scholarly journals The blue carbon wealth of nations

Author(s):  
Christine Bertram ◽  
Martin Quaas ◽  
Thorsten B. H. Reusch ◽  
Athanasios T. Vafeidis ◽  
Claudia Wolff ◽  
...  

AbstractCarbon sequestration and storage in mangroves, salt marshes and seagrass meadows is an essential coastal ‘blue carbon’ ecosystem service for climate change mitigation. Here we offer a comprehensive, global and spatially explicit economic assessment of carbon sequestration and storage in three coastal ecosystem types at the global and national levels. We propose a new approach based on the country-specific social cost of carbon that allows us to calculate each country’s contribution to, and redistribution of, global blue carbon wealth. Globally, coastal ecosystems contribute a mean ± s.e.m. of US$190.67 ± 30 bn yr−1 to blue carbon wealth. The three countries generating the largest positive net blue wealth contribution for other countries are Australia, Indonesia and Cuba, with Australia alone generating a positive net benefit of US$22.8 ± 3.8 bn yr−1 for the rest of the world through coastal ecosystem carbon sequestration and storage in its territory.

2017 ◽  
Vol 599-600 ◽  
pp. 1479-1484 ◽  
Author(s):  
Songlin Liu ◽  
Zhijian Jiang ◽  
Jingping Zhang ◽  
Yunchao Wu ◽  
Xiaoping Huang ◽  
...  

2021 ◽  
Author(s):  
John Barry Gallagher ◽  
Vishnu Prahalad ◽  
John Aalders

Abstract Total organic carbon (TOC) sediment stocks as a CO2 mitigation service require exclusion of allochthonous black (BC) and particulate inorganic carbon corrected for water–atmospheric equilibrium (PICeq). For the first time, we address this bias for a temperate salt marsh and a coastal tropical seagrass in BC hotspots that represent two different blue carbon ecosystems of Malaysia and Australia. Seagrass TOC stocks were similar to the salt marshes with soil depths < 1 m (59.3 ± 11.3 and 74.9 ± 18.9 MgC ha− 1, CI 95% respectively). Both ecosystems showed larger BC constraints than their pristine counterparts did. However, the seagrass meadows’ mitigation services were largely constrained by both higher BC/TOC and PICeq/TOC fractions (38.0% ± 6.6% and 43.4% ± 5.9%, CI 95%) and salt marshes around a third (22% ± 10.2% and 6.0% ± 3.1% CI 95%). The results provide useful data from underrepresented regions, and, reiterates the need to consider both BC and PIC for more reliable blue carbon mitigation assessments.


2021 ◽  
Author(s):  
Matteo Meli ◽  
Luigi Bruno

&lt;p&gt;Changes in land use represent, after fossil-fuel combustion, the greatest cause of greenhouse-gases emission into the atmosphere. Coastal wetlands, also referred as coastal blue carbon ecosystems (e.g. salt marshes, mangrove forests, seagrass meadows, swamps), represent one of the most powerful C sinks among the Earth&amp;#8217;s ecosystems, being capable to sequester organic carbon (OC) at rates ca. 30-50 times higher than terrestrial forests. Historically, land reclamation for agriculture, farming and urban expansion, severely impacted coastal wetlands, causing their loss and degradation. Wetlands drainage lead to the oxidation of organic matter previously stored under anaerobic conditions and the release of CO&lt;sub&gt;2&lt;/sub&gt; into the atmosphere. Only recently the critical role of blue carbon ecosystems in climate-change mitigation has been recognised, highlighting the importance of protecting and studying these precious environments.&lt;/p&gt;&lt;p&gt;In this work, changes in land use in the last two centuries are reconstructed through comparison with historical maps. At the beginning of the 19&lt;sup&gt;th&lt;/sup&gt; century Napoleon Bonaparte requested the development of high-quality maps of occupied territories. Among these, the so-called &amp;#8216;Carta del Ferrarese&amp;#8217; (CdF), completed between 1812 and 1814, is composed of 38 sheets and represents, to a scale of 1:15.000, 240.000 hectares of the Po lowlands, roughly corresponding to the present-day Ferrara district. The CdF, archived at the Kriegsarchiv in Vienna, is an extraordinary example among historical maps for its high quality and accuracy, which constitute a two-centuries-old reliable paleo-landscape picture.&lt;/p&gt;&lt;p&gt;Within the Historical Land Use Change research project, leaded by the Emilia-Romagna Statistical and GIS Service, the CdF was scanned, accurately georeferenced and orthorectified, showing a surprising generalized match with recent maps. More than 31.000 polygons were digitized in a GIS environment and interpreted on the basis of the European Corine Land Cover codes, properly modified for the land uses at the time.&lt;/p&gt;&lt;p&gt;Comparison with the recent land use analysis, carried out in 2014, highlights changes in land use, mainly related to land reclamation. Salt marshes and swamps, originally extended for 100.000 hectares, were reduced of about 85%, starting from 1861. Major phases of land reclamation occurred in 1870s and 1960s. Geochemical analyses on shallow samples (depth &lt; 50 cm), depict OC content of artificially drained soils &lt; 5% of the total volume. Soil texture testifies to the almost complete mineralization of OC after reclamation. Only recently drained soils show higher OC content, in the range of 10-15%.&lt;/p&gt;


2017 ◽  
Vol 60 (5) ◽  
pp. 809-820 ◽  
Author(s):  
Yao Zhang ◽  
MeiXun Zhao ◽  
Qiu Cui ◽  
Wei Fan ◽  
JiaGuo Qi ◽  
...  

