By Richard Wildermann for The Island Eye News
In the Feb. 17 edition of The Island Eye News, Mr. Wildermann discussed evidence of sea level rise, its causes, and efforts to slow its advance. In Part II, he explains how a few nations and communities are adapting to rising seas.
How do we adapt?
Convincing citizens and governments to invest in expensive measures to adapt to sea level rise will be difficult because it is not considered an immediate problem. Politicians react primarily to constituents’ current concerns such as traffic congestion, teacher shortages, and transgender bathrooms. It’s easier to let the next generation deal with the rising sea. But out of necessity, islands, cities, and countries around the globe are taking action.
The particular environmental characteristics of a coastal area determine the best mix of measures to adapt to rising seas. Enhancing nature’s own defenses by protecting and extending sand dunes, shoreline vegetation, and salt marshes usually provides short-term defenses against waves and storm surge. When natural barriers become overwhelmed – and in urban areas where they have been flattened, filled, and paved over – man made remedies are employed such as raising roads and buildings, constructing seawalls, and expanding flood drainage systems. Once our ingenuity reaches its limits, populations have to move to higher ground.
Many island nations are using a combination of natural defenses, engineered solutions, and migration. Most of the population of Kiribati has already moved to one island, Tarawa, where the capital city is less than 10 feet above sea level. The villagers plant mangrove seedlings to stabilize lagoons and slow erosion, and they build seawalls with sand bags as a brace against pounding waves and flood surge. The government and aid agencies help villagers plant more resilient crops.
The people of Kiribati are determined to maintain their traditions and way of life. One islander built a house powered by a solar panel to help reduce Kiribati’s infinitesimally small carbon footprint. But these are temporary measures, not a remedy for the relentless rising sea. So in 2014 the Kiribati government purchased about eight square miles of land in Fiji, about 1,200 miles to the southwest. Then President Anote Tong said that if necessary they could relocate the entire population of about 110,000 people to the land on Fiji.
“Among the small islands, Kiribati is the country that has done most to anticipate its population’s future needs,” said François Gemenne, a migration expert at Versailles-Saint Quentin University in France.
Like many small island nations, the Maldives are aggressively taking steps to build resilience into their many islands. They protect seaside vegetation to slow erosion and increase the use of rainwater to reduce drawdown of groundwater, which is suffering from saltwater intrusion. And they are flood-proofing waste management systems because poor solid waste management is a serious threat to their coral reefs, which are the first line of defense against storms and rising sea level. Structural methods are employed including raising critical infrastructure, and a seawall has been built around the island of Male, the capital. Then a few years ago the Maldives built an artificial island in a lagoon near the capital using dredged sand.
Several thousand Maldivians from other islands in the chain have moved there and more are expected as construction continues. The government of the Maldives is buying land in Australia in anticipation of relocating the country’s entire population of over 360,000 people.
Because of their population density, massive infrastructure, and expanses of concrete, urban areas resort primarily to structural engineering measures to combat sea level rise. Miami Beach has implemented an aggressive plan to hold back the sea that is estimated to eventually cost about half a billion dollars over the next five years.
Some roads and sidewalks have already been raised several feet, and a seawall and flood-pumping station are being installed along a road frequented by tourists. More than sixty underground pumps are planned that will suck water off the streets and dump it into Biscayne Bay. But the limestone foundation under southeast Florida is so porous that in the long run no amount of pumping will keep the water out. The environmental cost of pumping polluted runoff into Biscayne Bay has yet to be taken into account. Beyond the five-year plan, if structural engineering solutions are still considered viable, houses and buildings will have to be raised at a cost of billions of dollars. Home owners worry that at some point they will not be able to get mortgages because they won’t be able to get insurance; their homes and businesses will be worthless. One Miami Beach hotel tried a less-costly, low tech solution by giving guests plastic trash bags to put on their feet before stepping out the front door into flood waters. The Army Corps of Engineers estimates that Miami Beach will need tens of millions of cubic yards of sand to renourish its beaches multiple times over the next 50 years.
Like other urban areas, Charleston focused first on flooding in downtown streets. So far $235 million has been set aside for drainage improvement, and major projects were started more than 15 years ago. Charleston’s 2015 Sea Level Rise Strategy includes more infrastructure investment that would include raising roads and seawalls and initiatives such as setting building codes and design standards for a 50-year time horizon. Flooding problems in Charleston will be compounded as rising seas degrade the extensive salt marshes and erode the barrier islands that form the city’s first line of defense against storm surge. Charleston County requires that buildings be protected from a 1-in-100-year flood. By comparison, primary sea barriers in the Netherlands are required to withstand a 1-in-10,000- year storm. Finding the funding to implement many of the strategy’s initiatives will be a challenge. The prevailing attitude about climate change among South Carolina’s elected representatives makes it unlikely Charleston and the Lowcountry will get much sympathy or support at the state level to battle rising seas.
The Netherlands, a low-lying, densely populated country about the size of Maryland, has battled to hold back the North Sea for centuries.
Only half the country is more than three feet above sea level. A network of seawalls and coastal dunes protects the Netherlands from the sea, and levees and dikes along the rivers protect against river flooding. Having recognized the recent acceleration of sea level rise, the Netherlands is bolstering its flood protection system by building higher storm surge barriers, widening rivers, reinforcing the coastline, building floating homes, and providing an early warning system for evacuation. The 10,800 miles of coastal dunes, primary dikes, levees, and storm surge barriers have to meet legal safety standards which set minimum height and strength requirements for flood defenses based on the frequency of occurrence, or return period, of floods.
While the Netherlands is considered the world leader in flood control strategies, their technological solutions are enormously expensive and often exact a huge environmental toll on coastal ecosystems.
We should have been paying the cost of the effects of climate change and rising seas since the start of the industrial revolution. That didn’t happen because the way we measure economic well-being is flawed.
Gross domestic product (GDP) is the primary criterion for measuring economic growth, which is the most common indicator of economic well-being. But GDP fails to take into account environmental costs, such as the horrific consequences of greenhouse gas emissions. We haven’t paid the cost of those emissions as it was incurred, so we’ll have to pay it now. A 2013 study by the Organisation for Economic Cooperation and Development estimated that losses from flooding due to sea level rise and subsidence for the 136 largest cities worldwide would be about $1 trillion by 2050 unless better protective measures are put in place. The study estimates those new defenses would cost $50 billion a year.
Sea level rise and other effects of climate change are already severely disrupting the way of life of island nations and other lowlying coastal areas around the globe. But what we’ve seen so far is just the tip of the iceberg. A band aid approach to try and stay one step ahead of the rising water would be a woefully inadequate remedy. Governments at all levels need to begin developing and implementing enforceable, fully-funded, long-term plans to adapt effectively to rising seas.
Mr. Wildermann was an environmental specialist and manager with the federal offshore oil and gas program for over 25 years. He directed agency compliance with environmental laws and managed the analyses for proposals to lease to oil companies the rights to drill in federal waters. Mr. Wildermann was the sole U.S. Member of an international team that wrote the Guidelines for Environmental Impact Assessment in the Arctic. He currently works with nonprofit organizations in the Lowcountry in opposition to offshore seismic surveys and oil drilling.