Sand dunes in arid regions are significant mobile landforms which require adaptation and mitigation strategies for protecting human infrastructure and economic assets from encroachment, and which play a significant role in desertification and atmospheric dust emissions. Here we show how the shape, migration speed and direction of active desert dunes around the world are projected to change by the end of this century, in response to shifts in sand-moving wind regime associated with climate change under the SSP5-8.5 scenario. We find significant transformations in dune dynamics for many sand seas and dune fields across the Sahara, The Horn of Africa, the Southern Arabian Peninsula, South-Asia, China, and Australia – as well as increased potential of sand sea expansion and re-activation of dormant dune fields – which we can link to alterations in the Hadley circulation, extra-tropical cyclone activity, and monsoon systems resulting from global warming.