Baltic Sea at Risk of Becoming Carbon Emission Source Due to Climate Change

Research indicates the Baltic Sea may soon shift from carbon sink to emission source due to climate change.

Key Points

  • • The Baltic Sea's status as a carbon sink is threatened by climate change and nutrient pollution.
  • • Summer algal blooms absorb significant carbon, but winter decay reverses this effect.
  • • Current research on Askö Island aims to assess temperature impacts on carbon absorption.
  • • Final insights on emissions from the Baltic Sea will take years to fully understand.

Recent research highlights a concerning trend regarding the Baltic Sea: it may transition from a carbon sink to a source of greenhouse gas emissions as climate change progresses alongside nutrient pollution. Johan Eklund, a marine ecology professor at Stockholm University, emphasizes the urgent need to investigate how the Baltic Sea will respond to these environmental changes. The sea, which is already one of the most affected oceans globally due to warming, is currently showing near-zero net absorption of greenhouse gases.

A significant aspect of this shift involves seasonal algal growth, which absorbs up to 2.5 million tons of carbon monthly during summer months, as noted by Anna Rutgersson, a meteorology professor at Uppsala University. However, this carbon is largely released back into the atmosphere during winter as decay occurs, complicating the Baltic Sea's overall carbon footprint. Both Eklund and Rutgersson point out that the interplay of higher temperatures, nutrient overloading, and overfishing further complicates predictions on the sea's future emissions.

Research on Askö Island is currently underway to determine how rising temperatures affect the Baltic's ability to serve as a carbon sink. Preliminary results from this project are expected in the fall of this year, while comprehensive findings may take several years to finalize, leaving experts and stakeholders anxious about the future implications for climate change in the region.