Caribbean coasts of Mexico, Belize, Guatemala and Honduras, is the second longest barrier reef in the world and is one of the most diverse coral reefs in the western Atlantic. Home to over 500 fish species, 66 stony coral species and the largest population of endangered manatees in Central America, the reef is also the basis of much of the region’s economy (Kramer and Kramer, 2002).

1.5.5.2 Climate change and agriculture in Latin America
and the Caribbean

LAC is a very heterogeneous region in terms of climate, ecosystems and population distribution. Nonetheless, most productive activities are based on natural ecosystems and this land use interacts in a complex way with climate. Due to this complexity and the heterogeneity that characterizes the region, it is difficult to identify the effects of and vulnerability to climate change.

          The Intergovernmental Panel on Climate Change (IPCC, 2007), in its latest report, forecasts a change in temperature of up to 5.8°C for this century. This climate change has the potential to create local and regional conditions that include deficits and surpluses of water in the same geographic location (Table 1-7). The potentially grave impacts that can be expected, according to the IPCC, are a considerable increase in heat waves, storms, floods, landslides and avalanches unleashed by the forecast increases in the intensity of precipitation and the rising sea level. There may be health problems in human beings, livestock and crops due to the greater incidence of pests and insects that are vectors of disease.

          In addition, an increase is predicted in the sea level of up to 88 centimeters in this century, affecting (due to the intrusion of sea water in the soils subjacent to arable lands and also due to temporary and permanent flooding) approximately 30% of the agricultural regions worldwide. It is believed, in particular, that riparian and coastal settlements are at risk, but urban floods may also be a serious problem for water supply and for waste management systems that have not been designed with sufficient capacity to prevent the spread of tropical diseases. The IPCC (1997, 2001a) had already identified the following sectors as those that will be most affected by climate change in LAC: natural ecosystems

(e.g., forests, wetlands, savannahs), water resources, coastal zones, agriculture and human health.

Although LAC accounts for only 4% of global emissions of greenhouse gases, the potential impacts of climate change in the region may be considerable and very costly, in both economic and social terms. In addition, the carbon emissions that result from massive deforestation in LAC have the potential to alter the carbon balance globally.

Most productive activities in LAC depend on the availability of water, such that any climate change that results in a shortening of the rainy season, greater variability of precipitation and/or greater frequency of years without rain will have extremely negative consequences for the region (IPCC, 2001a). Mexico, in particular, will be very significantly affected by drier and hotter climatic conditions as it is already suffering from very little and highly variable precipitation (Liverman and O’Brian, 1991). The Brazilian Northeast is another region highly vulnerable to drought caused by climate change. Under different climate change scenarios, global models project reductions of up to 53% in the yields in this region (Rosenzweig et al., 1993); it will be common for there to be years in which it doesn’t rain and the population suffers hunger and is forced to migrate (Magalhães and Glantz, 1992).

Another effect of climate change on the productive activities of the region has to do with the effects of the Southern Oscillations, El Niño. Although there is no consensus on the effect of climate change on the El Niño phenomenon in the long term, in the short term an increase is reported in its frequency and intensity (IPCC, 2001a). In Central and South America, the relationship between El Niño and changes in precipitation is well-documented. El Niño is associated with massive fluctuations in the marine ecosystems of the western coast of South America (Ecuador, Peru and Chile), adversely affecting fishing and taking a devastating socioeconomic toll on the communities that depend on this activity (Pauly and Tsukayama, 1987; Sharp and McLain, 1993). In 2001, El Niño caused severe droughts in Central America and northern South America, with damages estimated at US$189 million, 66% of these in agriculture and affecting 600,000 people in Central America, mostly small-