This work package deals with contaminants in the earth system as well as and the range of research topics linked to the analyses of sediments, e.g. palaeoclimate, palaeoceanography, geomicrobiology.

Work package 4a. This sub-work package will focus on the transport and dynamics of long-range transported pollutants to the Arctic in the atmosphere, cryosphere, sea, sediment and biota, combining observations, process studies in the field and modelling. Focus will be on hazardous compounds, essential and non-essential elements with strong climate effects. Combined atmospheric-cryospheric-marine transport models will be developed and specific process understanding will be gained through controlled laboratory and field studies.

Work package 4b. This sub-work package will use sedimentary records to among other study changes in past climate in order to improve our understanding of the climate system, its dynamics and consequences for ecosystems and societies in the Arctic. Knowledge of past climate will also be gathered from instrumental data and historical records. The sub-work package also includes the study of present-day biogeochemical activity in sediment records and its regulation at low temperature and composition of organic matter input.