Blue carbon – a nature-based solution
Blue carbon is the organic carbon sequestered in vegetated coastal ecosystems, especially mangroves, seagrass and tidal marshes. These plants fix carbon through photosynthesis which is then stored in their biomass and the soil in which they grow.
On average, they sequester more carbon per unit area than in terrestrial forests and so are a potentially valuable tool in climate change mitigation through ‘Nature-based Solutions’.
Along with their high carbon sequestration rates, they also provide protection from damaging storm waves and surges, and supply food and habitat for numerous species including many that are the basis of recreational and commercial fisheries. These ecosystems underpin livelihoods in coastal areas of many countries.
The greatest extent of mangroves and seagrasses occurs across the Indo-Pacific region, notably in Indonesia, Malaysia, Papua New Guinea and Australia.
Coastal blue carbon ecosystems are declining worldwide due to unsustainable coastal development. These losses not only prevents their ability to sequester carbon but can cause release of stored carbon back into the atmosphere.
Blue carbon in Australia and the Indo-Pacific
Australia stands to beneﬁt from protecting and restoring blue carbon ecosystems. Restoration of the historical extent of blue carbon ecosystems, together with protection of threatened coastal ecosystems, could help mitigate Australia's greenhouse gas emissions while enhancing the other benefits that these ecosystems provide.
We are working with BHP to measure and quantify the net emission reduction potential of Australia's mangroves, seagrasses and tidal marshes, as well as measuring the value of other co-benefits. This work will help provide the information needed to accelerate the development and adoption of blue carbon restoration in Australia.
In 2012 – 2015, CSIRO collaborated with several universities as part of the CSIRO carbon cluster to provide the largest initiative undertaken in Australia to quantify the climate mitigation potential of blue carbon and understand the factors affecting carbon storage and sequestration. The carbon cluster led to a technical review [pdf · 2.6mb] which outlined potential methods for the Emission Reduction Fund (ERF).
Supporting the Indo Pacific
Our work in blue carbon ecosystem science is aligned to our focus on development of a sustainable blue economy, nature-based solutions and low carbon development and continues our history of collaborating in this area.
CSIRO is providing science, generating knowledge exchange, and building capacity in the Indo-Pacific to help enable the countries in the region to harness the climate change mitigation opportunities these ecosystems provide.
Our activities include:
- In collaboration with IORA, we are building knowledge and capacity in the protection and restoration of blue carbon ecosystems throughout the Indian Ocean region via the IORA Blue Carbon Hub. The hub seeks to support IORA Member States which collectively contain a large proportion of the world’s mangrove and seagrass carbon.
- We are working with Sri Lanka to increase capacity and restore the mangrove forests lost from decades of coastal development, including unsustainable aquaculture practices. This helps support Sri Lanka’s role as Champion of the Commonwealth Mangrove Ecosystems and Livelihoods Action group.
- CSIRO are supporting Pacific Island countries by strengthening their capacity to integrate blue carbon into their national greenhouse gas inventories and climate policy. For example, assistance to Fiji and Papua New Guinea through mapping of blue carbon ecosystems and measurement of carbon samples will enhance capacity to include blue carbon in national greenhouse gas inventory, and occurs alongside case studies of how livelihoods depend on these ecosystems.
- CSIRO is supporting partners in Indonesia to map seagrass ecosystems and measure the carbon in seagrass soils to help Indonesia understand and manage its seagrass resources. In parallel, we work with partners to understand how livelihoods of villagers in coastal villages of Sumbawa, Sulawesi and Flores rely on blue carbon ecosystems.