. I . G . C . I . The Effects of Climate Change and Variation in New Zealand An Assessment Using the CLIMPACTS System R.A. Warrick, G.J. Kenny and J.J. Harman (editors) June 2001 Copyright ã 2001: International Global Change Institute (IGCI) The University of Waikato Private Bag 3105 Hamilton New Zealand Phone: +64 7 858 5647 Fax: +64 7 858 5689 Printed by: Waikato Print The University of Waikato Private Bag 3105 Hamilton New Zealand ISBN 0-473-07988-7 The Effects of Climate Change and Variation in New Zealand An Assessment Using the CLIMPACTS System R.A. Warrick, G.J. Kenny and J.J. Harman (editors) International Global Change Institute (IGCI) University of Waikato Hamilton, New Zealand June 2001 1 Acknowledgements Since 1993, there have been a number of CLIMPACTS team members who have contributed substantially to its development, but who are now no longer actively involved in the Programme. These include G. Sims (who originally engineered the software for the CLIMPACTS system), M. Camillieri and J. de Ruiter. In addition, there have been a number of external individuals and organisations, while not formally part of CLIMPACTS, have graciously contributed their time, ideas, models and/or data to its development, including: T.M.L. Wigley (National Centre for Atmospheric Research, USA); M. Hulme (University of East Anglia, UK); A.B. Pittock, P. Whetton and R. Jones (CSIRO Division of Atmospheric Research); J. Leathwick (Landcare); M.A. Semenov (IACR Long Ashton Research Station, BBSRC, UK); the Ministry for the Environment; Environment Canterbury and Environment Waikato. The research that provided the basis for the present volume would not have been possible without the support provided to the CLIMPACTS Programme by the New Zealand Foundation for Research, Science and Technology. To all, the authors of this report extend their gratitude. Richard Warrick CLIMPACTS Programme Leader International Global Change Institute (IGCI) University of Waikato Hamilton, New Zealand June 2001 iii iv Contents Acknowledgements ................................................................................................................. iii Contents ...................................................................................................................................v List of Figures........................................................................................................................ xi List of Boxes and Tables ........................................................................................................xv Chapter 1: Introduction — The CLIMPACTS Programme and Method................................ 1 G.J. Kenny, J.J. Harman and R.A. Warrick 1 Introduction to the CLIMPACTS Assessment Report............................................................ 1 The CLIMPACTS Programme.............................................................................................. 1 Why Use an Integrated Assessment Model?.......................................................................... 2 The CLIMPACTS System .................................................................................................... 2 The National-Scale Capacity ............................................................................................. 5 The Site-Scale Capacity .................................................................................................... 5 The Regional-Scale Capacity............................................................................................. 5 The Advantages of the CLIMPACTS System .................................................................... 6 Contents and Structure of this Assessment Report................................................................. 6 Scenarios Used in this Assessment Report ............................................................................ 7 Important Limitations to this Assessment.............................................................................. 8 References............................................................................................................................ 98 Chapter 2: The New Zealand Climate - Present and Future ................................................ 11 A.B. Mullan, M.J. Salinger, C.S. Thompson and A.S. Porteous Observed Climate ............................................................................................................... 11 Observed Climate Trends ................................................................................................ 11 Daily Temperature and Rainfall Extremes ....................................................................... 14 Scenarios of Climate Change and Variability ...................................................................... 16 Monthly Scenario Patterns............................................................................................... 17 Daily Scenarios ............................................................................................................... 19 Future Climate.................................................................................................................... 19 Future Mean Changes...................................................................................................... 22 Future Changes in Extremes ............................................................................................ 23 Conclusions........................................................................................................................ 24 Gaps and Future Directions of CLIMPACTS ...................................................................... 24 References.......................................................................................................................... 31 Chapter 3: Changes in Kiwifruit Phenology with Climate.................................................... 33 A.J. Hall, G.J. Kenny, P.T. Austin and H.G. McPherson What is Known? ................................................................................................................. 33 v What does CLIMPACTS Show?......................................................................................... 35 Method ........................................................................................................................... 35 Results ............................................................................................................................ 36 Dates of Budbreak, Flowering, and Maturity................................................................ 36 Flowering: Requires Cool Winters ............................................................................... 38 Fruit Dry Matter: Requires Warm Growing Season ...................................................... 39 Effect of GCM.................................................................................................................... 39 Effect of SOI ...................................................................................................................... 40 Spatial Analysis.................................................................................................................. 41 Summary ............................................................................................................................ 44 Effect of Climate Change on ‘Hayward’ Kiwifruit Production...................................... 44 Effect of Different Scenarios and GCMs on Model Predictions .................................... 44 Effect of SOI ............................................................................................................... 44 Links to Policy and Adaptation ........................................................................................... 44 Key Uncertainties, and Future Research Directions ............................................................. 45 References.......................................................................................................................... 46 Chapter 4: Temperature Impacts on Development of Apple Fruits ...................................... 47 P.T. Austin and A.J. Hall Introduction........................................................................................................................ 47 What is Known? ................................................................................................................. 47 Sensitivity to Climate ...................................................................................................... 47 What Kinds of Changes in Climate Would Imply Substantial Changes?........................... 48 What does CLIMPACTS Show?......................................................................................... 48 Methods .......................................................................................................................... 48 Results ............................................................................................................................ 49 Dates of Bloom and Maturity....................................................................................... 49 Apple Fruit Size at Maturity......................................................................................... 51 Other Factors............................................................................................................... 52 When do the Scenarios Indicate Major Changes? ................................................................ 52 Summary