Africa’s Water Resources Public Disclosure Authorized in a Changing Climate Toward an Operational Perspective Summary Report Public Disclosure Authorized Public Disclosure Authorized June 30, 2011 Africa Region Sustainable Development Department The World Bank Public Disclosure Authorized Supported by AFCRI, AFTWR, AFTEN, Norwegian Trust Fund (NTF)-PSI, TFESSD, and BNPP Disclaimer The findings, interpretations, and conclusions expressed in this report do not necessarily reflect the views of the Executive Directors of the World Bank or the governments they represent. The World Bank does not guarantee the accuracy of the data included in this work. The boundaries, colors, denominations, and other information shown in any map in this work do not imply any judgment on the part of the World Bank concerning the legal status of any territory or the endorsement or acceptance of such boundaries. Table Contents Acknowledgments ............................................................................................................................ v Executive Summary ......................................................................................................................... 1 Chapter 1: Context .................................................................................................................... 4 Chapter 2: Africa’s Water Resources....................................................................................... 10 Chapter 3: Looking Back at Climate Variability ....................................................................... 20 Chapter 4: Looking Ahead at Climate Change ......................................................................... 31 Chapter 5: Development Implications for Water Resources .................................................. 41 Chapter 6: Climate Risk Assessment ....................................................................................... 53 Chapter 7: “Climate Smart” Water Planning: A Case Study and Lessons Learned .................. 61 Glossary of terms ........................................................................................................................... 78 Bibliography ................................................................................................................................... 83 i Figures Figure 1.1 Africa lags in socioeconomic development .................................................................... 4 Figure 1.2 Per capita GDP is very low in Africa ................................................................................ 5 Figure 1.3 Summary framework for climate-smart development planning ................................... 8 Figure 2.1 Many of Africa’s countries have substantial water resources ..................................... 10 Figure 2.2 Major river basins of Africa .......................................................................................... 10 Figure 2.3 Spatial and temporal hydrologic variability in Africa (1960-1995) ............................... 11 Figure 2.4 Current water withdrawals are low (compared to the availability). ............................ 12 Figure 2.5 Most water is used for agriculture ............................................................................... 12 Figure 2.6 Africa has developed little water storage .................................................................... 12 Figure 2.7 Water storage per capita is low.................................................................................... 12 Figure 2.8 Africa has developed little of its hydropower potential ............................................... 13 Figure 2.9 Little of Africa’s irrigation potential has been realized. ............................................... 14 Figure 2.10 Africa’s hydropower potential is large ....................................................................... 15 Figure 2.11 Africa lags the world in safe water supply.................................................................. 16 Figure 2.12 Although population densities are relatively low in Africa, there are pockets of high density ........................................................................................................................................... 17 Figure 2.13 GDP and population distribution in Africa ................................................................. 17 Figure 2.14 African wetlands ......................................................................................................... 18 Figure 2.15 In places like Darfur, water challenges are dire ......................................................... 19 Figure 3.1 Köppen-Geiger climate classification of Africa and characteristics ............................. 20 Figure 3.2 Spatial variation of temperature and precipitation in Africa (1901-2006) .................. 21 Figure 3.3 Month-to-month climate variability in the Niger basin ............................................... 22 Figure 3.4 Year-to-year climate variability in Nigeria .................................................................... 22 Figure 3.5 Runoff is high in sub-basins of the Congo basin and parts of West Africa ................... 22 Figure 3.6 Many African countries are routinely devastated by droughts and floods.................. 23 Figure 3.7 Kenya: a history of floods and droughts ....................................................................... 24 Figure 3.8 Comparison of stream flow variability along the Niger River and Benue Tributary .... 24 Figure 3.9 Gradually breaking the variability curse ....................................................................... 25 Figure 3.10 Tracks and intensity of tropical storms—storm impacts are localized in southeastern Africa ............................................................................................................................................. 26 Figure 3.11 Levels in Lake Victoria have varied significantly over time in response to climatic phenomena ................................................................................................................................... 27 Figure 3.12 The ENSO phenomenon also influences Africa's climate ........................................... 27 Figure 3.13 Ethiopia's devastating droughts are strongly correlated with El Niño ....................... 28 Figure 3.14 Trends in annual rainfall (mm) ................................................................................... 28 Figure 4.1 Greenhouse gas emissions (excluding land use) in 2005 ............................................. 31 Figure 4.2 Land use change is a significant part of African GHG emissions .................................. 32 Figure 4.3 Estimates of global warming vary substantially ........................................................... 33 ii Figure 4.4 Models agree temperatures will increase but the level and the spatial distribution of the increase vary considerably across models .............................................................................. 34 Figure 4.5 Precipitation change in Africa by the 2050s—which GCM is right? ............................. 35 Figure 4.6 Different crystal balls tell different fortunes for the Nile Basin ................................... 36 Figure 4.7 Historical and projected monthly precipitation for four river basins in Africa. ........... 37 Figure 4.8 Comparison of historical and projected precipitation time series for West Africa...... 37 Figure 4.9 Possible runoff changes in Africa ................................................................................. 38 Figure 4.10 Sea levels are expected to rise ................................................................................... 39 Figure 4.11 Some coastal areas in Africa are very vulnerable to impacts of sea level rise ........... 40 Figure 5.1 Regions of Sub-Saharan Africa referenced in Table 5.1 ............................................... 42 Figure 5.2 Countries prone to various types of climate risks ........................................................ 43 Figure 5.3 Impact of climate change on agricultural productivity (without carbon fertilization). 44 Figure 5.4 Impact of a rise in sea level (1 m) and a storm surge (100-year high) on the coastal population ..................................................................................................................................... 46 Figure 5.5 An example of storm surge enhancement with sea level rise (Mozambique) ............. 46 Figure 5.6 Projected change in consecutive dry days by 2050 (number of days) ......................... 47 Figure 5.7 Projected changes in agricultural output potential in different areas ......................... 48 Figure 5.8 Percentage of the country population with livelihoods dependent on agriculture..... 48 Figure 5.9 Storage-yield scenarios under various SRES scenarios ................................................ 49 Figure 5.10 Possible hydropower impacts on Ethiopian hydropower generation under four GCMs ....................................................................................................................................................... 49 Figure 5.11 Malaria prone areas of Africa ..................................................................................... 50 Figure 5.12 The spatial extent of Mt Kilimanjaro glacier in 1976 and in 2000 .............................. 51 Figure 6.1 Proposed climate risk assessment methodology ........................................................