Blue carbon: Technical review of opportunities for including blue carbon in the Australian Government’s Emissions Reduction Fund

The capacity of blue carbon ecosystems (defined in this report to include mangroves, tidal marshes and seagrasses) to sequester carbon dioxide and mitigate climate change is generating significant interest among scientists and policy makers worldwide. The carbon stored within these blue carbon ecosystems represents nearly 50% of all carbon accumulation in marine sediments, despite occupying just 0.2% of the ocean surface (Duarte et al. 2013b). Australia is home to a substantial area of the world’s blue carbon ecosystems and has also been a focal point of recent scientific advances in understanding the carbon dioxide storage function of these ecosystems (including through the CSIRO Coastal Carbon Cluster  ‐  www.csiro.au/en/Research/OandA/Areas/Coastal‐management/Coastal‐ Carbon‐Cluster). Australia has voluntarily elected to include blue carbon ecosystems in its national greenhouse gas (GHG) accounts. As a consequence, Australia is also considering the development of its domestic policy instruments to reduce national GHG emissions.    These instrumentsinclude potential methods that allow for sequestration and emissions avoidance projects specifically in blue carbon ecosystems.   A pre‐requisite to incorporating Australia’s blue carbon ecosystemsinto the broader framework of the nation’s carbon economy is an assessment of the potential for anthropogenic management activities to sequester carbon (remove additional carbon dioxide carbon, CO2‐C, from the atmosphere) and avoid GHG fluxes (avoiding emission of GHGs expressed as carbon dioxide equivalents, CO2‐e) against a business‐as usual condition. To this end, the objectives of this report were to: 1. Identify the key influencing factors that can alter carbon storage, cycling and emission in Australian mangrove, tidal marsh and seagrass ecosystems. 2. Undertake a detailed assessment of anthropogenic management activities that have the potential to enhance carbon storage or reduce/avoid emissions of GHGs in Australian mangrove, tidal marsh and seagrass ecosystems.   3. Provide recommendations on anthropogenic blue carbon management activities that could be applied and prioritised for potential method development under the Emissions Reduction Fund (ERF). This will include estimation of likely carbon abatement potential (where possible), identification of barriers or constraints to implementation and outlining the steps required to address the identified barriers or constraints.   Influencing Factors For each influencing factor, the mechanisms responsible for altering the magnitude of carbon sequestration or GHG emissions avoidance, existing management practices and legislation within Australian regions and the current and predicted trends have been identified. This has been completed with reference to the current literature, recent findings of the CSIRO Coastal Carbon Cluster and outcomes of a participatory workshop of blue carbon scientists and stakeholders (Section A). Significant knowledge gaps include limited information on the spatial extent over which each influencing factor operates in Australia as well as a lack of research or case studies relevant to Australian blue carbon ecosystems.   Activities Assessment An outcome of the participatory workshop wasthe identification of anthropogenic activities that have the potential to enhance carbon sequestration or reduce/avoid GHG emissions (Section B) from blue carbon ecosystems. The report provides an overall suitability assessment of the identified 10 anthropogenic blue carbon activities that fall within the policy context of the ERF, by comprehensively comparing each against the provided Abatement Integrity Assessment. This task has been completed considering protection and establishment or restoration of mangroves, tidal marshes and seagrasses. Recommended activities In the final section of the report recommendations on the appropriate steps that could be taken toward the inclusion of blue carbon enhancement activities in an ERF method are provided (Section C). This section also identifies potential barriers and/or constraints for those abatement activities and recommends steps that could be taken toward development and implementation of a potential ERF method. It is important to recognise that the work included in this report and the recommendations have been developed considering the existing policy context (as at 2016/17) and that there may be policy shifts (at Federal or State level) which could influence the appropriateness of the recommendations for development of a potential ERF Method. In addition to using research outcomes to underpin potential method development, ERF method development must also consider social, economic and environmental impacts. A summary of each of the recommendations for potential ERF method development follows. The ordering of these recommendations reflects the organisational approach taken in the report and does not imply any prioritisation or assessment of readiness for potential ERF method development.