Climate change hits Latin America , Caribbean region hard
• UN Report
April 11, 2007
The Intergovernmental Panel on Climate Change (IPCC) has concluded that, in Latin America and the Caribbean (LAC) region, there are several evidences of increases in extreme climatic events and climate change, and that the frequency of weather and climate extremes is most likely to increase.
In Belize and Guyana, the implementation of land-use planning and zoning imposed strengthened norms for infrastructure, a coastal zone management plan, the adjustment of building codes, and better disaster mitigation strategies (including floodplain and other hazard mapping) to couple with climate change considerations into the day-to-day management of all sectors.
Significant impacts of projected climate change and sea level rise are expected for 2050-2080 on the LAC coastal areas.
With most of their population, economic activities and infrastructure located at or near sea-level, they will very likely suffer flooding and erosion with high impacts on people, resources, and economic activities.
As for coastal tourism, the most impacted countries will be those where the sector contribution to the GDP balance of payment and employment is relatively high, and are threatened by windstorms and projected sea level rise, such as those of Central America, the Caribbean coast of South America and Uruguay . Thus, climate change is very likely to be a major challenge for all coastal nations.
Increase in temperature of approximately 1 degree Celsius in Mesoamerica and South America, and of 0.5 degrees in Brazil was recorded.
Over the past three decades, Latin America was subjected to climate-related impacts of increased El Niño occurrences. Two extremely intense episodes of El Niño phenomenon (1982-83 and 1997-98) and other increased climate extremes occurred during this period, contributing greatly to the vulnerability of human systems to natural disasters such as floods, droughts, landslides.
The occurrence of climate-related disasters increased by 2.4 times between the periods 1970-1999 and 2000-2005, continuing the trend observed during the 1990s. Only 19% of the events have been economically quantified between 2000 and 2005, representing losses of nearly US$20 billion.
In addition to weather and climate, the main drivers of the increased vulnerability are demographic pressure, unregulated urban growth, poverty and rural migration, low investment in infrastructure and services, and problems in inter-sector coordination.
Landslides are generated by intense/persistent precipitation events and rainstorms. Tropical forests of Latin America, particularly those of the Amazonia , are increasingly susceptible to fire occurrences due to increased El Niño-related droughts and to land-use change.
Mangrove forests located in low-lying coastal areas are particularly vulnerable to sea level rise, increased mean temperatures, and hurricane frequency and intensity, especially those of Mexico , Central America and Caribbean continental regions.
Increased rainfall in southeast Brazil , Paraguay , Uruguay , the Argentinean Pampas and some parts of Bolivia has impacts on land use, crop yields and has increased flood frequency and intensity.
In relation to land, the IPCC report said, “almost three-quarters of the dry-land surface are moderately or severely affected by degradation processes. The combined effects of human action and climate change have brought a continuous decline of natural land cover, which continues to decline at very high rates.
The expansion of the agricultural frontier and livestock, selective logging, financing of big scale projects like construction of dams for energy generation, illegal crops, construction of roads and increased links to commercial markets have been the main causes of deforestation.
By the 2050s, 50 percent of agricultural lands are very likely to be subjected to desertification and salinization, affecting 17 to 50 percent of agricultural lands in the LAC zone.
The demand of water for irrigation is projected to rise in a warmer climate, bringing increased competition between agriculture and drinking as well as industrial users, making the practice of agriculture more expensive.
Under severe dry conditions, inappropriate agricultural practices (deforestation, soil erosion, chemical abusive use) will deteriorate surface and groundwater quantity and quality.
Generalized reductions of rice yields by the 2020's, as well as increases in soybean yields, are possible.
On the other hand, cattle and dairy productivity is expected to decline in response to increasing temperatures.
Recent studies indicate that most of the South American glaciers from Colombia to Chile and Argentina are drastically reducing their volume at an accelerated rate.
Changes in temperature and humidity are the primary cause for the observed glacier retreat during the 2nd half of the 20th Century in the tropical Andes .
In the next 15 years, inter-tropical glaciers are very likely to disappear, affecting water availability and hydropower generation. By the 2020s, the net increase in the number of people experiencing water stress due to climate change is likely to be between 7 and 77 million. For the second half of the century, these numbers could reach between 60 and 150 million.
The expected increase in Sea Level Rise (SLR) and weather and climatic variability and extremes are very likely to affect coastal areas. During the last 10-20 years, the rate of SLR increased from 1 to 2-3 millimeters/year in south-eastern South America .
Low-lying coasts in several LAC countries (parts of Argentina, Belize, Colombia, Costa Rica, Ecuador, Guyana, Mexico, Panama, El Salvador, Uruguay, Venezuela) and large cities (Buenos Aires, Rio de Janeiro, Recife, etc.) are among the most vulnerable to climate variability and extreme hydro-meteorological events, such as rain and windstorms and subtropical and tropical cyclones and their associated storm surges.
SLR within the range 10-20 centimeter/century is not a main problem yet, but evidences of acceleration of SLR rates up to 2 to3 millimeter/year over the past decade suggest an increase in the vulnerability of low-lying coasts, already subjected to increasing storm surges.
Under future climate change, there is a risk of significant species extinctions in many areas of tropical LAC.
Since 1980, about 20% of the world's mangrove forests have disappeared, affecting fishing.