PLEA Network

1 August 2016, Carbon Brief, Guest post: An Antarctic voyage in search of blue carbon. A guest article from Dr David Barnes, a marine benthic ecologist at the British Antarctic Survey, and colleagues Chester Sands, Narissa Bax, Rachel Downey, Christoph Held, Oliver Hogg, Kirill Minin, Camille Moreau, Bernabé Moreno and Maria Lund Paulsen from the Antarctic Seabed Carbon Capture Change project. As global temperatures rise, the response from different parts of the climate system can amplify or dampen the pace of warming. These are known as feedback loops. Melting sea ice, for example, tends to cause a positive feedback loop. The loss of sea ice means that energy from the sun that would have been reflected away by the bright white ice is instead absorbed by the darker ocean. This causes further warming, which in turn causes more sea ice loss, and so on. Negative feedback loops, on the other hand, work to reduce further warming. Blue carbon is one such example. Blue carbon is the term given to carbon stored in coastal or marine ecosystems. It typically refers to salt marshes, mangroves, and seagrass beds, which capture CO2 from the atmosphere and store it in their leaves, stems and in the soil. A less well-known – but no less important – contribution to blue carbon comes from tiny organisms that live on the seabed. These creatures, known as zoobenthos, take up carbon from the plankton they eat and the CO2 in seawater they use to build their skeletons. When the zoobenthos die, their bodies are eventually buried in the sediment of the seabed, sequestering carbon in the process. Our initial research suggests that coastal areas of the Arctic and Antarctic are absorbing and storing more blue carbon as the climate warms. This boost to carbon storage could form one of the biggest negative feedback loops against climate change on Earth. Read More here