Abstract
Blue carbon is carbon stored long-term in vegetated coastal ecosystems, which constitutesan important sink for atmospheric carbon dioxide (CO2). However, because methane (CH4)and nitrous oxide (N2O) have higher global warming potentials (GWP) than CO2, theirproduction and release during organic matter diagenesis can affect the climate benefit of bluecarbon. Here, we present a meta-analysis synthesizing seagrass CH4 and N2O fluxes andlong-term organic carbon burial rates, and use these data to estimate the reduced climatebenefit (offsets) of seagrass blue carbon using three upscaling approaches. Mean offsets forindividual seagrass species (34.7% GWP20;1.0% GWP100) and globally (33.4% GWP20;7.0%GWP100) were similar, but GWP20 offsets were higher, and GWP100 offsets were lower thanglobally, for the Australian region (41.3% GWP20;1.1% GWP100). This study highlights theimportance of using long-term organic carbon burial rates and accounting for both CH4 andN2O fluxes in future seagrass blue carbon assessments.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | 374 |
| Tidsskrift | Communications Earth & Environment |
| Vol/bind | 4 |
| Udgave nummer | 1 |
| Antal sider | 9 |
| ISSN | 2662-4435 |
| DOI | |
| Status | Udgivet - dec. 2023 |
Bibliografisk note
Funding Information:We would like to thank Philip Rickenberg for assistance in the field, and four reviewers for comments that improved the manuscript. In particular, we would like to thank one of the reviewers for their detailed comments that helped with determining which studies were long-term organic carbon burial. This project was supported by ARC Grant DP160100248 awarded to B.D.E. and R.N.G. In addition, R.N.G and N.C were supported by grants from the European Research Council grant no 669947(HADES-ERC), Danish National Research Foundation grant no DNRF145 (HADAL) and the Danish National Research Council (FNU7014-00078).