Sea level rise caused by the melting of mountain and subpolar glaciers Sea level change, mm per year

0.5 1.0 1.5

0 -0.5 -1.0

Sources: Institute of Arctic and Alpine Research; Church and Gregory, 2001; Dyugerov, 2002; Ringot, 2003 1960

1965 1970 1975 1980 1985 Figure 1.4a

Changes in precipitation and temperature influence changes in runoff and in the availability of water (IPCC, 2007b). Results from models of changes in runoff are consistent with predictions for precipitation: for 2090-2099, in areas for which increases in the rainfall regimen are expected, increases in runoff are also projected. The anticipated changes in runoff, as with changes in temperature and precipitation, vary from one country to another within the region. The greatest changes projected (between 10% and 30%) will occur in eastern Argentina and southern Brazil, while the most significant decreases (between 10% and 30%) are predicted for Mexico, Central America and Chile (figure 1.5). Declines in runoff could even accelerate in dry regions, owing to the lower levels of rainfall, and as a result of higher rates of evapotranspiration brought on by the rise in temperature (IPCC, 2007b).

Change in sea level as a result of changes in ocean density and circulation (metres)

1990 1995

Cumulative contribution of glacier melt to sea level rise (20% of the observed rise by 1998)

Annual sea level fluctuations due to glacier melt

Sea level rise, mm

10 12 14

4 6 8

2 0

0.1 m

0.0 -0.1 -0.2

Note: Local sea level change due to ocean density and circulation change between

1980-1999 and 2090-2099 for the SRES A1B emissions scenario. Positive values indicate greater local than global sea level change.

Source: Meehl, G.A. et al., Global Climate Projections, IPCC, 2007. Figure 1.4b 9