Weather and climate stresses increase drought impacts.
Natural ecosystems, agriculture, water resources and human health in Latin America have been impacted by unusual extreme weather events reported in the past years. For example, the tropical forests of Amazonia are increasingly susceptible to fire occurrences due to increased El Niño-related droughts. Droughts related to La Niña create severe restrictions for water supply and irrigation demands in central western Argentina and central Chile between 25°S and 40°S. Droughts related to El Niño impacts on the flows of the Colombia Andean region basins (particularly in the Cauca river basin), are causing a 30% reduction in the mean flow, with a maximum of 80% loss in some tributaries, whereas the Magdalena river basin also shows high vulnerability (55% losses in mean flow). Consequently, soil moisture and vegetation activity are strongly reduced/augmented by El Niño/La Niña in Colombia.
Hydropower is the main electrical energy source for most countries in Latin America, and is vulnerable to large-scale and persistent rainfall anomalies due to El Niño and La Niña. A combination of increased energy demand and drought caused a virtual breakdown in hydroelectricity generation in most of Brazil in 2001, which contributed to a gross domestic product (GDP) reduction of 1.5%.
Droughts favoured the development of epidemics in Colombia and Guyana, and outbreaks of hantavirus pulmonary syndrome have been reported for Argentina, Bolivia, Chile, Paraguay, Panama and Brazil after prolonged droughts, probably due to the intense rainfall and flooding following the droughts, which increases food availability for peri-domestic (living both indoors and outdoors) rodents. Prolonged droughts in semi-arid north-eastern Brazil have provoked rural-urban migration of subsistence farmers, and a re-emergence of visceral leishmaniasis. A significant increase in visceral leishmaniasi in Bahia State (Brazil) after the El Niño years of 1989 and 1995 has also been reported. Human migration resulting from drought, environmental degradation and economic reasons may spread disease in unexpected ways, and new breeding sites for vectors may arise due to increasing poverty in urban areas and due to deforestation and environmental degradation in rural areas.
Land-use changes have intensified the use of natural resources and exacerbated many of the processes of land degradation.
Almost three-quarters of the drylands are moderately or severely affected by degradation processes. The combined effects of human action and climate change have brought about a continuous decline in natural land cover at very high rates. In particular, rates of deforestation of tropical forests have increased since 2002 due to land-use change (deforestation, selective logging and forest fragmentation). There is evidence that biomass-burning aerosols may change regional temperature and precipitation in the southern part of Amazonia. Biomass burning also affects regional air quality, with implications for human health. Land-use and climate changes acting synergistically will increase vegetation fire risk substantially and hence a potential increase in land degradation.
Future sustainable development plans should include adaptation strategies to enhance the integration of climate change into development policies.
Some countries have made efforts to adapt, particularly through conservation of key ecosystems, early warning systems, risk management in agriculture, strategies for flood, drought and coastal management, and disease surveillance systems. However, the effectiveness of these efforts is outweighed by, among others: a lack of basic information, observation and monitoring systems; lack of capacity building and appropriate political, institutional and technological frameworks; low income; and settlements in vulnerable areas. Without improvements in these areas, the sustainable development goals of Latin America countries will be seriously compromised, adversely affecting, among other things, their ability to reach the Millennium Development Goals (MDGs).