A Service of Leibniz-Informationszentrum econstor Wirtschaft Leibniz Information Centre Make Your Publications Visible. zbw for Economics Nkonya, Ephraim et al. Working Paper The economics of desertification, land degradation, and drought: Toward an integrated global assessment ZEF Discussion Papers on Development Policy, No. 150 Provided in Cooperation with: Zentrum für Entwicklungsforschung / Center for Development Research (ZEF), University of Bonn Suggested Citation: Nkonya, Ephraim et al. (2011) : The economics of desertification, land degradation, and drought: Toward an integrated global assessment, ZEF Discussion Papers on Development Policy, No. 150, University of Bonn, Center for Development Research (ZEF), Bonn This Version is available at: http://hdl.handle.net/10419/84788 Standard-Nutzungsbedingungen: Terms of use: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Documents in EconStor may be saved and copied for your Zwecken und zum Privatgebrauch gespeichert und kopiert werden. personal and scholarly purposes. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle You are not to copy documents for public or commercial Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich purposes, to exhibit the documents publicly, to make them machen, vertreiben oder anderweitig nutzen. publicly available on the internet, or to distribute or otherwise use the documents in public. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, If the documents have been made available under an Open gelten abweichend von diesen Nutzungsbedingungen die in der dort Content Licence (especially Creative Commons Licences), you genannten Lizenz gewährten Nutzungsrechte. may exercise further usage rights as specified in the indicated licence. www.econstor.eu ZEF-Discussion Papers on Development Policy No. 150 Ephraim Nkonya, Nicolas Gerber, Philipp Baumgartner, Joachim von Braun, Alex De Pinto, Valerie Graw, Edward Kato, Julia Kloos, Teresa Walter The Economics of Desertification, Land Degradation, and Drought Toward an Integrated Global Assessment Bonn, May 2011 The CENTER FOR DEVELOPMENT RESEARCH (ZEF) was established in 1995 as an international, interdisciplinary research institute at the University of Bonn. Research and teaching at ZEF addresses political, economic and ecological development problems. ZEF closely cooperates with national and international partners in research and development organizations. For information, see: www.zef.de. ZEF – Discussion Papers on Development Policy are intended to stimulate discussion among researchers, practitioners and policy makers on current and emerging development issues. Each paper has been exposed to an internal discussion within the Center for Development Research (ZEF) and an external review. The papers mostly reflect work in progress. The Editorial Committee of the ZEF – DISCUSSION PAPERS ON DEVELOPMENT POLICY include Joachim von Braun (Chair), Solvey Gerke, and Manfred Denich. Ephraim Nkonya, Nicolas Gerber, Philipp Baumgartner, Joachim von Braun, Alex De Pinto, Valerie Graw, Edward Kato, Julia Kloos, Teresa Walter, The Economics of Desertification, Land Degradation, and Drought Toward an Integrated Global Assessment, ZEF- Discussion Papers on Development Policy No. 150, Center for Development Research, Bonn, May 2011, pp. 184. ISSN: 1436-9931 Published by: Zentrum für Entwicklungsforschung (ZEF) Center for Development Research Walter-Flex-Straße 3 D – 53113 Bonn Germany Phone: +49-228-73-1861 Fax: +49-228-73-1869 E-Mail: [email protected] www.zef.de The authors: Ephraim Nkonya , International Food Policy Research Institute. Contact: [email protected] Nicolas Gerber , Center for Development Research. Contact: [email protected] Philipp Baumgartner , Center for Development Research. Contact: [email protected] Joachim von Braun , Center for Development Research. Contact: [email protected] Alex De Pinto , International Food Policy Research Institute. Contact: [email protected] Valerie Graw , Center for Development Research. Contact: [email protected] Edward Kato , International Food Policy Research Institute. Contact: [email protected] Julia Kloos , Center for Development Research. Contact: [email protected] Teresa Walter , formerly with Center for Development Research (ZEF), now with Department of Land Use Economics in the Tropics and Subtropics, University of Hohenheim. Contact: teresa.walter@uni- hohenheim.de Contents Acknowledgments vii Executive Summary viii 1. Introduction 1 2. Assessment of Desertification, Land Degradation, and Drought 11 3. Economics of DLDD 60 4. Actors, Incentives, and Institutions Governing Land Management 85 5. Actions for Improvements 93 6. Case Studies 103 7. Partnership Concept 