Future projections of record-breaking sea surface temperature and cyanobacteria bloom events in the Baltic Sea

Ambio. 2019 Nov;48(11):1362-1376. doi: 10.1007/s13280-019-01235-5. Epub 2019 Sep 10.


Aiming to inform both marine management and the public, coupled environmental-climate scenario simulations for the future Baltic Sea are analyzed. The projections are performed under two greenhouse gas concentration scenarios (medium and high-end) and three nutrient load scenarios spanning the range of plausible socio-economic pathways. Assuming an optimistic scenario with perfect implementation of the Baltic Sea Action Plan (BSAP), the projections suggest that the achievement of Good Environmental Status will take at least a few more decades. However, for the perception of the attractiveness of beach recreational sites, extreme events such as tropical nights, record-breaking sea surface temperature (SST), and cyanobacteria blooms may be more important than mean ecosystem indicators. Our projections suggest that the incidence of record-breaking summer SSTs will increase significantly. Under the BSAP, record-breaking cyanobacteria blooms will no longer occur in the future, but may reappear at the end of the century in a business-as-usual nutrient load scenario.

Keywords: Climate change; Coastal seas; Cyanobacteria; Extremes; Numerical modeling; Sea surface temperature.

MeSH terms

  • Baltic States
  • Climate Change
  • Cyanobacteria*
  • Ecosystem*
  • Oceans and Seas
  • Temperature