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Global Assessment of Sand and Dust Storms

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Global Assessment of Sand and Dust Storms Global Assessment of Sand and Dust Storms UNEA Supplementary Information Global Assessment of Sand and Dust Storms Draft Report Not for circulation UNEP Logo WMO logo UNCCD logo ii Contents Table of Contents Contents ..................................................................................................................................... iii 1 Introduction ........................................................................................................................ 1 1.1 Sand and dust storm significance .................................................................................. 1 1.2 Policy context .............................................................................................................. 3 1.3 Aims and scope of the assessment ............................................................................... 4 2 Sand and Dust Storms Processes .......................................................................................... 6 2.1 Sand and dust storm definitions ................................................................................... 6 2.2 Sand and dust storm mechanisms ................................................................................ 7 2.3 Causes of sand and dust storms .................................................................................... 9 2.3.1 Direct drivers in natural ecosystems ................................................................................. 9 2.3.2 Indirect drivers in natural ecosystems ............................................................................ 11 2.3.3 Direct drivers in human-dominated ecosystems ............................................................ 12 2.3.4 Indirect drivers in human-dominated ecosystems ......................................................... 15 2.3.5 Land degradation feedback processes ............................................................................ 18 3 State and Trends ................................................................................................................ 22 3.1 Global picture ............................................................................................................ 22 3.2 Contribution of human activities to dust storms ......................................................... 27 3.3 Regional picture ......................................................................................................... 29 3.3.1 The Sahara, Northern Africa and Southern Europe ........................................................ 30 3.3.2 Middle East and East Africa ............................................................................................. 32 3.3.3 Southern Africa ............................................................................................................... 35 3.3.4 North America ................................................................................................................. 37 3.3.5 South America ................................................................................................................. 38 3.3.6 South Asia ........................................................................................................................ 41 3.3.7 Central and East Asia ....................................................................................................... 43 3.3.8 Australia .......................................................................................................................... 45 4 Impacts and Cost of SDS ..................................................................................................... 47 4.1 Environmental impacts .............................................................................................. 47 4.2 Human health impacts ............................................................................................... 49 4.2.1 Overview ......................................................................................................................... 49 4.2.2 Specific conditions ........................................................................................................... 50 4.3 Economic impacts ...................................................................................................... 53 5 Monitoring, Prediction and Warning Systems for SDS ......................................................... 58 5.1 WMO Sand and Dust Storm Warning Advisory and Assessment System ...................... 62 5.1.1 The SDS-WAS Regional node for Northern Africa, Middle East and Europe .................. 62 5.1.2 The SDS-WAS Regional node for Asia and Central Pacific ............................................... 65 5.1.3 The SDS-WAS Regional Node for Pan-America ............................................................... 70 5.1.4 Barcelona Dust Forecast Centre ...................................................................................... 75 5.2 Copernicus Atmosphere Monitoring Service (CAMS) ................................................... 76 5.3 International Cooperative for Aerosol prediction (ICAP) .............................................. 77 5.4 A Global Dust-Health Early Warning System ............................................................... 78 6 Technical Measures for Mitigating SDS ............................................................................... 81 6.1 Control measures in crop land .................................................................................... 81 6.2 Control measures in rangelands and natural areas ...................................................... 86 iii 6.3 Control measures in industrial settings ....................................................................... 88 6.4 Protection of urban areas and infrastructure .............................................................. 89 6.5 Integrated control strategies ...................................................................................... 91 7 Policy Actions for Mitigating SDS ........................................................................................ 93 7.1 Existing regional and national policy actions ............................................................... 93 7.1.1 SDS regional action plans ................................................................................................ 93 7.1.2 Regional and related national policy actions .................................................................. 94 7.1.3 Regional air pollution policies ......................................................................................... 97 7.2 Existing global policy actions ...................................................................................... 97 7.2.1 The Rio conventions and associated support ................................................................. 98 7.2.2 International environmental law specific to SDS ............................................................ 99 7.2.3 Monitoring, prediction and warning systems for SDS .................................................. 100 7.3 Policy framework for improving SDS actions ............................................................. 102 7.3.1 Context for further policy action – summary of key SDS features ................................ 102 7.3.2 Framework for policy action ......................................................................................... 103 7.3.3 Policy options for improving SDS actions ...................................................................... 105 7.3.4 A global policy response ................................................................................................ 107 8 Appendix: Case Studies .................................................................................................... 109 9 References ....................................................................................................................... 123 iv 1 Introduction 1.1 Sand and dust storm significance Sand and dust storms (SDS) are lower atmosphere events that result from wind erosion liberating sediment participles for the ground surface. Sand storms occur relatively close to the ground surface, but finer dust particles may be lofted kilometres high into the atmosphere, where strong winds transport them long distances. As bare ground is most susceptible to sediment entrainment, these events usually occur in semi-arid and arid areas where vegetation cover is limited. Dust storms may travel thousands of kilometres from source areas, passing over land and ocean, and depositing materials far from their source areas. Dust storm trajectories are part of natural ecological systems in arid and semi-arid regions and rates of aeolian deposition may be of similar magnitude to rates of fluvial and aeolian erosion (Goudie and Middleton 2006). SDS have a number of effects on the environment, both positive and negative: the various interactions are complex and not yet fully understood (Knippertz et al. 2014). Dust affects atmospheric, oceanic, biological, terrestrial and human processes and systems (Washington and Wiggs 2011). For example, dust plays a major role in the earth’s biogeochemical cycles, fertilizing and sustaining both oceans and forests (Goudie 2009). Dust affects the climate system, modifying tropical storm and cyclone intensities (Evan et al. 2006) and changing the earth’s radiative balance, which can cause drought intensification (Han et al. 2008; Highwood and Ryder 2014). On the other hand, dust can enhance precipitation
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