13.2 Current sensitivity/vulnerability

13.2.1 What is distinctive about the Latin America region?

Latin America is highly heterogeneous in terms of climate, ecosystems, human population distribution and cultural traditions. A large portion of the region is located in the tropics, showing a climate dominated by convergence zones such as the Inter-tropical Convergence Zone (ITCZ), and the South Atlantic Convergence Zone (SACZ) (Satyamurty et al., 1998). The summer circulation in tropical and sub-tropical Latin America is dominated by the North America Monsoon System, which affects Mexico and parts of Central America, and the South America Monsoon System, which affects tropical and sub-tropical South America east of the Andes. These monsoon climates are closely interconnected with ocean-atmosphere interactions over the tropical and sub-tropical oceans. Low Level Jets in South America east (Marengo et al., 2004) and west (Poveda and Mesa, 2000) of the Andes, and in North America east of the Rockies, Baja California and over the Intra-Americas Seas transport moisture from warm oceans to participate in continental rainfall. Most of the rainfall is concentrated in the convergence zones or by topography, leading to strong spatial and temporal rainfall contrasts, such as the expected sub-tropical arid regions of northern Mexico and Patagonia, the driest desert in the world in northern Chile, and a tropical semi-arid region of north-east Brazil located next to humid Amazonia and one of the wettest areas in the world in western Colombia. A remarkable ecogeographical zone is that of the South America’s highlands (see case study in Box 13.2), located in the tropics and presenting paramo-like (neotropical Andean ecosystem, about 3,500 m above sea level) landscapes with deep valleys (yungas) holding important biodiversity, with a wealth of vegetal and animal species.