What is Blue Carbon?
- Trésor Daniel Mefire
- Oct 1, 2024
- 6 min read
Updated: Oct 6, 2024
September 30, 2024
Author: Trésor Daniel MEFIRE
Country: Cameroon
Photo credit: dailyscience.be/Website
SUMMARY
Blue carbon refers to the carbon stored in coastal and marine ecosystems, particularly mangroves, salt marshes, and seagrasses. These ecosystems are vital for mitigating climate change, as they sequester significant amounts of carbon dioxide (CO2) from the atmosphere. Globally, blue carbon ecosystems cover about 49 million hectares and are rapidly declining, with an estimated loss of 340,000 to 980,000 hectares each year. The primary threats to these ecosystems include coastal development, agricultural expansion, climate change, and pollution.
The decline of blue carbon habitats results in increased greenhouse gas emissions, loss of biodiversity, and adverse impacts on coastal communities that rely on these ecosystems for their livelihoods. To combat these threats, solutions such as legal protection, restoration projects, sustainable management practices, community engagement, and ongoing research are essential. Protecting and restoring blue carbon ecosystems is crucial for climate change mitigation and supporting biodiversity while ensuring the sustainability of coastal communities
BACKGROUND
What is Blue Carbon?
Introduction
Blue carbon refers to the carbon captured by coastal and marine ecosystems, particularly mangroves, salt marshes, and seagrasses. These ecosystems play a crucial role in mitigating climate change by sequestering carbon dioxide (CO2) from the atmosphere and storing it in biomass and sediments. However, blue carbon ecosystems are facing significant threats that endanger their ability to function as effective carbon sinks. Blue carbon ecosystems store more carbon per unit area than terrestrial forest, making them a bold weapon in our battle against climate change.
I. State of Blue Carbon
Blue carbon ecosystems cover approximately 49 million hectares globally and are estimated to store between 10,450 and 25,070 million tons of CO2 in the top meter of sediment (International Blue Carbon Initiative, 2020; Pendleton et al., 2012). Mangroves alone can store between 917 and 1,028 tons of carbon per hectare, while salt marshes store approximately 512 tons per hectare (Beers et al., 2020). These ecosystems are highly effective at sequestering carbon, with burial rates up to 55 times faster than tropical rainforests (McLeod et al., 2011).
Despite their importance, blue carbon ecosystems are rapidly declining. It is estimated that between 340,000 and 980,000 hectares of blue carbon ecosystems are lost each year (Traace, 2024). Since the 1940s, up to 90% of mangroves have disappeared in Southeast Asia alone (Wetlands International, 2021). The degradation of these habitats not only reduces their capacity to sequester carbon but also threatens biodiversity and the livelihoods of communities that depend on these ecosystems.
II. Threats to Blue Carbon
The primary threats to blue carbon ecosystems include:
Coastal Development: Urbanization and infrastructure development often lead to the destruction of mangroves and salt marshes for housing, tourism, and industrial activities. This development results in habitat loss and fragmentation.
Agricultural Expansion: Intensive agricultural practices can lead to the drainage of wetlands and conversion of coastal areas into farmland. This not only destroys habitats but also disrupts natural water flow.
Climate Change: Rising sea levels and increased temperatures pose significant risks to blue carbon ecosystems. Higher salinity levels can affect plant growth in mangroves and salt marshes, while ocean acidification impacts seagrass health (FAO, 2020).
Pollution: Runoff from agricultural lands introduces fertilizers and pesticides into coastal waters, leading to eutrophication. This process can cause harmful algal blooms that suffocate seagrasses and disrupt marine life.
According to a report by The Ocean Foundation (2021), approximately 30% of blue carbon habitats have been lost globally due to these combined pressures.
III. Consequences of Threats on Blue Carbon
The decline of blue carbon ecosystems has several serious consequences:
Increased Greenhouse Gas Emissions: When blue carbon habitats are destroyed or degraded, the stored carbon is released back into the atmosphere as CO2, contributing significantly to global warming. It is estimated that emissions from the loss of these ecosystems account for nearly 20% of global emissions due to deforestation (Pendelton et al., 2012). And a study by the United Nations Environment Programme (UNEP) (2018) found that mangrove deforestation in Africa contributed to approximately 10% of the continent's total greenhouse gas emissions.
Loss of Biodiversity: Blue carbon ecosystems support a wide range of species. The destruction of these habitats leads to habitat loss for numerous marine organisms, resulting in decreased biodiversity. According to Wetlands International (2021), over 50% of global mangrove forests have been lost in the past 50 years. And the World Conservation Union (IUCN) (2020) estimates that over 70% of mangrove forests in Cameroon have been lost in the past 50 years. This has led to a significant decline in biodiversity, including threatened species like the manatee and the red-collared douc langur.
