William Thompson is a Knowledge Exchange Fellow at the Nature-based Solutions Initiative. Here, in collaboration with international research institutions, NGOs and industry, he leads the development of the High Agricultural Reforestation Potential (HARP) Toolkit. HARP will be a set of tools designed to facilitate sustainable reforestation in tropical agricultural landscapes, with a particular focus on cocoa and coffee producing landscapes at forest frontiers. In addition, William is collaborating on the ETH Zurich led Sustain-Cocoa project to evaluate the impacts of forest focused supply chain policies on West African cocoa producers and the remnants of the Guinean forests. William’s broad research interests involve understanding how food and agricultural systems interact with ecosystems, as well as exploring mechanisms by which these systems can be modified to enhance farmer livelihoods, improve food security, mitigate climate change and reverse biodiversity loss. Background: William has diverse experience in food systems and agriculture across research, private sector and international organisations. After a BSc in Biology (University of Bristol), he gained global experience in food sourcing and sustainability with Sainsbury’s Supermarkets in the UK, Costa Rica, Australia and Hong Kong. Seeking to specialise in sustainability issues, William took an MSc in Environmental Technology (Imperial College London) focussing on ecological management. Following this, William worked at the United Nations World Food Programme in Tanzania, where he co-ordinated the on-the-ground establishment of a weather risk transfer mechanism for smallholder maize farmers, as part of the WINnERS project for the Farm to Market Alliance. This led to William completing a doctorate in food systems resilience, at the Sustainable Agroecosystems Group of ETH Zurich where he explored ways to enhance the climate resilience of smallholder farmers engaged in cocoa and banana global food value chains, by integrating social and natural science approaches.