1 Research Group Climate Change and Security (CLISEC), KlimaCampus, Center for Earth System Research and Sustainability (CEN), University of Hamburg, Grindelberg 5/7, 20144 Hamburg, Germany. Electronic address: balbo@cantab.net.
2 Department of Maritime Civilizations, Recanati Institute for Maritime Studies, University of Haifa, 199 Aba Koushy Ave, Mount Carmel, 3498838 Haifa, Israel.