Diversification to adapt to climate change (in Guadiana river basin)

1. Diversification to adapt to climate change (in Guadiana river basin) • Saskia Werners, Wageningen University & Research Centre, NL • F. Incerti, M. Bindi, M. Moriondo, University of Florence, IT • Francesc Cots, Universitat Autonoma de Barcelona, ES Conclusion: Adaptation is inevitable. The climate is inherently uncertain. Adaptation requires a risk management approach. Diversification of activities (here: crops) can reduce climate related risks.

2. Presentation • Why this study: How to live with change and reduce climate related risks • Where: The Guadiana river basin, Spain/Portugal • How: Crop modelling, regional climate scenarios and risk assessment • What: Results • Now what: Conclusions & future work

3. Background: the ADAM project • ADaptation And Mitigation Strategies: Supporting climate policy • www.adamproject.eu • Supported by the European Commission, 6th Framework program of the Research Directorate • 25 partners in Europe & outside, incl Chinese Academy of Sciences • Research on Mitigation, Adaptation, scenarios and policy appraisal • Three regional case studies: Guadiana river in Spain/Portugal-EU, Alxa region in Inner Mongolia-China & Tisza river, Hungary-EU • A first workshop and fieldtrip to the Alxa region will be held later this week. Please contact me if you want to exchange info.

4. Why this study? Goal: • How to adapt to an uncertain climate?This study: Find land use/crop patterns that reduce climate risks • Diversification suggested in various fields as a means to become resilient, cope with shocks (agriculture, ecology, economics) • Study diversification (here: combining different agricultural crops) as adaptation strategy (here: to stabilise farmer income) • Here we define: risk = variance in farmers’ income (less variance -> better adapted) • Future: To extend this example to other land and water uses

5. Why: Gaudiana river

6. Land ecosystem Agriculture Water ecosystem Tourism Industry Domestic sector Where: Gaudiana One of largest basins of Iberian Peninsula, transboundary Portugal - Spain Water consumption is polarised by farming needs (60%), industrial activities (24%) and domestic water supply. Spain (81%), Portugal (19%) Semi arid climate , Strong seasonal variations and periods of drought Main sources of pollution: agricultural, industrial activities and urbanisation. Salinisation problems. River heavily regulated. Alqueva dam and lake. Richness of natural and cultural heritage, incl traditional ‘dehesa’ landscape Water ecosystem

7. Where: Gaudiana Mertola Alqueva lake

8. How: crop model, climate model, risk Simulate crop yields (barley, sunflower, durum wheat, sorghum, maize) with CropSyst (Cropping Systems Simulation Model) specifying a.o. soil properties, fertilizer, irrigation, CO2 concentrat. Simulate for climate scenario baseline years 1961-1990; Future climate scenario: A2 2071-2100. Daily data regional climate model HIRHAM, 12.5km grid resolution (PRUDENCE project) Crop revenue: Mean annual revenue earned from the crops over a 30 year simulation period(gross revenue: price times yield per acre) Risk: variance of revenue of cropping pattern (mix of crops) in area (grid cell) over 30 years (1961-90 or 2071-2100) Aim: find cropping pattern with lowest risk or best revenue risk ratio (similar to portfolio management in investing)

9. Results: crop revenue Average crop revenue ± standard deviation of cropping patterns with different shares of sunflower versus barley Correlation: sunflower-barley: 0.57 (1961-1990) -> 0.71 (2071-2100) *) the optimal combination of risky investments (or Tangent Portfolio in Modern Portfolio Theory)

10. Cartoon: mixing two crops in Gaudiana basin Scenario baseline years 1961-1990; Climate scenario A2 2071-2100 Share barley for lowest risk (variance) in total crop revenue Share barley for best revenue – risk (var.) ratio for total crop revenue

11. Lessons & Conclusions • Word of caution: Analysis & previous figure do NOT include all relevant crops + land uses. Assessment crop revenue very simple; e.g. subsidies not included. Crop selection not only for adaptation. • Risk is not (only) snapshot. For adaptation youhave totake into account a range of climate conditions and how these conditions impact your activities. • Diversification can reduce risk depending on local situation. Given your activities and the climate conditions, there is an upper limit to diversification beyond which risks cannot be ‘diversified away’. • Climate change modifies (co)variance of crops (less yields). Re-evaluation of cropping patterns can provide higher risk security.

12. Thanks! & Discussion Grasses in Antarctica Crops in Ethiopia Contact: werners@mungo.nl Info:www.adamproject.eu

13. Now what? • Check crop yields (model, against statistics) • Check climate scenarios & how typical time period is (ADAM S) • Improve methodology • Include other crops & other land uses • Test in other regions • Reconstruct &compare to historic/spatial profile of diversification • Discuss what determines current land use & land use change

14. Portfolio management • xx