Climate scenarios for semi-arid and sub-humid regions. A comparison of climate scenarios for the dryland regions, in West Africa from 1990 to 2050

Abstract

The identification of climate scenarios for dryland areas in Sub-Saharan West Africa is part of a project to assess the impact of climate change on water availability, agriculture and food security in drylands (ICCD-project). The project is financed by Netherlands Research Programme on Global Air Pollution and Climate Change (NRP) and part of theme 'Vulnerability of Natural and Social Systems for Climate'. The report describes the development and description of climate scenarios by using results from both integrated assessement models (IAMs) and global atmospheric circulation models (GCMs) for climate change. The resulting scenarios will be appropriate for Sub-Saharan West Africa. The report describes a common definiton of drylands, their general characteristics and geographical distribution, and gives an introduction to climate change and its potential impacts on ecosystems, agro-systems and society. To improve the understanding of the existing methods, special attention is given to the various approaches commonly used to simulate the impact. The focus of the report is mainly the climate-change scenario development and the application of IAMs and GCMs, especially the use of comprehensive IMAGE scenarios to dynamically calculate transient impacts at global, regional and sub-regional scale. For most indicators the situation in 1990, the projection for 2050 and the absolute change are presented, both in table and map format. The last part of the report summarises the results for a set of climate indicators for Sub-Saharan West Africa.<br>