Professor Andreas Oschlies is Head of the Biogeochemical Modelling research unit at GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany. Prof. Oschlies develops and uses numerical and mechanistic ecological and biogeochemical models to understand constraints on oceanic carbon uptake and the sensitivity of this carbon sink to climate. He is currently heavily involved in assessing climate engineering proposal and is co-ordinator of two large-scale research projects: Climate Engineering: Risk, Challenges, Opportunities and the Collaborative Research Centre 754 Climate-Biogeochemistry Interactions in the Tropical Ocean.