Hans-Otto Pörtner has been conducting research as a physiologist and microbiologist at the Alfred Wegener Institute in Bremerhaven for more than 25 years and is now one of the world’s leading experts on the impact of climate change on life in the ocean. His scientific career began in Münster and Düsseldorf, where he studied biology and wrote his dissertation in the subfield of animal physiology. After pursuing research in Göttingen and Canada, Pörtner completed his post-doctoral degree (Habilitation) in zoology at the Heinrich Heine University Düsseldorf. After receiving a Heisenberg scholarship from the German Research Foundation (DFG), he pursued research at the Lovelace Medical Foundation in Albuquerque, New Mexico (USA). In 1995 he moved to the Alfred Wegener Institute in Bremerhaven, where he assumed leadership of the Integrative Ecophysiology Research Group, which has since become an independent section, and is still led by him today. His research focuses on the ways in which changes in the marine environment reduce the efficiency and survivability of marine organisms. In this context, Pörtner and his team investigate how ocean warming, ocean acidification and the increasing lack of oxygen are affecting vital biochemical processes in marine life. The researchers analyse the changes in the genome at the cellular level as well as shifts at the species level and within entire ecosystems. Over the past several years, their findings have provided groundbreaking insights into the impact of climate change on marine life, garnering them international acclaim. Hans-Otto Pörtner is now one of the world’s most highly cited academics (Clarivate Analytics), and advises various committees as well as the German Federal Government and the European Commission. Following his contributions as Lead Author and Coordinating Lead Author of the 4th and 5th Assessment Reports of the IPCC (Intergovernmental Panel on Climate Change), in October 2015 he was elected Vice Chair of the IPCC’s Working Group II (Impacts, Adaptation and Vulnerability) for the 6th Assessment Report. He was jointly responsible for the IPCC’s three special reports on 1.5°C, Land and Ocean, and the Cryosphere, and served as Co-Chair of the IPCC’s aforementioned Working Group II for the 6th Assessment Report, which was published in February 2022. Hans-Otto Pörtner is also an elected member of the European Academy of Sciences (EURASC) and a member of the German Advisory Council on Global Change (WBGU).