Impact on Coastal Communities: Many coastal communities rely on blue carbon ecosystems for their livelihoods through fishing, tourism, and natural resources. The degradation of these habitats can lead to economic instability and food insecurity. A study by the Cameroonian Ministry of Environment, Nature Protection and Sustainable Development y (MINEPDED) (2021) found that coastal communities in Cameroon reliant on fishing experienced a 25% decline in income due to the degradation of mangrove forests.
Increased Vulnerability to Climate Impacts: Healthy blue carbon ecosystems provide natural protection against storm surges and coastal erosion. Their loss increases vulnerability for coastal communities facing extreme weather events exacerbated by climate change (FAO, 2020). A report by the Intergovernmental Panel on Climate Change (IPCC) (2019) states that coastal communities in West Africa protected by mangroves experienced up to 50% less damage from hurricanes and tsunamis compared to unprotected areas.
IV. Solutions to Threats on Blue Carbon
To address the threats facing blue carbon ecosystems, several solutions can be implemented:
Legal Protection: Strengthening laws and regulations aimed at protecting blue carbon habitats is essential. This includes designating marine protected areas (MPAs) that safeguard critical ecosystems from development and degradation. A study by the Nature Conservancy (2023) found that countries with strong legal protections for blue carbon habitats have experienced a 50% lower rate of mangrove loss compared to those without. The Cameroonian government has implemented several legal measures to protect its coastal ecosystems, including the Marine Protected Areas Act of 2016. However, enforcement remains a challenge.
Restoration Projects: Initiatives aimed at restoring degraded blue carbon habitats can help recover their ecological functions. This includes replanting mangroves and restoring salt marshes through community-based projects. A meta-analysis by Donato et al. (2014) showed that restored mangrove forests can sequester carbon at rates comparable to old-growth forests. The NGO Conservation International has successfully restored over 100 hectares of mangrove forests in Cameroon through community-based reforestation initiatives.
Sustainable Management Practices: Promoting sustainable agricultural practices that minimize runoff and protect coastal areas can help maintain healthy blue carbon ecosystems. The Food and Agriculture Organization (FAO) (2020) reports that implementing sustainable aquaculture practices can reduce nutrient pollution and protect coastal ecosystems by up to 70%.
Community Engagement: Involving local communities in conservation efforts ensures that restoration projects are culturally appropriate and economically viable. Education programs about the importance of blue carbon can foster community stewardship. A report by the World Wild Fund (WWF) (2022) found that community-based conservation initiatives for seagrass meadows led to a 25% increase in local fish catches.
Research and Monitoring: Continued research on blue carbon ecosystems is necessary to understand their dynamics better and develop effective management strategies (Ocean Foundation, 2021).
Conclusion
Blue carbon ecosystems are critical for mitigating climate change, supporting biodiversity, and sustaining coastal communities. However, they face significant threats that require immediate action for their protection and restoration. By implementing effective policies, engaging local communities, and promoting sustainable practices, we can preserve these vital ecosystems for future generations.
REFERENCES
Beers, L., Crooks, S., & Fennessy, S. (2020). Desktop study of blue carbon ecosystems in Ramsar Sites. Silvestrum Climate Associates. Retrieved from Ramsar
FAO. (2020). The Role of Blue Carbon Ecosystems in Climate Change Mitigation. Food and Agriculture Organization. Retrieved from FAO
International Blue Carbon Initiative. (2020). Global Estimates of Blue Carbon Ecosystems. Retrieved from Blue Carbon Initiative
McLeod, E., Chmura, G. L., Coburn, A., Duarte, C. M., & Lovelock, C. E. (2011). A blueprint for blue carbon: toward the development of a role for coastal habitats in a global carbon market. Environmental Science & Policy, 14(3), 1-10. DOI:10.1016/j.envsci.2010.12.001
Pendleton, L., Donato, D. C., Murray, B. C., Crooks, S., & Pritchard, E. (2012). Estimating global blue carbon emissions from conversion and degradation of coastal ecosystems. PLOS ONE, 7(9), e43542. DOI:10.1371/journal.pone.0043542
Traace. (2024). The Essential Role of Blue Carbon. Retrieved from Traace
Wetlands International. (2021). The Importance of Wetlands for Climate Change Mitigation. Retrieved from Wetlands International
The Ocean Foundation. (2021). Blue Carbon: A Critical Ecosystem Service. Retrieved from Ocean Foundation
IPCC. (2019). Special Report on the Ocean and Cryosphere in a Changing Climate. Intergovernmental Panel on Climate Change.
Nature Conservancy. (2023). Legal Protection for Blue Carbon Ecosystems. Retrieved from Nature Conservancy
World Wildlife Fund (WWF). (2022). Community Engagement in Seagrass Conservation: Enhancing Local Stewardship and Fisheries. Retrieved from WWF.
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