Project Document An assessment of the economic and social impacts of climate change on the water sector in the Caribbean Economic Commission for Latin America and the Caribbean (ECLAC) The views expressed in this document, which has been reproduced without formal editing, are those of the author and do not necessarily reflect those of the Organization. Acknowledgements The present study was prepared by Juan Llanes-Regueiro. Notes and explanations of symbols: A full stop (.) is used to indicate decimals The use of a hyphen (-) between years, for example, 2010-2019, signifies an annual average for the calendar years involved, including the beginning and ending years, unless otherwise specified. The word “dollar” refers to United States dollars, unless otherwise specified. The term “billion” refers to a thousand million. The boundaries and place names shown and the designations used on maps do not imply official endorsement or acceptance by the United Nations. LC/CAR/L399 Copyright © United Nations. March 2013. All rights reserved Printed at United Nations, Port of Spain, Trinidad and Tobago ECLAC – Project Documents collection An assessment of the economic and social impacts of climate change... Contents Executive summary ..................................................................................................................................... viii I. Introduction ................................................................................................................................................. 1 A. Literature review ............................................................................................................................... 1 1. First group ................................................................................................................................. 2 2. Local and Caribbean regional literature ..................................................................................... 2 B. Methodology ..................................................................................................................................... 3 1. Climate ...................................................................................................................................... 3 2. Water availability ...................................................................................................................... 4 C. Results 6 1. Water, sustainability and open, stable systems .......................................................................... 6 II. The hydrological cycle and climate change ............................................................................................... 8 A. Observed changes and evidence in the hydrological cycle ............................................................. 10 B. The central role of water.................................................................................................................. 11 C. Climate and the hydrological cycle in the Caribbean ...................................................................... 13 1. Climate and hydrometoreological characteristics .................................................................... 13 III. Water resources in the Caribbean ........................................................................................................... 35 A. Caribbean hydrological characteristics ........................................................................................... 36 B. Hydrological drought ...................................................................................................................... 39 C. Hydrological balance methodology ................................................................................................. 41 D. Water balance baseline 1961 – 1990 ............................................................................................... 42 IV. Climate change impacts on Caribbean water resources ......................................................................... 45 A. IPCC scenarios ................................................................................................................................ 45 B. The use of scenarios in water resource management ....................................................................... 46 C. The probable future: Caribbean hydrological scenario .................................................................... 47 1. Caribbean water balance 2050 - 2100 ...................................................................................... 47 2. Groundwater ............................................................................................................................ 62 D. Water management .......................................................................................................................... 64 1. Aspects of water management ................................................................................................. 65 2. Water management and climate change - precipitation reduction, temperature increases and saltwater intrusion ............................................................................................................... 66 iii ECLAC – Project Documents collection An assessment of the economic and social impacts of climate change... 3. Water supply in the Caribbean ................................................................................................ 66 E. Scenarios, water demand estimates and water balances for the Caribbean ..................................... 68 V. Cost benefit analysis of adaptation and mitigation: levelized costs and multi-criteria assessment ......... 73 A. Desalination .................................................................................................................................... 74 1. Energy options considered for systems of sea and brackish water desalination ...................... 75 B. Economies of scale .......................................................................................................................... 77 1. Adaptation in agriculture: changing crop policies ................................................................... 78 2. Water harvesting and the construction of small water reservoirs ............................................ 79 3. Wastewater reuse and recycling .............................................................................................. 81 4. Water harvesting and catchment .............................................................................................. 81 5. Water saving ............................................................................................................................ 84 6. Multi-criteria assessment ......................................................................................................... 84 VI. Conclusions and recommendations ........................................................................................................ 87 Bibliography ................................................................................................................................................. 89 Annexes ........................................................................................................................................................ 93 Annex 1 Extreme events ...................................................................................................................... 94 Annex 2 Modelling results ................................................................................................................... 98 Tables Table 1 Worldwide water use estimates, 1950-2000 .......................................................................... 7 Table 2 Caribbean monthly distribution of precipitation, 1961-1990 .............................................. 21 Table 3 Years affected with moderate or severe precipitation deficit in june affecting more than one fifth of the country, territory or Caribbean area........................................... 31 Table 4 influence of high precipitation in annual precipitation, 1961-1990, Pinar del Río. Cuba, Western District .................................................................................................................. 33 Table 5 Variability of potential water resources in countries of Mesoamerica and the Caribbean .. 40 Table 6 Water Balance 1961-1990. Selected gridded areas in the Caribbean .................................. 43 Table 7 Water Balance 1961 - 1990. Countries of ECLAC Report, 2011 ....................................... 44 Table 8 SRES A2 and B2 emissions scenarios ................................................................................ 45 Table 9 Caribbean water balance. Gridded area. Baseline 1961 – 1990. Scenarios A2 & B2 (2050 & 2100) ..................................................................................................... 51 Table 10 Cuba : Water balance. Gridded area. Baseline 1961 – 1990 Scenarios A2 & B2 (2050 & 2100) ................................................................................................................................... 52 Table 11 Belize water balance. Gridded area. Baseline 1961 – 1990 scenarios A2 & B2 (2050 & 2100) ................................................................................................................................... 52 Table 12 Jamaica water balance. Gridded area. Baseline 1961 – 1990. Scenarios A2 & B2 (2050 & 2100) ....................................................................................................