Description:
Projections for changes in precipitation patterns are extremely complex, involving a high degree of uncertainty and large heterogeneity. Summer climate projections under climate change scenario A1B (this scenario assumes future rapid demographic and economic growth, introduction of new and more efficient technologies, accompanied by a balanced use of all types of energy sources) show a reduction in precipitation of between 5% and 10% by the end of the century (2090-2099) in Central America as compared to 1980-1999. For much of Mexico, southern Chile and the northeastern portion of the Bolivarian Republic of Venezuela, the decrease is projected to be between 10% and 20%. Projections call for a summer-time increase in the rainfall regime of between 5% and 10% in Ecuador, central and southern Colombia, eastern Argentina and much of Peru. For the winter season, the greatest changes in precipitation are expected to occur in Central America, southern Mexico, the northern portion of the Bolivarian Republic of Venezuela and the eastern portion of Brazil, with reductions of between 10% and 20%. These changes in precipitation are important primarily because of their impact on water availability, re-supply of aquifers, maintenance of plant cover and agricultural yields in the region.