13.3.2 Land-use changes
Deforestation in Latin America’s tropical areas will be one of the most serious environmental disasters faced in the region. Currently, Latin America is responsible for 4.3% of global GHG emissions. Of these, 48.3% result from deforestation and land-use changes (UNEP, 2000). By 2010 the forest areas in South and Central America will be reduced by 18 Mha and 1.2 Mha, respectively. These areas (see Figure 13.3) will be used for pasture and expanding livestock production (FAO, 2005).
Figure 13.3. Predicted 2000-2010 South American and Central American deforestation hotspots and diffuse deforestation areas (available at: http://www.virtualcentre.org/en/dec/neotropics/south_america.htm and http://www.virtualcentre.org/en/dec/neotropics/central_america.htm).
If the 2002-2003 deforestation rate (2.3 Mha/yr) in Brazilian Amazonia continues indefinitely, then 100 Mha of forest (about 25% of the original forest) will have disappeared by the year 2020 (Laurance et al., 2005), while by 2050 (for a business-as-usual scenario) 269.8 Mha will be deforested (Moutinho and Schwartzman, 2005). By means of simulation models, Soares-Filho et al. (2005) estimated for Brazilian Amazonia that in the worst-case scenario, by 2050 the projected deforestation trend will eliminate 40% of the current 540 Mha of Amazon forests, releasing approximately 32 Pg (109 tonnes/ha) of carbon to the atmosphere. Moreover, under the current trend, agricultural expansion will eliminate two-thirds of the forest cover of five major watersheds and ten eco-regions, besides the loss of more than 40% of 164 mammalian species habitats.
Projected to be one of the main drivers of future land-use change, the area planted to soybeans in South America is expected to increase from 38 Mha in 2003/04 to 59 Mha in 2019/20 (Maarten Dros, 2004). The total production of Argentina, Brazil, Bolivia and Paraguay will rise by 85% to 172 million tonnes or 57% of world production. Direct and indirect conversion of natural habitats to accommodate this expansion amounts to 21.6 Mha. Habitats with the greatest predicted area losses are the Cerrado (9.6 Mha), dry and humid Chaco (the largest dry forest in South America, which covers parts of Argentina, Paraguay, Bolivia and Brazil; 6.3 Mha), Amazon transition and rain forests (3.6 Mha), Atlantic forest (1.3 Mha), Chiquitano forest (transition between Amazonian forest and Chaco forest; 0.5 Mha) and Yungas forest (0.2 Mha). This massive deforestation will have negative impacts on the biological diversity and ecosystem composition of South America as well as having important implications for regional and local climate conditions.