Dear Ruben Carlo Asuncion and Minsoo Lee,
Your excellent January 2017 Asian Development Bank Economics Working Paper Series No.507, Impacts of Sea Level Rise on Economic Growth in Developing Asia, in concluding that shore protection could use up 10% of the GDP of Developing Asian countries, makes the point that shore protection against global sea level rise may be the largest, and the most ignored, cost of runaway climate change.
I have argued this very point in vain for nearly 30 years, but yours is the first systematic discussion I have ever seen of the crippling economic costs of shore protection against global sea level rise!
More than 25 years ago I met with UNDP, GEF, and other international agencies to find out who was helping countries with shore protection against rising sea level, and discovered that NO agency took any programmatic responsibility for the problem, but all were incorrectly sure somebody else must be……..
As a result there is essentially no proactive planning, only disaster responses, asking for immediate aid after existing seawalls fall down and roads, trees, beaches, houses, hospitals, and airports fall into the sea, in order to throw more concrete and rocks into the water, which only postpones the repetition until the next extreme storm event.
When I searched on “shore protection” to find out what the world spends to keep the waves from washing their beaches away, every single hit I got was for “offshore asset protection”: I learned nothing about shore protection, but found long lists of all the money-laundering banks in the world.
Your seawall cost estimate of $6 million per meter height protected per kilometer is close to typical figures of $10-15 million dollars per kilometer for typical sea walls that are 2-3 meters high.
In my view, your long term cost estimates are too low, because they assume sea level will rise at the present rate, when in fact dramatic increases are inevitable if we don’t reverse CO2 increase soon, which can be done at low cost and with great benefits:
The problem with sea walls is 1) they don’t work, and 2) they cost many times more than alternatives that do!
Every single seawall built in an atoll country has collapsed, or soon will, many fell down before they finished building them.
All coastal engineers know that sea walls are inevitably doomed to collapse and repeated rebuilding, because they concentrate erosive forces that wash away all sand in front of them, and then under them, until they fall down, but they think they have no other option. Our methods work like coral reefs do, dissipating wave energy that passes through them without being reflected.
I have worked with local teams on coral reef, sea grass, mangrove, and beach restoration projects in Indonesia, Philippines, Thailand, Malaysia, Viet Nam, and many Pacific Small Island Developing States, including the Marshall Islands, Palau, Vanuatu, Samoa, and Fiji.
Restoring these habitats works far better to protect shores at much lower cost than sea walls do, while providing vast additional economic benefits in ecosystem services like fisheries habitat and ecotourism.
In 2016 in Indonesia we had almost no coral mortality on our properly maintained projects while more than 95% of the corals in nearby reefs died from heat stroke, we grew back a severely eroded beach naturally in just a few months, and socioeconomic studies showed that these projects had turned the poorest villages on their islands into some of the most prosperous because of the huge number of people coming from all over the world to swim in beautiful corals and fishes.
Our methods work rapidly where all other restoration methods fail because only our method causes much higher settlement, growth, survival, and resistance to environmental stress of all forms of life. These results are because only our method directly enhances their natural biochemical energy generating mechanisms.
Adapting to sea level rise need not be as costly as your study indicates when the new state-of-the-art ecosystem restoration measures are considered as an alternative to hard shoreline protection.
The sooner that they are, the sooner we can move forward to much more effective solutions with lower costs and higher benefits.
Thomas J. F. Goreau, PhD
President, Global Coral Reef Alliance
President, Biorock Technology Inc.
Coordinator, Soil Carbon Alliance
Coordinator, United Nations Commission on Sustainable Development Small Island Developing States Partnership in New Sustainable Technologies
37 Pleasant Street, Cambridge, MA 02139
Tel: (1) 617-864-4226