait for trend to become clear (Gardens) –Proactive e.g. Bid for more financial resources to centre (Health, roads)

12. Conclusions II Down-scaling to sub-national level increases confidence with which stakeholders approach exercise tension with introduced scaling uncertainties Research priority: need to understand economic, and other, factors that determine adaptation response e.g. what is value of information likely to be for different actors?