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Blue Carbon: An Overlooked Resource

By EarthX Stories posted 07-01-2020 13:31


When environmental conversations turn to carbon a lot of attention is paid to both atmospheric carbon in the form of greenhouse gases and terrestrial carbon such as forests. An often overlooked piece of the global carbon puzzle for both carbon sequestration and as an economic tool to be wielded in international voluntary carbon markets is oceanic carbon, also known as blue carbon.

What is blue carbon? According to the National Oceanic and Atmospheric Administration (NOAA), blue carbon is the “the term for carbon captured by the world's ocean and coastal ecosystems.” The world’s oceans and coastal areas have a powerful effect on sequestering greenhouse gases. Coastal sea grasses, mangrove forests and salt marshes all act as carbon sinks by capturing and holding carbon, and actually does so at a faster rate than terrestrial forests. Carbon sequestered in coastal soil can be as old as thousands of years. Conversely, damaging these ecosystems releases large amounts of carbon back into the atmosphere.

During the recently held EarthxOcean Conference 2020, Steven Lutz, Director, Coastal and Oceanic Blue Carbon, GRID-Arendal, Norway + UNEP, described these coastal ecosystem wetlands as some of the most productive on Earth with benefits including protecting shorelines from storms, acting as fish nurseries and habitats, and sequestering carbon. He said even though mangrove forests, sea grass meadows and saltwater marshes only cover less than 2% of the total area of the oceans, they are vitally important for climate change and are extremely threatened ecosystems. Around 35% of the world’s mangrove forests are already gone said Lutz.

Right now there are a number of global blue carbon initiatives, such as the Blue Forests Project, which is part of the United Nation’s Environment Program. The Blue Forests Project seeks to address the challenge of unlocking the value of coastal carbon and ecosystem services through working toward implementing payment for ecosystem services (PES), carbon market schemes, conservation agreements and other mechanisms that help coastal ecosystems.

Examples of this in action include ongoing projects in Ecuador where the government grants local communities the exclusive access to its mangrove resources, particularly a sought-after indigenous crab. Through this project Lutz said the government gets additional eyes on the mangrove forests and community-based conservation while “what the locals get is exclusive access to a lucrative product, and what the world gets is more carbon store in the mangroves.”

Another example is community-based mangrove financing in Kenya which sell mangrove carbon on the global voluntary carbon market for carbon offsets. The profit from these efforts goes toward mangrove conservation and for community projects such as freshwater wells and books for local schools. According to Lutz, this program has already supported increasing the total area of mangrove carbon in the voluntary carbon market by orders of magnitude from just over 100 hectares of mangrove to over 5,000 hectares.

The impact of blue carbon isn’t limited to coastal waters. Interestingly, a key piece in oceanic carbon sequestration is poop. Carbon dioxide is dissolved in the ocean and then consumed by phytoplankton which is in turn eaten by marine life. Carbon sequestration occurs when dead phytoplankton, dead zooplankton and marine life fecal matter sinks to the bottom of the ocean.

“This is important because getting carbon to go as deep as possible is really good for climate change because carbon that is hundreds of meters deep in the ocean can be removed from the atmosphere in far greater timescales than carbon that is associated with the terrestrial ecosystems,” said Lutz.

Carbon in a tree is fixed for hundreds of years, but carbon in deep ocean waters is out of contact with the atmosphere for thousands of years. If those particles reach the bottom of the ocean, they have the chance of entering the geologic record which equates to carbon sequestered on a millennial timescale.

Whales are actually an important element in this process because they store carbon in their bodies and their fecal matter is an important way carbon moves through the oceanic ecosystem. Whale poop found close to the surface becomes a nutrient-rich food for phytoplankton allowing it to grow and store more carbon. And whale bodies themselves become carbon sinks when the animals die and the carbon in their biomass sinks to the bottom of the ocean.

Incredibly, a recent International Monetary Fund study on whales’ contribution to oceanic carbon capture and overall value estimated the value of a single whale in terms of carbon capture and other benefits like whale watching ecotourism was around $2 million per whale and that one while is worth around 1,000 trees in terms of climate change mitigation.

Whether looked at across the open ocean or in coastal wetlands, blue carbon is an all to often overlooked resource for carbon sequestration and valuable resource in the global voluntary carbon market.

Written by:
  David Kirkpatrick


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