Relative changes in precipitation In percentages

December-February June-August

20 %

10 5 -5 -10 -20

Note: Relative changes in precipitation for 2090-2099, compared to 1980-1999, according to SRES emissions scenario A1B. Areas in white represent areas for which more than 66% of the models agree on the sign of change.

Source: IPCC: Climate Change 2007 Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007.

Figure 1.3

greatest changes in precipitation are expected to occur in Central America, southern Mexico, the northern portion of the Bolivarian Republic of Venezuela and the eastern portion of Brazil, with reductions of between 10% and 20%. These changes in precipitation are important primarily because of their impact on water availability, re-supply of aquifers, maintenance of plant cover and agricultural yields in the region.

With regard to changes in sea levels resulting exclusively from changes in ocean density and circulation patterns, results of atmosphere- ocean general circulation models (AOGCM) for scenario A1B show that there will be significant spatial variability, i.e., changes in sea levels will not be uniform. Thus, it is expected that by the end of the century (2090- 2099) there will be major rises in sea levels in the Caribbean and the Atlantic compared to 1980-1999 levels – attributable to the change

8

in density and ocean circulation patterns – which (except for the southeastern coast of Argentina and the eastern coast of Brazil) are expected to be as much as 5 cm greater than the projected world average of between 0.21 meters and 0.48 meters. Indeed, these same models predict that increases in Pacific sea levels will be less than the world average of 5 cm (figure 1.4). This rise in sea levels is associated, in part, with the melting of glaciers (Church and Gregory, 2001, Dyugerov, 2002, 2003 and Ringot, 2003).