November 2nd, 2013
in Op Ed
by Valerie Giesen, INESAD
Reports by the International Panel on Climate Change (IPCC) and the World Bank show that communities across South America are already feeling the impact of climate change today-and that these are likely to intensify in the future. According to the IPCC, the economies of most Latin American countries depend on agriculture, which means that climatic change and extreme weather events that affect farming also pose a tangible threat to economic prosperity and developmental goals in the region.
A 2012 World Bank Report even predicts that South America will be one of the regions hit hardest if temperatures rose by more than the internationally recognised 2°C target. This post will highlight five of the central ways in which South Americans are experiencing the effects of climate change:
1. Temperature: In South America, climate change has led to a variety of temperature changes. While the widely-cited 2007 IPCC report observed an overall 1°C increase in temperature across South America over the past decade, there has been significant regional variation, leading to diverse effects. For instance, Bolivia's highlands have actually cooled by 1°C over the past five decades, while there is some evidence for rising temperatures in the lowlands. In a 2009 World Bank Report, Drs. Lykke Andersen and Dorte Verner show that the contradictory trends of average temperatures have led to uneven social and economic effects of climate change in Bolivia. They estimate that the cooling experienced in the country's highlands has reduced income in these areas by about 2-3 percent. In the country's wealthier lowlands, no such negative trends were observed. This means that in Bolivia changes in temperature affect the population of the comparatively poor highlands disproportionately, compared to the wealthier lowland of the country.
2. Glaciers: Changing average temperatures are not the only relevant factor for understanding the impact of climate change in South America. According to the IPCC's 2008 technical paper, there has been an overall trend of glacier retreat in the highlands of Bolivia, Peru, Columbia, and Ecuador over the past decades. For instance, Colombian glaciers were reduced by 80 percent from 1990 to 2000.
Climate change means lower cloud cover in the daytime. This leads to higher temperatures in the daytime, which melt glaciers despite lower average temperatures at night.
Glaciers are important safeguards against drought as they store large amounts of water as ice. The loss of glaciers such as the Chacaltaya Glacier near La Paz-which disappeared completely in 2009-have consequences for communities' access to water. The effects are particularly severe for those parts of the population that already lack access to sufficient clean water. For instance, Chacaltaya had been an important source of water for the growing Bolivian cities of La Paz and El Alto and its disappearance has put considerable stress on water supplies, which, according to the Harvard Review of Latin America, are already short among the poorest communities. The IPCC predicts that, over the next decades, Andean glaciers are likely to disappear, which will affect water availability across the region.
3. Extreme weather events already affect communities across South America as a result of climate change. As the IPCC's 2007 report shows, for instance, in 1999 and 2005 Venezuela suffered from intense rainfall. Similarly, the fertile plains which extend westward across central Argentina from the Atlantic coast-the Argentinean 'Pampas'-experienced floods from 2000 to 2002. Meanwhile, in 2005, the Amazon was affected by a severe drought that increased the risk of forest fires. According to Jose Cuesta and his colleagues in a 2013 study on agriculture in Bolivia, recurrent climate disasters affected agricultural production in the country so strongly that they can explain around five percentage points of the 17 percent food price inflation rate observed in 2003.
These extreme instances are linked to diverse regional trends. According to the said IPCC report, while there have been increases in rainfall in southern Brazil, Paraguay, Uruguay, the Argentinean Pampas, and parts of Bolivia, there has been a decline in rainfall in Southern Chile, south-west Argentina, and southern Peru. This means that the consequences of climate change vary, often paradoxically, across the continent; some countries are simultaneously faced with a lack of water and problems associated with excessive rainfall. From 2001 to 2007, Bolivia, for example, experienced six floods and two droughts: floods damaged maize, rice, soy, and other crops, as well as large stretches of pastureland. From 2007 to 2008, regular flooding, landslides, and hail affected 618,000 people, the equivalent of 6 percent of the country's population. Droughts, accompanied by forest fires and extreme winds, destroyed corn and other rain fed crops. Similarly, Ecuador experienced three major floods from 2002 to 2008, which affected more than 400,000 people and caused an estimated US$63 million of damage.
4. Land: According to the United States Agency for International Development (USAID), South America is home to the largest continuous area of tropical forest in the world, with the Amazon basin containing some of the forests and ecosystems that are most vital for global climate. Tropical forests help regulate local and global weather. According to Rhett Butler, the founder of the conservation news site Mogabay, they absorb more heat than bare soil does and when this warmth carries moisture from forest trees into the atmosphere, it condenses as rain. In this way, tropical forests can cool local climate and help generate rainfall.
The Amazon alone creates about 50 to 80 percent of its own rainfall through transpiration. However, as a 2005 study by the U.S. National Aeronautics and Space Administration (NASA) shows, tropical forests also affect weather globally. The research found that deforestation in the Amazon region influences rainfall from Mexico to Texas and in the Gulf of Mexico. This makes degradation processes such as deforestation, wind erosion, and changes in the soil's composition all the more worrying. The IPCC claims that these already affect almost three-quarters of South America's drylands. The negative impact on biodiversity is now noticeable: in 2007, 7 out of the 25 most critical places with high concentrations of endemic species were in Latin America. This means that these species are unique to one geographic location-and their habitats are shrinking. This is due, among other factors, to increasing rates of tropical deforestation. In 2005, USAID estimated that 15 percent of the Amazon basin had already been deforested. In 2013, Greenpeace reported that according to the Brazilian government, deforestation rates increased by an estimated 26 percent in the period from August 2012 to February 2013, which means that an area of forest larger than the size of the city of London disappeared.
It is of note that these phenomena cannot be explained by climate change alone; they are also linked to the human uses of land as well as the increased use of natural resources in many countries. For instance, the IPCC reports that increasing levels of deforestation fires in the southern Amazon are connected to regional rises in temperature. Similarly, logging activities have exacerbated land degradation and substantially increased the risk of forest fires.
5. Coastal regions are already impacted by global warming, which is predicted to intensify significantly in the next decades. For instance, according to the Union of Concerned Scientists (UCS), the waters around the Northern Brazil Shelf support a $700 million fishing industry, which is critical to the regional economy and local food supply. A shelf is the extended periphery of a continent, which is typically covered by relatively shallow seas. Because sunlight permeates the shallow waters of shelves, they are usually rich in marine life. The UCS reports that rises in water temperatures by 0.9° C since 1976 have reduced the populations of microorganisms that make up the bottom of the marine food chain by up to 30 percent. According to them, this has added to the stresses on local fish stocks, which have been declining due to overfishing and destruction of mangrove habitats.
In San Andrés, a group of islands off the Columbian coast, rising water temperatures have also caused damage. Rising sea temperatures have already caused the bleaching of the islands' barrier reef; bleaching is the death of corals as a result of losing the symbiotic algae on which they rely for nutrients. Bleaching is becoming a widespread problem. Over a seven year period of monitoring, a team from the Colombian Instituto de Investigaciones Marinas y Costeras (INVEMAR) recently found a total of 34 coral species with signs of bleaching in Colombian coral reefs. This poses a threat to the local economy of the San Andrés islands: according to the governor of San Andres, 95 percent of local income is derived from tourism related activities such as diving and snorkeling, with fishing making up an additional four percent of San Andres' economy.