Using extended socio-economic scenarios to investigate drivers and pressures on the Baltic Sea up to 2100

Marianne Zandersen1, Kari Hyytiäinen2, Markus Meier4,5, Maciej Tomczak3, Barbara Bauer3, Päivi Haapasaari8,2, Jørgen E. Olesen1, Bo Gustafsson3, Jens Christian Refsgaard9, Erik Fridell5, Sampo Pihlainen2, Martin Le Tissier6 Anna-Kaisa Kosenius2, Detlef Van Vuuren7

 

1 Aarhus University, Denmark

2 University of Helsinki, Finland

3 Stockholm University, Sweden

4 Swedish Meteorological and Hydrological Institute, Sweden

5 Leibniz-Institute for Baltic Sea Research (IOW), Germany

6 Future Earth Coasts, MaREI Centre, Ireland

7 Utrecht University, The Netherlands

8 Aalborg University, Denmark

9 Geological Survey of Denmark and Greenland, Denmark

 

The Baltic Sea is strongly influenced by human activities and the climatic system:

  1. diffuse and point nutrient loads from agriculture, industry and waste water treatment plants have particularly over the past 60 years caused strong eutrophication and large areas of dead sea bottoms in the Baltic Sea, threatening a range of important ecosystem services; and
  2. perhaps increasing runoff integrated over the entire Baltic Sea catchment area in future climate, which in turn accelerates nutrient loads to the sea, while the resilience of the marine ecosystem is weakened due to higher surface water temperatures.

Scenarios that combine socio-economic and climate pathways can be powerful tools to help evaluate the challenges and uncertainties in ecosystem management and the scale of human contributions to regional environmental change under different plausible futures. Such scenarios can be used as input to integrated assessments to investigate how changes in nutrient emissions and subsequent responses in the ecosystem, combined with uncertainty about both future climate impacts and societal developments, may develop and what actions would be needed to obtain good environmental conditions.

Global climate futures, i.e. Representative concentration pathways (RCPs) and socioeconomic futures, i.e. Shared Socioeconomic Pathways (SSPs) were initially developed to address global challenges to mitigate and adapt to climate change. These can also be directly applied as tools when analyzing solutions to regional environmental problems, which would necessitate extending the pathways to regional sectors.

We present a collaborative and interdisciplinary effort to translate global climate and socioeconomic futures into regional drivers and pressures that drive pollution in the Baltic Sea. We propose sectoral narratives of the sustainability pathway (SSP1), the Middle of the Road (SSP2), Regional Rivalry (SSP3) and Fossil Fueled Development (SSP5) along with quantifications of the drivers impacting nutrient loads and the different levels of pressures in terms of total nitrogen and phosphorus loading up to 2100. We combine the SSP/RCP matrix structure with the analytical frame of DPSIR (Drivers, Pressures, State, Impacts and Responses).

Results indicate a plausible range of different responses needed under the different SSPs in order to ensure a good environmental status of the Baltic Sea up to 2100. The approach exemplifies the potential for applying scenario analysis stemming from climate research to regional environmental challenges, which are impacted by climate change.