When compared to the total annual greenhouse gas emissions
in CO2 equivalents as reported by the UNFCCC Greenhouse Gas Inventory Data for the last inventory year excluding land-use changes (http://unfccc.int/ghg_data/items/3800.php), one observes that the Mediterranean Sea is overall responsible for sequestrating 0.7% of the total yearly emissions of the neighboring countries. On a country-by-country basis, such value is highest for Malta (10.1%), Tunisia (3.9%), and Algeria (3.4%). Marine biological processes are responsible for the sequestration of 10.5% and 5.8% of the total emissions of Malta and Cyprus, respectively.
The spatial distribution of the estimated yearly flows of economic value of CO2 sequestration and the aggregated average values over Mediterranean EEZs – under current conditions and based on the partial equilibrium approach described in the previous section – are presented in Fig. 5 and Table 2, respectively. The values were calculated using the EC (DECC, 2009) estimate of the SCC. Fig. 5 illustrates the yearly average value flows at a 1/8- degree resolution, i.e., for a grid cell size ranging between 69 and
156 km2, over the period 2001–2005.
In monetary terms, the estimated current value of carbon sequestration over the entire Mediterranean basin amounts to
337.3 million s/year, out of which 281.4 million s/year can be
attributed to the biological pump. At the level of individual EEZ, the highest aggregated values for all considered biogeochemical processes and for the biological processes only are found
respectively in Spain (105.1 million s/year) and Greece (58.8 mil-
lion s/year). On average, one square kilometer of Mediterranean
Sea provides carbon sequestration services in the value of 133.5 s/
km2. The value flow for biological processes when estimated separately amounts to 111.4 s/km2. The highest values per unit of area are found in Morocco (1013.3 s/km2) and Slovenia (186.2 s/ km2) for, respectively, all biogeochemical processes and biological
processes only. Notably, several EEZs in the Levantine Sea present a negative value flow. This should be regarded as the costs related to net carbon emissions in the atmosphere from those zones. Also in these cases, biological activity provides a positive contribution, which mitigate the cost.