Cleo Verkuijl is a Senior Scientist at the Stockholm Environment Institute, US. Her research focuses on legal and political dimensions of international climate policy, just and healthy dietary transitions, and animal health and welfare.

Cleo has led several multidisciplinary research projects on One Health and just transition approaches to food systems transformation. She was a coordinating lead author of the UN Environment Programme's (UNEP) “What’s Cooking” Frontiers report, on the potential of novel meat and dairy alternatives. Cleo also served as coordinating lead author of the first two Production Gap Reports. Produced by leading research organizations and UNEP, this is the first assessment of the gap between Paris Agreement targets and countries’ planned coal, oil, and gas production.

A Team Leader and Writer for the Earth Negotiations Bulletin for over a decade, Cleo has closely followed a range of UN negotiating processes, with particular expertise in international climate change and biodiversity governance and the UN Sustainable Development Goals. She has taught environmental law and policy as an Adjunct Professor at Johns Hopkins University in Bologna, and as a tutor for the University of Edinburgh. In 2023–24, she was a visiting research fellow at Harvard Law School’s Animal Law and Policy Programme.

Cleo has also worked for UNEP in Brussels and was a policy officer with the NGO network Climate Action Network International during the Paris climate negotiations. She holds an LL.M. in Global Environment and Climate Law from the University of Edinburgh.