Coastal Blue Carbon

What is Coastal Blue Carbon?

Healthy coastal habitat is not only important for seafood and recreation, it also plays an important role in reducing climate change. Salt marshes, mangroves, and seagrass beds absorb large quantities of the greenhouse gas carbon dioxide from the atmosphere and store it, thus decreasing the effects of global warming. These types of habitat are known as carbon sinks and contain large stores of carbon accumulated over hundreds to thousands of years.

Using more scientific lingo, coastal blue carbon is the carbon captured by living coastal and marine organisms and stored in coastal ecosystems. Salt marshes, mangroves, and seagrass beds play two important roles:

• Carbon sequestration—the process of capturing carbon dioxide from the atmosphere, measured as a rate of carbon uptake per year
• Carbon storage—the long-term confinement of carbon in plant materials or sediment, measured as a total weight of carbon stored

Why is it Important?

Current studies suggest that mangroves and coastal wetlands annually sequester carbon at a rate ten times greater than mature tropical forests. They also store three to five times more carbon per equivalent area than tropical forests. Most coastal blue carbon is stored in the soil, not in above-ground plant materials as with tropical forests. Learn more by listening to this podcast.

Coastal habitats are important for capturing carbon—but their destruction poses a great risk. When these habitats are damaged or destroyed, it is not only their carbon sequestration capacity that is lost. Carbon stored in the habitats is also released, increasing levels of greenhouse gases in the atmosphere. Unfortunately, coastal habitats around the world are being lost at a rapid rate, largely due to coastal development for housing, ports, and commercial facilities.

Figure: Carbon Storage Abilities of Different Habitat Types

Mean long-term rates of C sequestration (g C m−2 yr−1) in soils in terrestrial forests and sediments in vegetated coastal ecosystems. Error bars indicate maximum rates of accumulation. Note the logarithmic scale of the y axis. (Source: Mcleod et al. 2011. A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering C02. Frontiers in Ecology 9(10): 552-560, DOI.)

What is NOAA Doing to Protect “Blue Carbon”?

NOAA is working to advance awareness of coastal blue carbon by:

• Exploring how to incorporate carbon services into existing domestic and international policies, programs, and activities. Considering carbon services (storage, and sequestration) along with other ecosystem services could provide additional incentives for conservation. NOAA is also collaborating with other agencies to support the White House Priority Agenda ) and the inclusion of coastal wetlands into the U.S. National Greenhouse Gas Inventory by 2017.
• Helping to fill the gaps in our understanding of the distribution, magnitude, and rate of coastal habitat carbon services.
• Helping to develop protocols for including coastal carbon services in carbon markets both within the U.S. and internationally. Markets could encourage and produce increased private investment in coastal habitat conservation.  One example is the new Verified Carbon Standard methodology for wetlands. NOAA is working with partners to apply these protocols in the Bringing Wetlands to Market project in Massachusetts. Learn more about this project by listening to this podcast.
• Working with partners, including Restore America’s Estuaries, the Blue Carbon Initiative, and the Global Environmental Fund (GEF) Blue Forest Project, and the Commission for Environmental Cooperation (CEC) to advance blue carbon studies and projects around the world. NOAA has been working with the CEC and partners in Canada and Mexico to complete a North American Blue Carbon Project.