Ocean Ecosystems: A Primer

The ocean helps fight climate change because it acts as a nature-based solution. It soaks up and has stored about 30% of the carbon dioxide that humans have put into the atmosphere (NOAA), and over 90% of the extra heat from greenhouse gases (NOAA). The ocean covers most of our planet (71%), hence a healthy ocean and its ecosystems have the capacity to do much more.

Carbon dioxide is a gas that causes global warming when the gas comes from burning fossil fuels as well as cutting down trees. However, carbon dioxide also occurs naturally. The element carbon is in all living things. Both land and ocean plants constantly move carbon around through natural processes.

·       During photosynthesis, plants take in carbon dioxide from the air to grow their roots and leaves.

·       Animals eating plants help spread carbon around the environment.

·       When plants die, their remains usually get buried in the soil.

·       Undisturbed, this carbon can stay buried for hundreds of years or more.

"Blue Carbon" is a term used for carbon dioxide removed from the atmosphere and stored for centuries in coastal ocean ecosystems by superpower aquatic trees and plants like mangroves, seaweeds, and seagrasses (*2021 IPCC Report). “Blue” refers to wet, ocean, and aquatic plants, while “green” refers to land-based plants.

·       These "blue carbon" ocean ecosystems can capture carbon much faster than land-based “green” ecosystems.

·       They store a lot more carbon per area because their soil is underwater and doesn't have much oxygen.

·       Many plants in these blue environments grow fast and have roots that store carbon. For example, mangrove trees, which grow in warm places like Miami.

However, human activities like urban development, agricultural pollution, and altered water flow can damage these blue carbon ecosystems. When these systems are harmed or flooded, they can worsen global warming by releasing carbon back into the atmosphere. This is why it's so important to preserve and protect the ocean environment.

* IPCC, 2021: In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 2215–2256, doi:10.1017/9781009157896.022.