Fighting rising seas is hardly a new undertaking for the Dutch.
Their country has been sinking ever since Roman-era farmers began
draining their marshy lands to plant crops. Those ancient Dutchmen
soon discovered an unfortunate fact of geology: Drained land tends to
settle and sink with the falling water table. To stop their lands from
turning into swamps, the Dutch built dikes and canals around their
fields and towns and used windmills to keep them pumped dry. This
made their land sink even faster, so the Dutch built ever-larger dikes,
canals, and seawalls to keep the water at bay.
In the twentieth century, the Dutch went on the offensive, diking
and draining vast sections of the seafloor to create an entirely new
province. A 20-mile-long dam was constructed across the mouth of the
Zuider Sea, converting it into a freshwater lake, and thousands of
square miles of shallow sea bottom were ringed with dikes and slowly
pumped dry. It took years to convert the oozing mudflats into prime
agricultural land, some of which is now tended by the grandchildren of
the reclamation workers. Today a quarter million people live in the
“New Lands” and another nine million Dutch citizens live in other
parts of the country that lie below sea level.
Ironically, when it comes to global warming, the ultimate “low
country” has little to fear from the sea itself. That is because in past
decades and centuries, the Netherlands has built more than $2.5 tril-
lion worth of water defenses, explains John G. de Ronde of the National
Institute for Coastal and Marine Management in The Hague. “The fact
that we have existing infrastructure makes it relatively simple to cope
with sea-level rise,” he says.
More than a decade ago, de Ronde’s institute examined how vari-
ous sea-level rise scenarios would affect the country, factored in
expected increases in North Sea storm activity, and formulated a plan
to address the dangers before they ever came to pass. Seawalls will
have to be raised and strengthened. Major modifications will be made
to the great dam at the mouth of the Zuider Sea, which controls the
young lake’s level by releasing water into the North Sea at low tide; if
the world’s sea levels rise significantly, the dam will no longer function
properly.
It was de Ronde’s team that determined the total costs of defend-
28 Colin Woodard