Data and artificial intelligence have a vital role to play in helping us understand and tackle this climate crisis, from predicting extreme weather events, to improving the energy efficiency of our homes and helping to identify deforestation. However, as with data systems at large, individuals and communities tend to have little say in how data is collected, used and shared for climate action. Data trusts and other forms of ‘bottom-up’ data stewardship have emerged to reverse this trend and empower people to take part in the data economy. This report sets out the work undertaken for the project ‘Data trusts in climate’, completed between November 2021 and March 2022. The project was commissioned by the Global Partnership on Artificial Intelligence (GPAI) and delivered in partnership by the Open Data Institute (ODI) and Aapti Institute, with support from the Data Trusts Initiative. It consisted of a literature review, expert interviews and a co-design process involving more than 50 organisations from around the world.