# Impacts of Climate Change on Blue Carbon Stocks and Fluxes in Mangrove Forests
## 4 Predictions  
The impacts of climate change on blue carbon stocks and cycling in mangrove forests are not readily clear cut. While increasing temperatures and CO\({}_{2}\) concentrations lead separately to increased carbon production in one-factor experiments, factorial studies indicate complex responses depending on interactive effects between salinity, temperature, and CO\({}_{2}\) levels as well as species-specificity. Despite these caveats, increased anthropogenic CO\({}_{2}\) emissions can in principle affect the health of mangrove forests (Table 4).  
Other factors that will determine whether mangrove carbon stocks and cycling will respond positively, negatively, or not at all, include local geomorphology and weather, species composition, soil type and origin, nutrient availability, and forest age. It is clear  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Climate Change** & **Blue Carbon Stocks** & **Carbon Fluxes** \\ \hline \multirow{8}{*}{SLR} & Outcome dependent on scenario and species (flood tolerance): & Outcome dependent on scenario and species (flood tolerance): \\  & (1) critical SLR threshold \(\approx\) 6 mm a\({}^{-1}\). Survival only under very low-low CO\({}_{2}\) emissions scenarios. & (1) critical SLR threshold \(\approx\) 6 mm a\({}^{-1}\). Survival only under very low-low CO\({}_{2}\) emissions scenarios. \\  & (2) tidal migration or latitudinal expansion = + biomass and soil C & (2) tidal migration or latitudinal expansion = + \\  & (3) forest death = + soil C\({}_{r}\) – biomass C\({}_{t}\) + peat formation/C burial & CO\({}_{2}\) and CH\({}_{4}\) emissions (3) forest death = + in CO\({}_{2}\) and CH\({}_{4}\) emissions (4) under high coastal squeeze, \(-\) of 3.4 Pg C in CO\({}_{2}\) emissions (5) under low coastal squeeze, \(-\)1.1 Pg C \\ \hline \multirow{2}{*}{Increasing \({}^{\circ}\)C} & + in carbon stocks up to critical \({}^{\circ}\)C threshold \(-\) in carbon stocks in arid regions with continuing expansion & + in CO\({}_{2}\) assimilation and \(-\) respiratory losses up to critical \({}^{\circ}\)C threshold \(-\) above \({}^{\circ}\)C threshold \\ \hline \multirow{2}{*}{Increasing Storms} & \(-\) damage carbon biomass losses and soil carbon erosion & \(-\) CO\({}_{2}\) losses nutrients exhausted + or \(-\) if storm-induced massive bedload sedimentation \\ \hline Extreme Weather Events & \(-\) massive dieback & \(-\) carbon export and CO\({}_{2}\) and CH\({}_{4}\) cycling \\ \hline \multirow{2}{*}{Precipitation Changes} & + in regions of increased rainfall \(-\) in regions of decreased rainfall \(-\) in regions of decreased rainfall \\ \hline \multirow{2}{*}{Rising CO\({}_{2}\)} & Responses species-specific and complex due to interactive effects with \({}^{\circ}\)C, \%, CO\({}_{2}\) level, etc.: + most species, but \(-\) or 0 for some species & Responses species-specific and complex due to interactive effects with \({}^{\circ}\)C, \%, CO\({}_{2}\) level, etc.: + most species, but \(-\) or 0 for some species & \(-\) in regions of decreased rainfall \\ \hline Coastal Acidification & 0 & 0 \\ \hline Increasing Hypoxia & 0 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Forecasted impacts of various climate change issues on mangrove blue carbon stocks and fluxes. 0 = no impact; + = positive response; \(-\) = negative response.  
from current data and models, however, that large blue carbon losses and gains will likely occur in mangrove forests under various aspects of climate change. Further studies will no doubt discover other interacting drivers of mangrove change.  
This research received no external funding.  
Data Availability Statement: Data in this paper originate from the referenced publications.  
The author declares no conflict of interest.