Geoscience Reference
In-Depth Information
As sea level rises, the potential for dis-
placement of people is larger on deltas
than any other place on Earth. Deltas are
low in elevation and, as a consequence, are
susceptible to storms, tsunamis, and par-
ticularly to sea level rise. Cyclone Nargis,
which killed at least 150,000 people on the
Irawaddy Delta in Myanmar in 2008, is
only the latest delta catastrophe. The rising
sea will also be particularly hard on agri-
culture in deltas. A study by X. Chen of the
impacts on the Yangtze Delta predicts that
rising seas will prolong the waterlogging
of fields as groundwater levels are raised.
During dry periods saltwater intrusion will
occur on an ever-larger scale above ground-
water levels.
Fifteen million people live at elevations
within a meter of sea level on the Ganges-
Brahmaputra Delta (the world's largest
delta), most of whom will become refugees
within the next fifty years. In wealthier so-
cieties it is likely that billions of dollars will
be spent to fight the rising sea on deltas.
Holland, which occupies the Rhine-Meuse
Delta, will most likely succeed through ex-
tensive, massive, and costly engineering ef-
forts. Globally, all delta communities (with
the possible exception of Holland) will be
abandoned within this century. New Or-
leans is a goner.
The three global delta hot spots as mea-
sured by the number of people that will be
forced to leave their homes by a one-meter
(three-foot) sea level rise are the Mekong,
Ganges, and Nile deltas. Rick Tutwiler of
the American University in Cairo describes
the Nile Delta as a “kind of Bangladesh
story”—on top of all the population, water,
and pollution problems “there is the rising
sea—a perfect storm.” Based on a World
Bank study of eighty-four coastal areas,
the rise in Vietnam will displace a third of
the population in the Mekong Delta, where
half the country's rice is grown. A full third
of Ho Chi Minh City would be inundated
by a one-meter (three-foot) sea level rise.
Vietnam's Red River Delta in the north will
also suffer population displacement and
loss of rice production.
Unfortunately in Vietnam the situation
just got more complicated. A major dam
has just been constructed on the Mekong
River in China. As has happened on the
Mississippi, the Nile, and the Niger River
Deltas, the loss of sediment, which will be
trapped behind the dam, will cause shore-
line erosion and delta sinking. Adding sea
level rise into the mix only intensifies these
problems.
Myths, Misinterpretations, and
Misunderstandings of the Deniers
myth
: Coastal engineering will save the day
and hold shorelines in place and prevent in-
undation!
In a coastal management news-
letter in Florida in 2010, readers were as-
sured that engineers could solve the sea
level rise problem. Bjørn Lomborg in some
of his writing implies that the sea level rise
problem is solvable, presumably by engi-
neering. Although engineering could “save
