Christensen currently serves as Denmark’s Climate Ambassador. He has previously served as UN Under-Secretary for Global Challenges, where he helped establish the 3GF green growth partnership, before becoming Senior Advisor for Partnerships to UN Secretary-General Ban Ki-moon, leading preparation of the 2014 UN Climate Summit.

He then served as Assistant Secretary General at the United Nations and chef de cabinet to two presidents of the General Assembly (Mogens Lykketoft and Peter Thomson), focusing on implementation of the Paris Agreement and the SDGs. He subsequently advised UN Special Envoys Michael Bloomberg (Climate Action) and Peter Thomson (Ocean). Ambassador Christensen has also served as Denmark’s ambassador to Iran and Egypt.