How do you verify that carbon has been removed?

Ocean habitats vary quite a bit in their ability to capture and store carbon, depending on factors such as geography, geology, and weather patterns. Still, scientists have developed robust methods and best practices to measure and monitor how much blue carbon has been locked away in the plants and soils of mangrove forests, seagrass meadows, and tidal marshes.

For example, we know how quickly different coastal and marine species capture carbon over time, as well as how to measure mangrove forest health. Some smaller blue carbon ecosystem restoration projects make carbon removal estimates based on sites elsewhere with similar species and geology. For larger projects wanting to certify carbon credits or offsets, these need to be verified by an independent authority or nonprofit organization. Groups take measurements before, during, and after project completion to determine the amount of carbon in the soils and vegetation, and that the reduction or removal of emissions is real, measurable, traceable, permanent, beneficial, and independently verified according to globally accepted certification standards such as the Verified Carbon Standard (VCS), the Gold Standard, Plan Vivo, the American Carbon Registry, and/or the Climate Action Reserve.

You can learn how Only One verifies their projects stop carbon emissions on their Projects page.

About the author

Vasiliki I. Chalastani is a PhD candidate at the Laboratory of Harbour Works, National Technical University of Athens (NTUA), Greece. Her thesis, “Optimization Approaches for Marine Spatial Planning,” aims to develop tools for optimal use of the marine environment through reconciliation of human activities and conservation features. Previously, following her undergraduate studies as a civil engineer at NTUA, Chalastani pursued her MSc, “Water Air Pollution and Energy at Global and Regional Scales,” at École Polytechnique, Paris, France. While in France, she has completed an internship at the Laboratoire Océanographique de Villefranche and at École Normale Supérieure on ocean-based solutions. From 2018 to 2019, Chalastani acted as a consultant for the Alternate Minister of Maritime Affairs and Insular Policy of Greece, Nektarios Santorinios. In 2018, she worked for the Institute for Sustainable Development and International Relations (IDDRI), Paris, with Alexandre K. Magnan, on the issue of climate change adaptation. In 2019, Chalastani worked for the Saudi Red Sea Project, developing a preliminary marine spatial planning initiative, under the supervision of Carlos M. Duarte. She is a member of the National Chamber of Engineers and the United Nations Sustainable Development Solutions Network (UN SDSN), Greece.