Human impacts and their interactions in the Baltic Sea region

Coastal environments, in particular heavily populatedsemi-enclosed marginal seas and coasts like the Baltic Sea region, arestrongly affected by human activities. A multitude of human impacts,including climate change, affect the different compartments of theenvironment, and these effects interact with each other. As part of theBaltic Earth Assessment Reports (BEAR), we present an inventory anddiscussion of different human-induced factors and processes affecting theenvironment of the Baltic Sea region, and their interrelations. Some arenaturally occurring and modified by human activities (i.e. climate change,coastal processes, hypoxia, acidification, submarine groundwater discharges,marine ecosystems, non-indigenous species, land use and land cover), someare completely human-induced (i.e. agriculture, aquaculture, fisheries,river regulations, offshore wind farms, shipping, chemical contamination,dumped warfare agents, marine litter and microplastics, tourism, and coastalmanagement), and they are all interrelated to different degrees. We presenta general description and analysis of the state of knowledge on theseinterrelations. Our main insight is that climate change has an overarching,integrating impact on all of the other factors and can be interpreted as abackground effect, which has different implications for the other factors.Impacts on the environment and the human sphere can be roughly allocated toanthropogenic drivers such as food production, energy production, transport,industry and economy. The findings from this inventory of availableinformation and analysis of the different factors and their interactions inthe Baltic Sea region can largely be transferred to other comparablemarginal and coastal seas in the world.