The magnitude of impacts from sea-level rise
Even for today’s socio-economic conditions, both regionally The densely populated megadeltas are especially vulnerable to
and globally, large numbers of people and significant economic sea-level rise. More than 1 million people living in the Ganges-
activity are exposed to sea-level rise (Figure 6C.11). Brahmaputra, Mekong and Nile deltas will be directly affected
simply if current rates of sea-level rise continue to 2050 and
With no additional coastal protection a 40 cm rise in sea level there is no adaptation. More than 50 000 people are likely to
by the 2080s (see Figure 6C.5) would result in more than 100 be directly impacted in each of a further nine deltas, and more
million people being flooded annually, regardless of which socio- than 5000 in each of a further 12 deltas
39
. Some 75 per cent of
economic scenario is adopted (Figure 6C.12). Under this adapta- the population affected live on the Asian megadeltas and del-
tion scenario of no additional protection response, most of these tas, with a large proportion of the remainder living on deltas in
people might be forced to move to higher locations. Upgraded Africa. These impacts would increase dramatically with acceler-
coastal defences can reduce the impacts substantially: in many ated sea-level rise.
cases to levels lower than estimated for the baseline (in 1990).
170 GLOBAL OUTLOOK FOR ICE AND SNOW