Our Impact: First Comprehensive Estimate of Blue Carbon Losses Drives Policy

This is the ninth installment in a 12-part series highlighting the environmental policy impacts of the Nicholas Institute for Energy, Environment & Sustainability over its first decade.

When a Nicholas Institute for Energy, Environment & Sustainability-led study provided the first comprehensive estimates of global carbon dioxide emissions from the loss of coastal marine ecosystems, the world was alerted to a serious climate change threat: those emissions—as much as 1 billion tons of carbon dioxide equivalent per year—were potentially 10 times greater than previously thought and rivaled total national emissions from some developed countries.

The research, published in September 2012 in the journal PLOS ONE, highlighted the potential value of keeping in place so-called blue carbon—the carbon stored in the sediment below mangroves, sea grasses, and salt marshes. Rather than focusing on quantifying carbon amounts in various ecosystems—as other studies to date had done—it examined what happens when these ecosystems are disturbed and stored carbon is released and whether protocols and methodologies could be implemented to offset carbon emissions.

“Coastal ecosystems are a tiny ribbon of land, only 6 percent of the land area covered by tropical forest, but the emissions from their destruction are nearly one-fifth of those attributed to deforestation worldwide,” said Linwood Pendleton, the study’s lead author and now a senior scholar with the Nicholas Institute’s Ocean and Coastal Policy Program. “One hectare, or roughly two acres of coastal marsh, can contain the same amount of carbon as 488 cars produce in a year. Comparatively, destroying a hectare of mangroves could produce as much greenhouse gas emissions as cutting down three to five hectares of tropical forest.”

Blue carbon had received little notice when the Nicholas Institute first proposed payments for blue carbon protection in a 2010 policy brief. In it, the Nicholas Institute’s Environmental Economics Program director Brian Murray, Pendleton, and their co-authors suggested that coastal ecosystems could be an ideal target for carbon financing, while calling attention to the need for much more accurate estimates of carbon sequestration and emissions rates to better understand the economic viability of blue carbon protection—the very need that they later helped address with the PLOS ONE study.

Even before they began work on that study, Murray and Pendleton were addressing coastal habitat preservation as members of the International Blue Carbon Policy Working Group. The group’s initial work on a strategy to integrate mangrove, sea grass, and salt marsh preservation into biodiversity policies and global warming mitigation strategies was cataloged in Blue Carbon Policy Framework. A Nicholas Institute policy brief, published the same month as the PLOS ONE study, examined the evolution of blue carbon in the United Nations Framework Convention on Climate Change’s (UNFCCC) process.

To preserve coastal habitats’ carbon sequestration and other ecosystem services, including storm buffering, pollutant filtering, and fisheries support, the PLOS ONE study authors pointed to the UNFCCC’s Reducing Emissions from Deforestation and Forest Degradation (REDD+) initiative. They suggested that assignment of credits to carbon stored in coastal habitats through analogous international climate change mitigation programs might stem blue carbon losses.

“The article increased confidence in the technical and scientific underpinning of the blue carbon concept,” said study co-author Dorothee Herr of the International Union for Conservation of Nature (IUCN) Global Marine Program. “It was important to quantify the emissions from mismanagement of coastal ecosystems to get broad attention to this topic and to be able to develop appropriate policy and other responses.”

The study has helped advance those goals. Its results were cited in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report, released in 2013, and have been used to develop long-term coastal habitat conservation policy options under the United Nations climate change agreement.

“The two biggest hurdles for blue carbon activities to access carbon markets are uncertainty about whether policies will be enacted to create markets of global scale and breadth and whether such markets will accept blue carbon as a creditable activity,” said Tibor Vegh, Nicholas Institute policy associate. “The former issue may be somewhat clarified by developments at the 21st session of the Conference of the Parties to the UNFCCC in November and December 2015. The latter will depend on development of methodologies to credibly measure, report, and verify greenhouse gas emissions from coastal ecosystems.”

He adds that both these hurdles may be lowered to the extent that blue carbon activity can be tied to REDD+—an opportunity the Nicholas Institute began to examine as early as 2011 in a report suggesting that the possibilities for blue carbon financing mirror those that have emerged for forest-stored carbon in discussions of REDD+ financing, if at a different scale—and that it continues to explore.

As part of a study performed in cooperation with GRID-Arendal for the United Nations Environment Programme, the Nicholas Institute is working with Duke University’s Marine Geospatial Analysis Lab to explore financing mechanisms for the restoration and conservation of coastal ecosystems in west Africa. Specifically, they are researching the region’s blue carbon economic and financial potential according to the literature and investigating REDD+ and other global blue carbon crediting activities related to west African mangroves. They are also examining existing policy frameworks for blue carbon and ongoing and completed blue carbon-related activities in the region.


--Story by Melissa Edeburn