Twenty years have passed since the last atlas of desertification were published. Within that short period, the environment has undergone enormous global changes due largely to human activities. Fortunately, because of the massive increase and growth in the availability of global and regional datasets – and the tools necessary to analyze them – significant progress has been made in understanding human-environment interactions. WAD3 thus begins at a very different place than WAD2 in terms of scientific information and understanding. That said, we are also confronted by the rapidly growing appreciation of the complexity of the land degradation phenomenon and all the human factors that both drive it and are derived from it. As a consequence, WAD3 offers an approach that accommodates and embraces these complexities and provides an information framework from which to pursue solutions that fit specific local situations.