- Chair, Icelandic Climate Council
Halldór is the Chair of the Icelandic Climate Council. Before retiring in 2018 he served in strategic positions at the UN Climate Change Secretariat for fourteen years. This included managing substantive support to international negotiations during a pivotal period of transformation in the global climate regime, which culminated in the adoption of the Paris Agreement in 2015. In that capacity he also contributed to the conception of the global climate action agenda and managed the interface with the scientific assessment function of the Intergovernmental Panel on Climate Change (IPCC).
Before joining the secretariat, Halldór served as the Chair of the UNFCCC Subsidiary Body for Scientific and Technological Advice (SBSTA) for a two-year term. He holds a Ph.D. in Plant Ecophysiology from Utah State University. His research activities include studies of nitrogen cycling, the impact of elevated carbon dioxide on the carbon balance of trees in situ and measurements of fluxes of carbon dioxide and water over crops and forest canopies and of methane from Arctic wetlands.