The MOSES project comprises four different so-called “event chains”: Heat waves, hydrologic extremes, ocean eddies and the thawing of permafrost which were chosen because of their relevance to climate and environmental change and their pronounced ecological, social and economic impacts. These impacts potentially have tremendous ecological and socioeconomic consequences for many European countries (heat waves, hydrologic extremes) or have significant global implications (permafrost, ocean eddies). The investigation of such events is most acute as the impact of global change on society becomes increasingly evident. Because the calculation of future climate change scenarios and the planning of adequate protection measures relies on a much improved understanding of the complex interactions across multiple scales and compartments, the implementation of such an enhanced modular observation system, including a novel transdisciplinary research approach that integrates the different Earth science disciplines, is more than overdue. This implementation can be facilitated by the centres that are part of the “Earth and Environment” research area. The Helmholtz Centres utilize scientific and technical expertise to realize such comprehensive campaigns, and they can build upon excellently equipped observatories to target these four event chains.