Melissa Chierici is co-leader of the work package ‘Human impacts’. Chierici’s present research activity focuses on ocean acidification (OA) and the major drivers of OA in the Arctic. She is a keen field scientist and has also experience with experimental effect studies due to OA. She is leading two major observational research programs aiming to establish time series for the marine carbon cycle in the Arctic to assess causes and trends of OA. More than 20 years expertise within the polar carbon cycle, ocean acidification, sea-ice biogeochemistry, air-sea CO2 exchange, and biogeochemical processes, ocean acidification, and technological and development of marine analytical tools for marine carbon studies, including remote sensing. This has resulted in about 40 peer-review articles, mainly from field studies in polar oceans.