QUEST projects both used and produced an immense variety of global data sets that needed to be shared efficiently between the project teams. These global synthesis data sets are also a key part of QUEST's legacy, providing a powerful way of communicating the results of QUEST among and beyond the UK Earth System research community.

To facilitate this data exchange, and to avoid replication of the often labour-intensive efforts to source and visualize data, QUEST set up the QUEST Earth System Data Initiative - QESDI - a mechanism for easy, centralized access with flexible statistical and visualization tools for consistent processing and presentation of global data sets.