這份報告由中美洲開發銀行（Inter-American Development Bank）、拉丁美洲暨加勒比海經濟委員會（ Economic Commission of Latin America）、世界自然基金會（WWF）聯合撰寫。報告的初步結果5日已於華盛頓發表。
Latin America and the Caribbean face damages of $100 billion every year by 2050 if the global temperature rises just two degrees Celsius over pre-industrial levels, finds a new report to be released at the United Nations Rio+20 summit on sustainable development later this month.
The two degree Celsius rise is often cited by scientists as the level at which world leaders must stabilize the climate to avert the worst consequences of climate change. But a rise of two degrees C over pre-industrial levels is now seen as "unavoidable with significant negative effects in economic activities, social conditions and on ecosystems," according to the report.
Jointly produced by the Inter-American Development Bank, the Economic Commission of Latin America and the Caribbean and the World Wildlife Fund, the report's preliminary findings were presented Tuesday in Washington.
Countries in Latin America and the Caribbean are "especially vulnerable" to climate warming, although they contribute only 11 percent of the world's greenhouse gas emissions. This figure has declined 11 percent since the start of the century, a period of overall growth in regional GDP, due to reductions in land use emissions and improvements in energy efficiency.
The region's vulnerability stems from dependence on natural resources, an infrastructure network that is susceptible to climate events, and the presence of bio-climate hotspots such as the Amazon basin, the Caribbean coral biome, coastal wetlands and fragile mountain ecosystems.
Regional damages will result from diminishing agricultural yields, disappearing glaciers, flooding, droughts and changing rainfall patterns, among other events triggered by a warming planet, explains the report, "The Climate and Development Challenge for Latin America and the Caribbean: Options for Climate Resilient Low Carbon Development."
Key impacts in the region by about 2050 are projected to include partial collapse of the coral biome in the Caribbean, disappearance of most glaciers under 5,000 meters (16,400 feet) in the Andes, the likelihood of some degree of savannization 草原化 in the Amazon Basin, reduction in agricultural yields of many staple crops, increased flooding and inundation of coastal zones, increased exposure to tropical diseases, destabilization of the hydrological cycle in major basins, and the intensification of extreme weather events.
Mexico and Brazil have the largest land distribution just above sea level, making those countries vulnerable to rising sea levels. A rise of one meter (39 inches) in the sea level could affect 6,700 kilometers (4,160 miles) of roads and cause extensive flooding and coastal damage, the report projects.
"Many climate-related changes are irreversible and will continue to impact the region over the long term," said lead researcher Walter Vergara, the Inter-American Development Bank's division chief of climate change and sustainability.
"To prevent further damages, adaptation is necessary but not enough. Bolder actions are needed to bend the emissions curve in the coming decades," said Vergara.
On the positive side, the report calculates the cost of investments in adaptation to address these impacts is much smaller, about one-tenth the physical damages.
Steep cuts in global emissions of greenhouse gases are needed to avert some of the potentially catastrophic longer term consequences of climate change, the report advises.
The report identifies ways to bend the emission curve to two tons per capita, by promoting zero net emissions from deforestation and other land-use practices by 2030, combined with efforts to eliminate the carbon footprint in the power and transport sectors by 2050, at an annual cost of $110 billion.
"In the long term," said Vergara, "this is the surest way to ensure Latin America and the Caribbean continues to prosper along a sustainable path.