Some 3.2 billion people, or almost one third of the global population, are affected by desertification and land loss according to the UN’s most senior official dealing with the issue. The loss of land through drought and desertification, which is being driven, in part, by climate change, can have huge impacts on agriculture, development, migration and national and regional economies and sometimes leads to conflict. Ibrahim Thiaw is the Executive Secretary of the UN Convention to Combat Desertification (UNCCD). Daniel Dickinson spoke to him ahead of the World Day to Combat Desertification and Drought, marked annually on 17 June and began by asking him where the fight to hold back desertification should begin.