In contrast to the relatively robust capabilities of resource-rich first world countries in North America, the flimsy nature of third-world economics across much of South America and the Caribbean makes efforts to compensate for major disruptions to the climatic norms, such as those associated with the ongoing, historically strong El Nino, ineffective or impossible, putting millions of residents directly at the mercy of devastating droughts and torrential flooding.
Long-term drought has crippled agricultural interests across much of central and northern South America. The Alta Guajira region of northeast Colombia that depends on a substantial seasonal rainfall has been completely dry for three years. Reservoirs have evaporated, threatening the livelihoods and lives of indigenous farmers and ranchers. Coffee growers in the shadows of the Colombian Andes fear a lost harvest due to the water shortage there. Extra hours of sunlight so near the Equator ordinarily concentrate sugars in the grains, contributing to the reputation of the famous Colombian coffee bean, but the lack of rainfall threatens the crucial final stages of growth. The rainy season in these areas is customarily expected from October through mid-December, however the strengthening El Nino has caused significant deficits already (see figure at left) and is expected to slash rainfall totals by more than 60% through the next few months. The dry season that follows early next year will offer little relief for people facing already critical water shortages.
The degradation of the Amazon rainforest due to the interrelated combination of deforestation and persistent dryness has surprisingly wide-ranging impacts. The large-scale destruction of rainforest enhances the rate of carbon release back to the atmosphere, intensifying the global warming process, which in turn leads to higher temperatures, more frequent and stronger El Nino events, and resultant wildfires and deforestation, a vicious cycle threatening the Amazon basin with ever more frequent and devastating droughts. Deforestation also removes a vital contribution of moisture released by a healthy rain forest into the atmospheric “rivers” of water vapor that feed rainfall patterns all the way from southern Brazil up through the islands of the Caribbean. The resultant drought in southeastern Brazil is the worst in 80 years, especially in the Southern Hemisphere’s largest city, Sao Paulo. Reservoirs there are running as low as 12% capacity, leading to daily water cutoff periods for many residents, and what water does flow often comes out a milky white color thanks to the concentration of pollutants in low-pool reservoirs. Many factors, including poor management, decaying infrastructure, and global climate change contribute to this dangerous state of affairs, but the deficit of moisture transport from the Amazonian rain forest due to successive dry seasons makes the issue acute and deadly.
Meanwhile, portions of Argentina and Chile are likely to see continued above normal precipitation and flooding due to the El Nino. The Atacama desert in northern Chile, ordinarily one of the driest places on Earth with less than 15 mm (0.6 inches) of rain falling on average per year, has seen episodes of mudslides as well as an unusual and dazzling explosion of flower growth carpeting the desert floor. Mining and agricultural operations have been disrupted, especially the upcoming wheat harvest, not to mention the damage done by flash flooding and river surges. However, it is the prospects of long-term drought and the associated threats posed to agricultural interests and massive population centers that to many scientists and policy-makers comprise a much more ominous glimpse of things to come.