Jun Arima is a Professor in the Graduate School of Public Policy, the University of Tokyo since August 2015.

He currently holds the Professorship at the University of Tokyo, he serves as Project Leader for the 21 st Century Public Policy, a Distinguished Senior Research Fellow at the Asia Pacific Institute of Research and a Consulting Fellow at the Research Institute of Economy, Economy, Trade and Industry, Senior Policy Fellow for Energy and Environment, Economic Research Institute for ASEAN and East Asia(ERIA). He is also a Lead Author of the Intergovernmental Panel of Climate Change (IPCC) 6th Assessment Report.