Estimating Global ‘‘Blue Carbon’’ Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems

Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems—marshes, mangroves, and seagrasses—that may be lost with habitat destruction (‘conversion’). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this ‘blue carbon’ can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15–1.02 Pg (billion tons) of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3–19% of those from deforestation globally, and result in economic damages of $US 6–42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats

Toxicology of Decabromodiphenyl Ether in Avian Embryos: Disposition of the Flame Retardant BDE-209 in Yolk-injected Chicken Embryos (Gallus gallus)

Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals of toxicological concern present in humans, wildlife, and the environment. Deca-BDE is the highest production product due to historical use patterns and recent regulatory limitations on the other two commercial formulations (Penta-BDE and Octa-BDE) in the U.S and Europe. The EU banned Deca-BDE starting July 1, 2008. However, it remains in usage in North America and elsewhere in the world. BDE-209 is the dominant congener in all Deca- BDE commercial products. BDE-209 has been reported to under go metabolic debromination to lesser brominated and more toxic and bioaccumulative congeners. However, insufficient data are available on this process. It has also been observed that congener profiles and BDE-209 levels in terrestrial organisms differ from most aquatic species, indicating accumulation or metabolic dissimilarity. The goal of this in ovo study is to determine the biotransformation and tissue distribution of BDE-209 after injection into the yolk-sac of embryonic chickens. An emulsion formulation was employed to better distribute the hydrophobic BDE-209 within the eggs in an attempt to better mimic “natural” exposure of embryos. Acute mortality from BDE-209 yolk injection was observed. An LD50 value of 44 μg/egg (740 ng/g ww) was determined for embryonic chickens in this study. Concentrations of BDE-209 and possible metabolic degradates were determined in five compartments of the embryos (yolk, brain, liver, heart and remaining carcass). The results indicated that some BDE-209 was mobilized from the yolk, into the carcass, liver, brain, and heart tissues of the developing chicken embryo prior to pipping. However, 80% of the dose was detected as BDE-209 in the yolk sac. Additional BDE-209 would likely have been assimilated following hatching and resorption of the remaining yolk. Nona-BDEs were detected in all of the liver and yolk samples from BDE-209 exposed eggs. The congener profiles of the different tissues did not indicate that significant metabolic debromination of BDE-209 occurred within the developing embryos

Benefit transfer with limited data: An application to recreational fishing losses from surface mining

AbstractThe challenges of applying benefit transfer models to policy sites are often underestimated. Analysts commonly need to estimate site-specific effects for areas that lack data on the number of people who use the resource, intensity of use, and other relevant variables. Here, we address issues of applying transfer functions to sites that have sparse or missing data. We present options for estimating data to apply meta-regression models (MRMs) in ways that are scale-appropriate and sensitive to local conditions. Using a case study of the potential lost welfare to freshwater anglers as a result of mountain top coal mining within West Virginia, we integrate: 1) an empirical ecological model of fish community changes; 2) an MRM that relates changes in catch rates to changes in anglers' utility; and 3) a spatial participation analysis that maps trip distribution using multiple survey datasets. We evaluate two scenarios: partial (20%) and full use of existing mine permits. Our conservative estimates of annual welfare loss are $120,500 for the partial scenario and$627,800 for the full scenario, due to changes in recreational fishing catches. These results are sensitive to catch rate assumptions and socio-demographic characteristics that varied widely depending on the spatial scale of measurement

Estimating global "blue carbon" emissions from conversion and degradation of vegetated coastal ecosystems.

Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems--marshes, mangroves, and seagrasses--that may be lost with habitat destruction ('conversion'). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this 'blue carbon' can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15-1.02 Pg (billion tons) of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3-19% of those from deforestation globally, and result in economic damages of $US 6-42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats

Estimates of carbon released by land-use change in coastal ecosystems globally and associated economic impact.

<p>Notes: 1 Pg = 1 billion metric tons. To obtain values per km², multiply by 100. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043542#s2" target="_blank">Methods</a> section for detailed description of inputs and their sources. In brief, data for global extent and conversion rate are recently published ranges (minimum - maximum, and central estimate in parentheses). For near-surface carbon susceptible to land-use conversion (expressed in potential CO₂ emissions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043542#pone.0043542-Intergovernmental2" target="_blank">[48]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043542#pone.0043542-Pearson2" target="_blank">[50]</a>), uncertainty range is based on assumption of 25–100% loss C upon land-use impact; thus, the high-end estimate is the literature-derived global mean carbon storage in vegetation and the top meter of sediment only (central estimate is thus 63% loss). Results for carbon loss are non-parametric 90% confidence intervals (median in parentheses) from Monte Carlo uncertainty propagation of the three input variables (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043542#s2" target="_blank">Methods</a>). Economic estimates apply a multiplier of US$ 41 per ton of CO₂ to lower, upper, and central emission estimates (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043542#s2" target="_blank">Methods</a>).</p

Global distribution of seagrasses, tidal marshes, and mangroves.

<p>Data sources: Seagrass and saltmarsh coverage data are from the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC); mangrove coverage data are from UNEP-WCMC in collaboration with the International Society for Mangrove Ecosystems (ISME).</p