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Duke Research Brings Far-Off Carbon Offset Closer to Home


Duke is supporting the protection of coastal mangroves in Africa to keep carbon from the atmosphere. It was Duke research that helped establish a market for carbon offsets from coastal habitats.
Duke is supporting the protection of coastal mangroves in Africa to keep carbon from the atmosphere. It was Duke research that helped establish a market for carbon offsets from coastal habitats.

Duke University’s continued path to net carbon neutrality by 2024 now includes a Duke research-driven investment in helping preserve coastal habitats more than 4,000 miles from Durham, on the western coast of Africa. 

The university has invested in the protection of carbon-trapping ocean mangroves – wetland shrubs and trees – along the coast of Guinea-Bissau, by supporting an “avoided deforestation” project implemented by the country’s Institute for Biodiversity and Protected Areas (IBAP) with local communities. 

As well as preventing the release of carbon into the atmosphere, the project is contributing to the conservation of globally important biodiversity, and to the long-term economic prosperity of the country’s coastal communities. 

“It’s a small investment for Duke, and Duke’s investment is a small part of the overall effort in Guinea-Bissau,” said Matthew Arsenault, manager of the Duke Carbon Offsets initiative. “But it’s so important for an institution like Duke to be investing in a project like this that is also connected to Duke research.”  

The wetlands support a wealth of biodiversity and are a source of livelihood for nearby residents who use them for agriculture, oyster culture and fishing. Through the purchase of carbon credits generated by this project, Duke is enabling IBAP and local communities to continue to manage these wetlands sustainably, thus keeping the carbon safely in the soil. 

“The investment of Duke and other potential financiers in the framework of this initiative will have global impact in combating the effects of climate change and on the conservation of dry forests, rainforests and the mangrove of the Cacheu National Park and Natural Park of Tarrafes do Rio Cacheu,” said Queba Quecuta, director of Catanhéz National Park. “It will improve the living conditions of the local populations which depend heavily on the goods and services of these ecosystems.” 

Mamadú Camará, the traditional chief of the village of Cadiqui, said the project continues the work his people have been doing for generations. 

“We have traditionally protected our forests forever,” Camará said. “We currently work with IBAP to strengthen the protection and conservation of the ‘Matas de Cantanhéz’ and I agree with this new initiative, which will further encourage the conservation of forests that support the well-being of my community, and from which we extract medicine to treat illnesses, foodstuffs and allows us to have good rain so that we can cultivate our land and have good harvests.” 

Since adopting a climate action plan in 2009, Duke has reduced its own emissions by about 34 percent, mostly through investment in reducing energy emissions and the change in transportation patterns brought about by the pandemic.  

Those reductions will continue over time as existing buildings are made more energy efficient and new, more sustainably designed buildings and other projects come online. Among them is a set of North Carolina solar energy farms in which Duke is a partner that will soon be producing the equivalent of 50 percent of the electricity needed to power campus. 

But the university has also turned to the carbon offsets market to mitigate the carbon it cannot reduce on campus. The offsets market allows investors to buy carbon credits by contributing financially to environmental projects – including conservation efforts – that keep carbon trapped in natural ecosystems and prevent its release into the atmosphere. 

“The university wanted to set an ambitious carbon neutrality goal, to respond to the climate crisis by going above and beyond,” said Tavey Capps, Duke’s sustainability director. “We are being as aggressive as possible on campus with reductions, but we knew that carbon offsets would also have to be a part of meeting that target. The Duke Carbon Offset Initiative was established to ensure that any of the carbon offset projects the university invested in would be of the quality and standard that we set for ourselves.”  

It was Duke research – “Green Payments for Blue Carbon” in 2011 – that helped establish a market for carbon offsets from coastal habitats.   

Brian Murray was lead author on that research while directing the environmental economics program at the university’s Nicholas Institute for Environmental Policy Solutions. Now interim director of the newly-merged Nicholas Institute and Duke’s Energy Initiative, Murray had been working on the carbon market for preserving terrestrial forests when he learned that the carbon-rich peat soil in coastal wetlands hold more carbon than forests on land. =

Peat soil is the largest natural carbon store, and more and deeper layers of sediment build up in wetland environments.  

“There’s more carbon per hectare, so you get a bigger bang for the buck,” Murray said. 

Investors can also establish new mangroves, Murray said. “But protecting existing ones has much greater biophysical and economic potential, because the carbon’s already there and you’re avoid releasing that into the atmosphere,” he said. 

John Virdin, director of the ocean and coastal policy program at the Nicholas Institute, tipped off the university about the Guinea-Bissau project, which he worked on while with the World Bank before coming to Duke. Virdin also coauthored a 2020 report from the Nicholas Institute assessing the feasibility of creating carbon offsets to protect mangroves elsewhere in western Africa. 

Mangroves in several of Guinea-Bissau’s neighbors have been lost to lucrative shrimp fishing and other coastal development. Building upon work by the local office of the International Union for Conservation of Nature and other leaders in the country, the Government of Guinea Bissau with support from the World Bank and other donors, established a national parks and protected areas system which now covers 26 percent of the country. In parallel with this, a social fund was launched to help park residents build schools and other infrastructure, and to adopt sustainable livelihood technologies in what Virdin called a “parks for people” approach. 

“Innovative projects like these are a high priority for the World Bank, as they not only address the immediate needs of people but also promote green and inclusive growth over the long-term,” said Tanya Yudelman, natural resource management and environmental specialist for the World Bank.

Assuring the long-term future of this national parks system requires more investment. The World Bank realized, through the work of Murray and others, that IBAP could sell carbon offsets for the mangroves the parks are preserving. The avoided deforestation project was designed to support this approach and is being implemented in partnership with the BioGuinea Foundation, a conservation trust fund established to help secure the park system’s long-term sustainability. It’s hoped Duke being one of the early buyers will spur other institutions to get involved. 

“For the BioGuinea Foundation, Duke’s participation is such a strong signal for others to join the effort for the visibility and viability of this project,” said Fenosoa Andriamahenina, executive secretary of the BioGuinea Foundation. 

Guinea-Bissau isn’t the only overseas project from which Duke has bought offsets. Another is a community carbon market protecting forests in Oaxaca, Mexico. But the bulk of the investment has been in the Carolinas, from urban forestry and turning swine waste to energy in North Carolina to a new project in South Carolina that will help rural homes become eligible for energy efficiency upgrades. 

The Guinea-Bissau project provides only 2,000 of the approximately 80,000 credits Duke estimates it will need to reach carbon neutrality. Each credit represents one metric ton of carbon dioxide emissions. The university currently has about 15,000 credits total and remains on track to meet its goal by 2024, Arsenault said. 

“We are currently deciding which specific projects will make up the rest of that estimated 80,000,” he said. The Guinea-Bissau investment is a model for the projects Duke is looking to invest in. 

“Protected areas in Guinea-Bissau are co-managed with the human communities living in and around them,” said Justino Biai, IBAP director. “The ecological, social and above all economic benefits should primarily accrue to these communities. Projects of this nature and partners such as Duke are critical to fulfilling these goals and helping to safeguard local, national and planetary interests.”

Learn more about Duke's Climate Commitment at