March 21, 2012
Climate Change Imperils Coastal Cities in US
by Robert Kropp
In a new report, Climate Central finds that millions of US residents are at risk from rising sea
levels and increasing numbers of storm surges.
Since 1880, average sea levels have increased by more than eight inches, most if not all of which
can be attributed to the impacts of climate change. According to Climate Central, in a report entitled Surging Seas, unchecked climate change is
likely to make things much worse, and soon.
The study projects that sea levels could rise
as much as an additional eight inches by 2030. Furthermore, "The rate of rise is accelerating,"
Climate Central reports. "Scientists expect 20 to 80 more inches this century."
One effect of rising sea levels is likely to be massive migration by populations in
low-lying areas. The Center
for International Earth Science Information Network (CIESIN) has estimated that there could be
as many as 700 million climate refugees by 2050. And CIESIN states, "Sea-level rise appears to be
the impact most certain to result in displacement and resettlement."
"Migration may be the
only adaptive response," the Center continued. Cynthia McHale of
Ceres recently reported on an extreme example of migratory adaptation, writing, "The President
of Kiribati, a low lying nation of small South Pacific islands, announced that his country was
buying 6,000 acres of land in Fiji because climate driven sea level rise is threatening to submerge
his country. The plan of last resort is to move the entire population of 103,000 to Fiji."
In case the US-based reader is tempted to breathe a sigh of relief that the initial impacts
will be felt at such a distance, it must be noted that the Surging Seas report focuses on impacts
at home. Fifty-five sites within the US were analyzed, and the report finds that three-quarters of
them—nearly five million people in 2.6 million homes—live in areas lower than four feet above the
high tide line; but average sea levels have already exceeded four feet. An additional 3.7 million
people live less than one meter above the high tide line.
"The population and homes
exposed are just part of the story," the report states. "Flooding to four feet would reach higher
than a huge amount of dry land, covering some 3 million acres of roads, bridges, commercial
buildings, military bases, agricultural lands, toxic waste dumps, schools, hospitals, and more."
To make matters even worse, Climate Central observes, "Rising seas dramatically increase
the odds of damaging floods from storm surges." The likelihood of so-called "century floods"—floods
that are unlikely to appear more than once in a century—is expected to double by 2030. In fact, at
two-thirds of the locations analyzed by Climate Central, the annual risk of such floods has already
In New Jersey, the projected sea level rise is 15 inches by 2050, and the
likelihood of century floods will have more than tripled by 2030.
Half the exposed
population, as well as eight of the ten most vulnerable cities, are located in Florida. The state
is already experiencing flooding at extreme high tides and contamination of freshwater aquifers by
the ocean. Because southern Florida uses man-made canals to handle storm runoff, six inches in sea
level rise will cripple the system.
As McHale of Ceres notes, the Florida Climate
Institute has estimated that sea levels in the state could increase by as much as 32 inches by
Climate Central projects that about $30 billion in taxable property located in just
three counties in southeast Florida is vulnerable. The projection doesn't include Miami-Dade
County, where more homes are at risk than in any other county in the nation.
The city with
the largest population living on land less than four feet above local high tide is New Orleans.
In 2011, property and casualty insurance losses in the US totaled $44 billion; and, as
Pete Thomas, Chief Risk Officer at Willis Re, said at a Capitol Hill press conference held earlier
this month, "Demographics and coastal urbanization are catastrophic force multipliers making
weather events increasingly more costly." Representatives from the reinsurance industry called on
policymakers to enact legislation that meaningfully addresses the reality of climate change.
"A warming climate will only add to this trend of increasing losses, which is why action is
needed now," Mark Way, the Head of Sustainable Development at Swiss Re, said.
complicate worse-case scenarios even further, McHale writes, "With the Fukushima nuclear disaster
fresh in mind, it's worth noting that more than a dozen US nuclear power plants sit in low-lying
coastal areas, too."
In the absence of meaningful action by legislators, Climate Central
has documented a
number of regional action plans addressing the effects of climate change on coastal areas. Texas Sea Grant, for
example, made the following recommendations:
• Reform the National Flood Insurance
Program by ending the practice of subsidizing insurance in hazardous areas;
mandates for effective community plans that incorporate hazard mitigation planning;
adherence by vulnerable cities to state of the art building codes; and
engineered solutions such as seawalls, levees, and dikes for "truly inevitable cities in impossible
places," such as New Orleans.
"We are past the point where we can prevent climate change;
the question now is how to mitigate the risks and the dire and predictable economic and social
disruption that will inevitably follow," McHale of Ceres concluded. "The answer isn't a mystery: we
need a rapid transition to a low-carbon economy. DC policymakers need to stop fiddling while the
invisible tsunami builds just off our shores."