2020 ◽  
Vol 12 (1) ◽  
pp. 469-497 ◽  
Author(s):  
Simon M. Cragg ◽  
Daniel A. Friess ◽  
Lucy G. Gillis ◽  
Stacey M. Trevathan-Tackett ◽  
Oliver M. Terrett ◽  
...  

More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems—salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose—an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.


2021 ◽  
Vol 18 (16) ◽  
pp. 4717-4732
Author(s):  
Melissa A. Ward ◽  
Tessa M. Hill ◽  
Chelsey Souza ◽  
Tessa Filipczyk ◽  
Aurora M. Ricart ◽  
...  

Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon stocks, sources, and exchanges in seagrass meadows, salt marshes, and unvegetated sediments in six bays along the California coast. In the top 20 cm of sediment, the salt marshes contained approximately twice as much OC as seagrass meadows did, 4.92 ± 0.36 kg OC m−2 compared to 2.20 ± 0.24 kg OC m−2, respectively. Both salt marsh and seagrass sediment carbon stocks were higher than previous estimates from this region but lower than global and US-wide averages, respectively. Seagrass-derived carbon was deposited annually into adjacent marshes during fall seagrass senescence. However, isotope mixing models estimate that negligible amounts of this seagrass material were ultimately buried in underlying sediment. Rather, the vast majority of OC in sediment across sites was likely derived from planktonic/benthic diatoms and/or C3 salt marsh plants.


2020 ◽  
Author(s):  
John Barry Gallagher ◽  
Vishnu Prahalad ◽  
John Aalders

AbstractTotal organic carbon (TOC) sediment stocks as a CO2 mitigation service requires exclusion of allochthonous black (BC) and particulate inorganic carbon corrected for water– atmospheric equilibrium (PICeq). For the first time, we address this bias for a temperate salt marsh and a coastal tropical seagrass in BC hotspots. Seagrass TOC stocks were similar to the salt marshes with soil depths < 1 m (59.3 ± 11.3 and 74.9 ± 18.9 MgC ha-1, CI 95% respectively) and sequestration rates of 1.134 MgC ha-1 yr-1. Both ecosystems showed larger BC constraints than their pristine counterparts. However, the seagrass meadows’ mitigation services were largely constrained by both higher BC/TOC and PICeq/TOC fractions (38.0% ± 6.6% and 43.4% ± 5.9%, CI 95%) and salt marshes around a third (22% ± 10.2% and 6.0% ± 3.1% CI 95%). The results demonstrate a need to account for both BC and PIC within blue carbon mitigation assessments.


2021 ◽  
Author(s):  
Melissa A. Ward ◽  
Tessa M. Hill ◽  
Chelsey Souza ◽  
Tessa Filipczyk ◽  
Aurora M. Ricart ◽  
...  

Abstract. Salt marshes and seagrass meadows can sequester and store high quantities of organic carbon (OC) in their sediments relative to other marine and terrestrial habitats. Assessing carbon stocks, carbon sources, and the transfer of carbon between habitats within coastal seascapes are each integral in identifying the role of blue carbon habitats in coastal carbon cycling. Here, we quantified carbon stocks, sources, and exchanges in seagrass meadows, salt marshes, and unvegetated sediments in six bays along the Pacific coast of California. The salt marshes studied here contained approximately twice as much OC as did seagrass meadows, 23.51 ± 1.77 kg OC m−3 compared to 11.01 ± 1.18 kg OC m−3, respectively. Both seagrass and salt marsh sediment carbon stocks were higher than previous estimates from this region but lower than global and U.S.-wide averages, respectively. Seagrass-derived carbon was deposited annually into adjacent marshes during fall seagrass senescence. However, isotope mixing models estimate that negligible amounts of this seagrass material were ultimately buried in underlying sediment. Rather, the vast majority of OC in sediment across sites was likely derived from planktonic/benthic diatoms and C3 salt marsh plants.


2009 ◽  
Vol 134 (3-4) ◽  
pp. 269-276 ◽  
Author(s):  
Yuguang Bai ◽  
Tyler Colberg ◽  
J.T. Romo ◽  
Brian McConkey ◽  
Dan Pennock ◽  
...  

2021 ◽  
Author(s):  
Bryce Van Dam ◽  
Mary Zeller ◽  
Christian Lopes ◽  
Ashley Smyth ◽  
Michael Böttcher ◽  
...  

Abstract Long-term “blue carbon” burial in seagrass meadows is complicated by other carbon and alkalinity exchanges that shape net carbon sequestration. We measured a suite of such processes, including denitrification, sulfur, and inorganic carbon cycling, and assessed their impact on air-water carbon dioxide exchange in a typical seagrass meadow underlain by carbonate sediments. Contrary to the prevailing concept of seagrass meadows acting as carbon sinks, eddy covariance measurements reveal this ecosystem as a consistent source of carbon dioxide to the atmosphere, at an average rate of 610 ± 990 µmol m-2 hr-1 during our study and 700 ± 660 µmol m-2 hr-1 over an annual cycle. A robust mass-balance shows that net alkalinity consumption by ecosystem calcification explains >95% of the observed carbon dioxide emissions, far exceeding alkalinity generated by net reduced sulfur, iron and organic carbon burial. Isotope geochemistry of porewaters suggests substantial dissolution and re-crystallization of more stable carbonates mediated by sulfide oxidation-induced acidification, enhancing long-term carbonate burial and ultimate carbon dioxide production. We show that the “blue carbon” sequestration potential of calcifying seagrass meadows has been over-estimated, and that in-situ organic carbon burial only offsets a small fraction (<5%) of calcification-induced CO2 emissions. Ocean-based climate change mitigation activities in such calcifying regions should be approached with caution and an understanding that net carbon sequestration may not be possible.


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