In many parts of the world the quality of land is decreasing, thereby limiting its capacity to provide the manifold goods and services humanity depends on for existence. It is estimated that the health and livelihoods of an estimated 1.5 billion people are currently threatened through the negative impacts of land degradation.

Alarmed by the Sahelian drought in the early 1970s, the global community made first attempts to determine and map the extent of land degradation in the world's drylands. Until today, several more efforts have been made to assess state and trends in global land and soils. Over time, the scope widened from drylands to total terrestrial land, and definitions of land degradation moved from production based aspects to the evaluation of ecosystem goods and services, and the inclusion of economic and socio-cultural dimensions.

Land degradation is a global issue with local solutions. Therefore, a concerted global effort on the post-2015 development agenda should also include the many promising SLM technologies and approaches that are already applied. This would help empower the global community to learn from each other, and contribute to building resilience at local, national, and regional levels.

This document portrays the major land and soil degradation assessments of the past and critically evaluates their results. Another section is devoted to the various methodologies that can be applied, including their strengths and weaknesses. It finally explores promising potential corner stones of future assessments, with particular reference to the SDG target of Land Degradation Neutrality.