121 8. Conclusions 133 Appendix A: Supplementary Tables 137 Appendix B: Supplementary Figures 151 Abbreviations and Acronyms 153 References 156 iii List of Figures Table 2.1—GLASOD (1991) extent of human-induced soil degradation (in million hectares) 13 Table 2.2—Nitrogen application rates in selected eastern and southern African countries 24 Table 2.3—Global land degradation assessment studies 34 Table 2.4—Trends in the spatial extent of drought for various baseline values 38 Table 2.5—Estimated effect of climate change on drought frequency in 2030 39 Table 2.6—Extent and severity of global soil nutrient depletion, 1990–1999 (in million hectares) 41 Table 2.7— Selected variables used to analyze relationships with NDVI 50 Table 2.8—Correlation of NDVI with selected biophysical and socio-economic factors 51 Table 2.9—OLS regression of mean NDVI on selected biophysical and socio-economic variables 54 Table 3.1—Main valuation techniques 72 Table 3.2—Drought loss, 1900–2004 82 Table 3.3—Economic valuation techniques for the estimation of various types of costs 83 Table 4.1—List of actors affecting land use decisions 88 Table 5.1—Type of land degradation and their solutions 94 Table 5.2—Status, trend, and drivers of pastoral livestock population 98 Table 6.1—Land resources and severity of land degradation 104 Table 6.2—Effects of increased salinity on yields and profit for wheat and cotton, Uzbekistan 105 Table 6.3—Soil loss, yields, and profit for land in different slope classes, Uzbekistan 106 Table 6.4—Adoption rates of land management practices in Kenya and Niger 107 Table 6.5—Trend of total factor productivity growth of major crops, India 114 Table 6.6—Economic loss due to overgrazing, Kenya 116 Table 6.7—Value of tropical forest ecosystem goods and services 120 Table 7.1—Partnerships and the role and strengths of partners in conducting global E-DLDD 126 Table 7.2—Essential climate variable monitoring programs of the terrestrial ecosystem services (part of SB1 and SB2) 129 Table 7.3—Example of E-DLDD research partnership team (SB1) 131 Table A.1—Land degradation assessments on the national level 137 Table A.2—Land degradation assessment on the local and subnational levels 138 Table A.2—Continued 139 Table A.3—Review of studies estimating off-site costs of land degradation (in chronological order) 139 Table A.4—Review of studies estimating the net present value (NPV) of returns to different conservation measures (in chronological order) 144 Table A.5—Costs of land degradation (mainly soil erosion) 149 iv List of Figures Figure 1.1—Conceptual framework for assessing the costs of action versus the costs of inaction regarding DLDD (with net present value outcomes). 4 Figure 1.2—Costs and benefits—Concepts 5 Figure 1.3—Prevention, mitigation, and rehabilitation costs over time 8 Figure 1.4—Illustration of the vicious circle connecting poverty, discount rates, and land degradation 9 Figure 2.1—GLASOD (1991) global assessment of the status of human-induced soil degradation 14 Figure 2.2—Desertification vulnerability 15 Figure 2.3—Areas vulnerable to human-induced desertification 16 Figure 2.4—Loss of annual NPP, GLADA, 1981–2003 20 Figure 2.5—Degraded area as a percentage of total global degraded land area across agroclimatic zones, GLADA, 1981–2003 20 Figure 2.6—Areas most affected by land degradation, GLADA, 1981–2003 21 Figure 2.7—Annual loss of NPP in eastern and southern Africa, 1981–2003 22 Figure 2.8—Yield trend of major cereals in southern Africa, 1981–2009 23 Figure 2.9—Yield trend of major cereals in eastern Africa, 1981–2009 23 Figure 2.10—Cereal yield trend in Cameroon, 1981–2009 23 Figure 2.11—Long-term degradation of green biomass 25 Figure 2.12—Areas affected by human-induced land degradation measured by a declining NDVI (Change in NDVI from 1982–2003 with a three-year base- and endline) 26 Figure 2.13—The six axes of GLADIS: Four biophysical axes (green) and two socioeconomic axes (pink) 27 Figure 2.14—Ecosystem Service Status Index, GLADIS 28 Figure 2.15—Land Degradation Index (LDI), GLADIS 29 Figure 2.16—Biophysical Degradation Index (BDI), GLADIS 29 Figure 2.17—Land Degradation Impact Index (LDII), GLADIS 30 Figure 2.18—Methods for the assessment of land degradation 40 Figure 2.19—Trend of per capita arable land across regions 46 Figure 2.20—Relationship between change in NDVI and population density 51 Figure 2.21—Relationship between GDP and NDVI 52 Figure 2.22—Relationship between government effectiveness and NDVI 52 Figure 2.23—Relationship between fertilizer application and NDVI 53 Figure 2.24—Impact of soil erosion on wheat yield 55 Figure 2.25—Impact of soil erosion on maize yield 55 Figure 2.26—Impact of soil erosion on millet