## 6 Discussion
### Merging Natural Soil CO\({}_{2}\) Flux and GPPs' CO\({}_{2}\) Emissions
Amiata volcano shallow magmatic systems and to the deeper mantle-generated and -released CO\({}_{2}\). The large volumes of the relatively shallow (4-5 km depth) magmatic system extending in subsoil over the whole AVGA allow for the homogeneous release of CO\({}_{2}\) in particular in correspondence with the vertical projection of the shallower portions of the magmatic system. The homogeneous emission of gas allows us to compare the gas flux between the areas where natural emissions are undisturbed and the areas where the production of electricity is active. The consequence of the collection, processing, and analysis of the presented data is that if the homogeneous deep gas flow is established over large areas, then the undisturbed areas can be taken as a reference to the medium-deep natural flow by verifying the effects of electricity production activities on the natural flux of gas in geothermal fields. \begin{table}
\begin{tabular}{c c c c c c} \hline  & \begin{tabular}{c} **Diffuse CO\({}_{2}\) Degassing** \\ **(Biological Component)** \\ **(\(\prime\)d)** \\ \end{tabular} & \begin{tabular}{c} **Diffuse CO\({}_{2}\) Degassing** \\ **(\(\prime\)Deep Component)** \\ **(\(\prime\)d)** \\ \end{tabular} & \begin{tabular}{c} **GPPs** \\ **(\(\prime\)d)** \\ \end{tabular} & \begin{tabular}{c} **CO\({}_{2}\) Focused** \\ **Emissions** \\ **(\(\prime\)d)** \\ \end{tabular} & \begin{tabular}{c} **Sum** \\ **(\(\prime\)d)** \\ \end{tabular} \\ \hline \begin{tabular}{c} Piancastagnaio (24.8 km\({}^{2}\)) \\ (brownfield) \\ \end{tabular} & 463 & 1466 & 770 & - & 2699 \\ \begin{tabular}{c} Bagnore (14.5 km\({}^{2}\)) \\ (brownfield) \\ \end{tabular} & 270 & 635 & 648 & 2 & 1555 \\ \begin{tabular}{c} Bagni San Filippo (12.3 km\({}^{2}\)) \\ (greenfield) \\ \end{tabular} & 229 & 1186 & - & 144 & 1559 \\ \
\begin{tabular}{c} Paglia Valley (7.13 km\({}^{2}\)) \\ (greenfield) \\ \end{tabular} & 133 & 599 & - & - & 732 \\
\begin{tabular}{c} Survey Area (280 km\({}^{2}\)) \\ \end{tabular} & 5216 & 11,038 & 1418 & 262 (\({}^{*}\)) & 17,934 \\ \hline \end{tabular}
\end{table} 
Table 7: CO\({}_{2}\) soil fluxes in different areas (brown and greenfields). GPPs data from [13]. (*) Sum of all CO\({}_{2}\) focused emissions in the Mt. Amiata volcanic–geothermal area (AVGA) area. Figure 8: Total CO\({}_{2}\) emissions in AVGA, split in its components. Figure 10: Comparison of the areal normalized CO\({}_{2}\) emissions from different sources (biological, deep, geothermal power plants (GPPs)) in the high emission areas of AVGA, greenfields, and brownfields. The contribution of CO\({}_{2}\) focused emissions have been neglected because of their very slow relative contribution. Figure 9: CO\({}_{2}\) emissions in the four high emission areas and in the AVGA area. In the Bagnore and Bagni San Filippo areas, only CO\({}_{2}\)-focused emissions located inside the two identified areas are considered. Figure 10 also shows another key point for this study's objectives. The natural emissions measured from soils are considerably lower in areas of the geothermal fields (Figure 10 and Table 8). For the Bagnore area, the contribution of deep CO\({}_{2}\) to the diffuse soil flux to the atmosphere is the same as that of emissions from power plants. For the Piancastagnaio area, the contribution to diffuse emissions of deep CO\({}_{2}\) is double that of CO\({}_{2}\) emissions from power plants. However, summing up the total emissions from soils plus the emissions from the GPPs, we observe that the emissions in geothermal areas are the same as those occurring in greenfield areas. We can observe that the Bagnore and Piancastagnaio soil emissions are significantly smaller if compared to Bagni San Filippo and Paglia areas, but they become equivalent if the contribution of GPPs emission is included in the flux. This finding shows that the depletion of emissions in the developed geothermal area is nearly balanced by the contribution of GPPs.