The world’s oceans will likely lose one-sixth of their fish and other marine life by the end of the century if climate change continues its current trajectory, a new study finds. Every degree Celsius that the world’s oceans warm, the total mass of sea animals is projected to drop by 5% according to a comprehensive computer-based study by an international team of marine biologists at the American National Academy of Sciences. The Intergovernmental Panel on Climate Changes special report on global warming already estimates that as of 2017, human activities were responsible for global mean temperature rise of one degree Celsius above preindustrial levels. Unless reductions are made by the world’s leading carbon emitters the world will likely warm by two degrees Celsius above preindustrial levels by 2100.
Under business as usual carbon emissions levels, there could be as much as a 17% loss of biomass in the oceans by 2100. If the world can reduce emissions, losses of biomass can be limited to 5%. The reason for the loss of biomass stems from warmer oceans producing more acidic waters with less oxygen, a less hospitable environment for most marine life. Tropical waters which are already warm are expected to be impacted the most by climate change. Larger species in the ocean, like lobster and wales are also expected to suffer more than the main building blocks of marine life, plankton and bacteria.